CN100590954C - Multi-output current-resonant type DC-DC converter - Google Patents

Abstract

A multi-output current-resonant type DC-DC converter comprises an output controlling MOS-FET (40) connected between a second secondary winding (5c) of a transformer (5) and a second output smoothing capacitor (16) of a second rectification smoothing circuit (17), and an output control circuit (41) for controlling the ON/OFF of an output controlling MOS-FET (40) on the basis of the voltage V<SUB>02</SUB> of the second output smoothing capacitor (16). By turning ON/OFF the output controlling MOS-FET (40) in synchronism with the switching frequency of a first or second main MOS-FET (1, 2), it ismade possible to achieve an ideal cross regulation with each DC output and to achieve a highly stable DC output with a little power conversion loss and with a simple circuit change. The multi-output current-resonant type DC-DC converter realized is inexpensive but high in the power conversion efficiency, and can have a highly precise DC output.

Description

Multi-output current-resonant type DC-DC converter

Technical field

The present invention relates to take place the multi-output current-resonant type DC-DC converter of a plurality of direct current outputs, particularly relate to by the output that reduces primary side and controlling, seek to improve the current-resonance type DC-DC converter of combined power conversion efficiency with the switching losses in the switch element.

Background technology

On-off action by switch element is transformed to the elementary winding that High frequency power is input to transformer to the direct current input from DC power supply, be transformed to direct current power once more by the rectifier smoothing circuit on a plurality of secondary winding that are connected to transformer, multi-output type DC-current the extensive application of DC converter that obtains the output of a plurality of direct currents from each rectifier smoothing circuit is at information equipments such as personal computers, perhaps household appliances such as air conditioner or audio and video equipment medium in.For example, multi-output type DC in the past-DC converter shown in Figure 35 possesses: conduct the 1st that is connected in series for DC power supply (3) and the 1st and the 2nd main MOS-FET (1 of the 2nd switch element, 2), the current resonance that is connected in parallel for the 2nd main MOS-FET (2) is with capacitor (4), the leakage inductance (5d) of transformer (5) and the series circuit of elementary winding (5a), be connected voltage analog vibration between drain electrode-source electrode of the 1st main MOS-FET (1) with capacitor (6), anode be connected transformer (5) first secondary winding (5b) an end the 1st output rectifier diode (7), be connected the negative electrode of the 1st output rectifier diode (7) and the 1st output smoothing capacitor (8) between the other end of first secondary winding (5b), anode be connected transformer (5) second subprime winding (5c) an end the 2nd output rectifier diode (15), be connected the negative electrode of the 2nd output rectifier diode (15) and the 2nd output smoothing capacitor (16) between the other end of second subprime winding (5c), be connected the buck circuit (30) on the 2nd output smoothing capacitor (16).The 1st output rectifier diode (7) and the 1st output smoothing capacitor (8) constitute the 1st rectifier smoothing circuit (9), through the 1st dc output end (10,11) the 1st VD V take place _O1The 2nd output rectifier diode (15) and the 2nd output smoothing capacitor (16) constitute the 2nd rectifier smoothing circuit (17), from the 2nd dc output end (18,19) the 2nd VD V take place through buck circuit (30) _O2

Transformer (5) has the auxiliary winding (5f) with elementary winding (5a) electromagnetic coupled, and elementary winding (5a) has leakage inductance (5d) and magnetizing inductance (5e).Leakage inductance (5d) is connected in series with elementary winding (5a) equivalently, and magnetizing inductance (5e) is connected in parallel with elementary winding (5a) equivalently.Leakage inductance (5d) plays a role with choke as current resonance.In auxiliary winding (5f), connect the auxiliary rectifier smoothing circuit (22) that constitutes by auxiliary rectifier diode (20) and auxiliary smmothing capacitor (21), at driving power terminal (V as the main control circuit (14) of primary side control circuit _CC) the middle direct current power that drives usefulness of supplying with.Between the positive terminal of DC power supply (3) and auxiliary smmothing capacitor (21), be connected starting resistance (23), during the device starting, from DC power supply (3) through starting resistance (23) to auxiliary smmothing capacitor (21) charging, make main control circuit (14) starting.Between the tie point of starting resistance (23) and the 1st and the 2nd main MOS-FET (1,2), connect and compose the rectifier diode (24) and the smmothing capacitor (25) of boostrap circuit, at the power supply terminal (V of the high-end side of main control circuit (14) _B, V _S) between supply with direct current power.The two ends that constitute the 1st output smoothing capacitor (8) of the 1st rectifier smoothing circuit (9) connect the 1st output voltage detecting circuit (12), and the 1st output voltage detecting circuit (12) detects from the 1st VD V of the 1st rectifier smoothing circuit (9) output _O1, the reference voltage and the 1st VD V of regulation the 1st output voltage values _O1Detection voltage compare, its error signal V _E1Output to the luminescence unit (13a) of photoelectrical coupler (13).The luminescence unit (13a) of photoelectrical coupler (13) sends and error signal V to the photosensitive unit (13b) of photoelectrical coupler (13) _E1The light of big or small corresponding intensity, photosensitive unit (13b) is to feedback signal input terminal (FB) the transmission error signal V of main control circuit (14) _E1

As shown in figure 36, main control circuit (14) is by the with good grounds luminescence unit (13a) of photoelectrical coupler (13) and the error signal V of the 1st output voltage detecting circuit (12) that photosensitive unit (13b) is input to feedback signal input terminal (FB) of passing through of output device _E1Voltage level and the pulse signal V of the frequency that changes _PLOscillator (32), output from the pulse signal V of oscillator (32) output _PLInversion signal-V _PLInverter (33), to pulse signal V from oscillator (32) output _PLThe Dead Time of additional certain hour forms the 1st drive signal V _G1The 1st Dead Time adjunct circuit (34), the 1st drive signal V that has added Dead Time _G1Be provided to the grid of the 1st main MOS-FET (1) low side buffer amplifier (35), from oscillator (32) through inverter (33) output pulse signal-V _PLThe Dead Time of going up additional certain hour forms the 2nd drive signal V _G2The 2nd Dead Time adjunct circuit (36), to having added the 2nd drive signal V of Dead Time _G2Voltage level carry out the level-conversion circuit (37) of conversion, the 2nd drive signal V from level-conversion circuit (37) output _G2The high distolateral buffer amplifier (38) that is provided to the grid of the 2nd main MOS-FET (2) constitutes.The pulse signal V of frequency change _PLPulse duration by because be certain, therefore provide fixing conduction period and according to the error signal V of output voltage detecting circuit (12) to each grid of the 1st and the 2nd main MOS-FET (1,2) respectively from main control circuit (14) _E1The 1st drive signal V that changes of voltage level blocking interval _G1, and fixing blocking interval and according to the error signal V of output voltage detecting circuit (12) _E1The 2nd drive signal V that changes of voltage level conduction period _G2, according to the error signal V of the 1st output voltage detecting circuit (12) _E1Voltage level, the 1st and the 2nd main MOS-FET (1,2) alternatively carries out conducting/shutoff action.

As shown in figure 35, buck circuit (30) is by the copped wave MOS-FET (26) that has connected drain electrode on the tie point of the 2nd output rectifier diode (15) that constitutes the 2nd rectifier smoothing circuit (17) and the 2nd output smoothing capacitor (16), be connected the copped wave source electrode of MOS-FET (26) and the fly-wheel diode (27) between the primary side ground connection terminal, copped wave with the tie point of the source electrode of MOS-FET (26) and the negative electrode of fly-wheel diode (27) on the connected filter choke coil of one end (28), the other end and the filter rectifier (29) between the primary side ground connection terminal that are connected filter choke coil (28) constitute.Control circuit of chopping (31) is at the reference voltage (not shown) that is built-in with regulation the 2nd output voltage values, based on the voltage V in the generation of the two ends of filter capacitor (29) _O2With the error signal of the reference voltage of stipulating the 2nd output voltage values, output pulse width modulation (PWM) signal V _S2Buck circuit (30) is according to pulse-width modulation (PWM) the signal V from control circuit of chopping (31) output _S2, the control copped wave break-make of MOS-FET (26), the 2nd VD V of certain level that the direct current of the 2nd output smoothing capacitor (16) input from the 2nd dc output end (18,19) output ratio from the 2nd rectifier smoothing circuit (17) forces down _O2

When existing multi-output current-resonant type DC-DC converter shown in Figure 35 is moved, after not shown mains switch is connected, the voltage E of DC power supply (3) is applied on the auxiliary smmothing capacitor (21) of auxiliary rectifier smoothing circuit (22) through starting resistance (23), and auxiliary smmothing capacitor (21) is charged.After the charging voltage of auxiliary smmothing capacitor (21) reached the starting voltage of main control circuit (14), main control circuit (14) began action.At this moment, on each grid of the 1st and the 2nd main MOS-FET (1,2), provide the 1st and the 2nd drive signal V from main control circuit (14) respectively _G1, V _G2, the 1st and the 2nd main MOS-FET (1,2) begins on-off action.When the 1st main MOS-FET (1) conducting, through the path flow overcurrent I of DC power supply (3), current resonance capacitor (4), the leakage inductance (5d) of transformer (5), elementary winding (5a), the 1st main MOS-FET (1) and DC power supply (3) _Q1At this moment, be subjected to first secondary winding (5b) at transformer (5), the 1st influence of exporting first secondary current that flows through in the path of rectifier diode (7) and the 1st output smoothing capacitor (8) of the 1st rectifier smoothing circuit (9), in the path of current resonance, flow through the 1st load current with capacitor (4), the leakage inductance (5d) of transformer (5), elementary winding (5a) and the 1st main MOS-FET (1).In addition, be subjected to the second subprime winding (5c) at transformer (5), the 2nd influence of exporting the second subprime electric current that flows through in the path of rectifier diode (15) and the 2nd auxiliary smmothing capacitor (16) of the 2nd rectifier smoothing circuit (17), in the path of current resonance, flow through the 2nd load current with capacitor (4), the leakage inductance (5d) of transformer (5), elementary winding (5a) and the 1st main MOS-FET (1).And then, in the path of current resonance, flow through exciting current with leakage inductance (5d), magnetizing inductance (5e) and the 1st main MOS-FET (1) of capacitor (4), transformer (5).Thereby, the electric current I that flows through along the 1st main MOS-FET (1) _O1Become the resultant current of the 1st load current, the 2nd load current and exciting current.The the 1st and the 2nd load current is to have by the sinuous resonance current of current resonance with the resonance frequency of the electrostatic capacitance of capacitor (4) and the decision of the leakage inductance (5d) of transformer (5).Exciting current is the resonance current that has by the resonance frequency of the electrostatic capacitance decision of the combination inductance of the leakage inductance (5d) of transformer (5) and magnetizing inductance (5e) and current resonance capacitor (4), its resonance frequency is because lower than the conduction period of the 1st main MOS-FET (1), therefore is observed sinuous load current and is the wavy electric current of triangle of hypotenuse with the part of sine wave.

Have no progeny when the 1st main MOS-FET (1) closes,, the voltage analog vibration takes place, the voltage V between drain electrode-source electrode of the 1st and the 2nd main MOS-FET (1,2) according to the energy that is stored in by exciting current in the transformer (5) _Q1, V _Q2Become by the combination inductance of the leakage inductance (5d) of transformer (5) and magnetizing inductance (5e) and current resonance with capacitor (4) and voltage analog vibration simulation oscillating voltage with the resonance frequency of the synthetic electrostatic capacitance decision of capacitor (6).That is, if the 1st main MOS-FET (1) shutoff, the then electric current I that in the 1st king MOS-FET (1), flows through _Q1Commutate to the voltage analog vibration with capacitor (6), according to this current of commutation, voltage analog vibrates and is charged to the voltage E of DC power supply (3) with capacitor (6), simultaneously, and the electric current I that in the 1st main MOS-FET (1), flows through _Q1Also commutate to the not shown diode-built-in of the 2nd main MOS-FET (2).That is, the energy by the exciting current generation that is stored in transformer (5) uses capacitor (4) to charge through the not shown diode-built-in of the 2nd main MOS-FET (2) to current resonance.Thereby, in this period, can reach the no-voltage break-make (ZVS) of the 2nd main MOS-FET (2) that is switched to conducting.

After the release of the energy that is produced by exciting current in being stored in transformer (5) finishes, according to the energy that is stored in the current resonance usefulness capacitor (4), in magnetizing inductance (5e), leakage inductance (5d) and current resonance the path with capacitor (4) of current resonance, flow through circulating current, release energy with capacitor (4), the 2nd main MOS-FET (2), transformer (5).That is, flow through the exciting current of transformer (5) along the direction opposite with the conduction period of the 1st main MOS-FET (1).This exciting current is to have by the combination inductance of the leakage inductance (5d) of transformer (5) and magnetizing inductance (5e) and the current resonance resonance current with the resonance frequency of the electrostatic capacitance decision of capacitor (4), and become low resonant frequency owing to comparing with the conduction period of the 2nd main MOS-FET (2), therefore a part that is observed with sine wave is the electric current of the triangular waveform of hypotenuse.

Figure 37 (A) and (B) expression when the input voltage E that supplies with from DC power supply (3) is high and when low respectively, fix the conduction period of the 1st main MOS-FET (1) and also make the 2nd main MOS-FET (2) conduction period, variation was controlled the time drain electrode-voltage between source electrodes V of the 1st main MOS-FET (1) _Q1, electric current I between drain electrode-source electrode _Q1And the current resonance waveform of the voltage Vc2 at capacitor (4) two ends.That is, Figure 37 (A) and (B) expression make the conduction period of the 2nd main MOS-FET (2) variable for the variation of input voltage E, control the conducting duty ratio of the 1st main MOS-FET (1), make the voltage V of current resonance with capacitor (4) two ends _C2The state that changes.Thus, because the change in voltage of the elementary winding (5a) of transformer (5) therefore can be controlled the 1st VD V _O1Figure 37 (C) and (D) when representing respectively that load is light and the voltage V of load when heavy _Q1, V _C2And electric current I _Q1Waveform.That is, in Figure 37 of light-load state (C), the electric current I that in the 1st main MOS-FET (1), flows through _Q1Become roughly triangular waveform, flow through resonance current hardly as load current, and in Figure 37 of heavy duty state (D), the electric current I that in the 1st main MOS-FET (1), flows through _Q1Comprise being the part that sinusoidal wave shape changes, flow through the resonance current suitable with load current.In addition, according to by current resonance with the resonance frequency decision of leakage inductance (5d) decision of capacitor (4) and transformer (5) from the primary side of transformer (5) during the primary side supply capability.Thereby even load change, the conduction period of the 1st main MOS-FET (1), promptly the primary side from transformer (5) also changes during the primary side supply capability hardly.Drain electrode-voltage between source electrodes V from the 1st main MOS-FET (1) _Q1Become 0V during, promptly the conduction period of the 1st main MOS-FET (1) is at Figure 37 (C) and roughly the samely (D) also can affirm this point.

Figure 38 represents for the variation than (Duty Ratio, duty ratio) of conduction period of the 1st main MOS-FET (1) and the 2nd main MOS-FET (2), the 1st VD V _O1Variation.As shown in figure 38, in multi-output current-resonant type DC-DC converter in the past shown in Figure 35, the ratio of the conduction period of the 1st main MOS-FET (1) and the 2nd main MOS-FET (2) is changed in 0.3 to 1.0 scope, can adjust from the 1st VD V of the 1st dc output end (10,11) output _O1That is, the rate of change of the conduction period by making the 1st main MOS-FET (1) and the 2nd main MOS-FET (2) is adjusted the charging voltage V of current-resonance type with capacitor (4) _O2, control the voltage on the elementary winding (5a) that is applied to transformer (5), may command process transformer (5) first secondary winding (5b) and the 1st rectifier smoothing circuit (9) are from the 1st VD V of the 1st dc output end (10,11) output _O1

Detect the 1st VD V that goes up generation at the 1st dc output end (10,11) by the 1st output voltage detecting circuit (12) _O1, stipulate the error signal V of the detection voltage of the reference voltage of the 1st output voltage values and the 1st output voltage detecting circuit (12) _E1Through the luminescence unit (13a) and the photosensitive unit (13b) of photoelectrical coupler (13), be delivered to the feedback signal input terminal (FB) of main control circuit (14).Main control circuit (14) is according to the error signal V that is input to the 1st output voltage detecting circuit (12) of feedback signal input terminal (FB) _E1Voltage level the 1st and the 2nd drive signal V that provides modulation (PFM) pulse frequency respectively to each grid of the 1st and the 2nd main MOS-FET (1,2) _G1, V _G2, with the error signal V of the 1st output voltage detecting circuit (12) _E1The corresponding frequency of voltage level make the mutual on-off action of the 1st and the 2nd main MOS-FET (1,2).Thus, the 1st VD V that exports from the 1st dc output end (10,11) _O1Be controlled so as to roughly certain value.

By the on-off action of the 1st and the 2nd main MOS-FET (1,2), the voltage of induction is applied to the 2nd rectifier smoothing circuit (17) in the second subprime winding (5c) of transformer (5).At this moment, take place corresponding to first secondary winding (5b) of transformer (5) and the direct voltage of the turn ratio of second subprime winding (5c) at the two ends of the 2nd output smoothing capacitor (16).The direct voltage that takes place at the two ends of the 2nd output smoothing capacitor (16) is applied to buck circuit (30).The voltage V that two ends at filter capacitor (29) take place control circuit of chopping (31) _O2Compare with the reference voltage of regulation the 2nd output voltage values, take place based on their pulse-width modulation (PWM) the signal V of the corresponding error signal of error _S2According to pulse-width modulation (PWM) signal V from control circuit of chopping (31) output _S2, buck circuit (30) control copped wave thus, is exported the 2nd VD V of the certain level that forces down than the direct current that is applied on the 2nd output smoothing capacitor (16) with the break-make of MOS-FET (26) from the 2nd dc output end (18,19) _O2

Because in the multi-output dc-DC converter of general flyback mode or forward manner, make the break-make change in duty cycle of the main switch element that is arranged on primary side, control the direct current output of taking out from primary side, therefore the primary side from transformer (5) changes during the primary side supply capability.Thereby, according to the above-mentioned duty ratio that the direct voltage from secondary winding one a side output determines, the electric power that restriction is taken out from another secondary winding, the output voltage of another secondary winding one side reduces.Different therewith, in multi-output current-resonant type DC-DC converter, because the resonance frequency that is determined with the leakage inductance (5d) of capacitor (4) and transformer (5) according to the current resonance that is arranged on primary side determines primary side from transformer (5) during the primary side supply capability, even it is therefore be connected the load change on the 1st dc output end (10,11), also almost constant during the primary side supply capability from the primary side of transformer (5).Thereby, because can be irrelevant, take out needed electric power from the second subprime winding (5c) of transformer (5) with the size of load, therefore can not reduce the output voltage of the 2nd rectifier smoothing circuit (17).Yet, in fact transformer (5) does not constitute desirable electromagnetic coupled, in addition, be subjected to the influence that produces by change or the voltage drop in the 1st rectifier smoothing circuit (9), the output voltage change of the 2nd rectifier smoothing circuit (17) from the input voltage E of DC power supply (3).Thereby, in multi-output current-resonant type DC-DC converter in the past shown in Figure 35, by the stable direct voltage of buck circuit (30), can obtain the 2nd stable VD V from the 2nd dc output end (18,19) from the 2nd rectifier smoothing circuit (17) output _O2That is,, then can realize to carry out the multi-output current-resonant type DC-DC converter of desirable mutual adjusting if buck circuit (30) is set in the back one-level of the 2nd rectifier smoothing circuit (17).So-called adjusting mutually refers in multi-output power supply, the output voltage fluctuation when having changed other output loading in predetermined scope.

In addition, (spy opens (the 5th page in flat 3-7062 communique to following patent documentation 1, the 1st figure)) disclosed resonance type switching power source is by frequency modulator reference pulse signal to be carried out frequency modulation(FM) to be transformed into pulse sequence signal in, according to pulse sequence signal, make the power transistor break-make of primary side, control is for the voltage that applies of transformer primary winding, the power supply that the level and smooth back of the output rectification that takes place in a plurality of primary side windings is taken out by each rectifier smoothing circuit.In this resonance type switching power source, by the comparator that constitutes the primary side control unit, according to the pre-set output signal of the rectifier smoothing circuit that is arranged on primary side, control is from the frequency of the pulse sequence signal of frequency modulator output.In addition,, make switching transistor work, be controlled at the duty cycle of the pulse train voltage that output one side of switching transistor takes place by the control circuit of primary side according to the pre-set output signal of direct current smoothing circuit for the primary side winding.Thus, the pulse train voltage that takes place in output one side of switching transistor is extracted appropriate amount, can be adjusted to predetermined level to the VD for the direct current smoothing circuit of primary side winding.

In addition, in following patent documentation 2 (spy opens 2000-217356 communique (Fig. 2 of the 4th page and the 5th page Fig. 1)), multi-output dc/DC converter is disclosed, this DC/DC converter is by the transformer that has elementary winding and carry out two secondary winding of power converter, be connected to the elementary winding of transformer and the field-effect transistor that carries out switch motion, detect the 1st voltage detecting circuit of the later output voltage of first secondary winding of transformer output having stablized, the detection output and the reference voltage of the 1st voltage detecting circuit are compared, control the 1st pulse width control circuit of the pulsewidth of the pulse control signal that outputs to field-effect transistor, be connected to the switching circuit of an end of the second subprime winding of transformer, the 2nd voltage detecting circuit of the output voltage after the rectification of the second subprime winding output of detection transformer is level and smooth, the detection output of the 2nd voltage detecting circuit and reference voltage are compared the 2nd pulse width control circuit of pulsewidth that control outputs to the pulse signal of switching circuit, make the output of the 2nd pulse width control circuit and the synchronous synchronous circuit formation of output of the 1st pulse width control circuit.In this multi-output dc/DC converter, because by in the second subprime winding output of the transformer of the output system of mainly not feeding back, switching circuit being set, output voltage with the output system of mainly not feeding back, the ON time of control switch circuit, for output voltage stabilization, even the load change of the output system of mainly feeding back increases, also can reduce the loss.

Summary of the invention

The problem that invention will solve

Yet, in multi-output current-resonant type DC-DC converter in the past shown in Figure 35, owing to after the ac voltage rectifier of responding in the second subprime winding (5c) at transformer (5) with the 2nd rectifier smoothing circuit (17) and smooth transformation are direct voltage, be transformed to the 2nd VD V of the certain level that forces down than the direct current of importing from the 2nd rectifier smoothing circuit (17) once more with buck circuit (30) _O2, therefore power loss takes place in buck circuit (30), have the shortcoming that power converter efficient reduces.In addition, the buck circuit (30) that is made of with MOS-FET (26), fly-wheel diode (27), filter choke coil (28) and filter capacitor (29) copped wave has increases the shortcoming that the number of components manufacturing cost raises.And then, in patent documentation 1 in the disclosed resonance type switching power source, because basis is for the predetermined output of the rectifier smoothing circuit of primary side winding, control circuit by primary side makes switching transistor carry out on-off action, the pulse train voltage extracting appropriate amount that produces in output one side of switching transistor, adjust the VD of rectifier smoothing circuit, the ripple component that therefore has VD increases, and can not obtain the shortcoming of high accuracy direct current output.

Therefore, in the present invention, the multi-output current-resonant type DC-DC converter that purpose is to provide power converter efficient height and can obtains the cheapness of high accuracy direct current output.In addition, in the present invention, purpose is to reduce the multi-output current-resonant type DC-DC converter of the output control of primary side with the raising of the switching losses in switch element power converter efficient.And then in the present invention, purpose is to absorb or to relax the multi-output current-resonant type DC-DC converter of the current concentration that takes place in primary side.

Be used to solve the method for problem

Multi-output current-resonant type DC-DC converter of the present invention has the 1st switch element (1) and the 2nd switch element (2) that is connected in series for DC power supply (3), for the 1st or the 2nd switch element (1,2) current resonance that is connected in parallel capacitor (4), the series circuit of the elementary winding (5a) of inductor (5d) and transformer (5), be connected to the 1st rectifier smoothing circuit (9) of first secondary winding (5b) of transformer (5), be connected to the 2nd rectifier smoothing circuit (17) of the second subprime winding (5c) of transformer (5).According to the on-off action of the 1st and the 2nd switch element (1,2), export V through the 1st rectifier smoothing circuit (9) taking-up the 1st direct current from first secondary winding (5b) of transformer (5) _O1The time, export V from the second subprime winding (5c) of transformer (5) through the 2nd rectifier smoothing circuit (17) taking-up the 2nd direct current _O2This multi-output current-resonant type DC-DC converter possess at the level winding (5c) for the third time of transformer (5) and constitute the output control switch element (40) that connects between the smmothing capacitor (16) of the 2nd rectifier smoothing circuit (17), based on the voltage V of the smmothing capacitor (16) of the 2nd rectifier smoothing circuit (17) _O2, the output control circuit (41) of the break-make of control output control switch element (40).

Since according to by current resonance with the resonance frequency decision of capacitor (4) and inductor (5d) decision from the primary side of transformer (5) during the primary side supply capability, even therefore the load change of primary side is also constant during the primary side supply capability from the primary side of transformer (5).Therefore, irrelevant with the load change of the first primary side winding (5b) side of transformer (5), can take out needed direct voltage through the 2nd rectifier smoothing circuit (17) from the second subprime winding (5c) of transformer (5).In addition, since output control circuit (41) and the 1st and the 2nd switch element (1,2) switching frequency synchronously and according to the voltage V of the 2nd smmothing capacitor (16) _O2Level, make output control switch element (40) break-make, control from the second subprime winding (5c) of transformer (5) to the smmothing capacitor (16) of the 2nd rectifier smoothing circuit (17) flow through electric current during, therefore can control the 2nd direct current output V accurately from the 2nd rectifier smoothing circuit (17) output _O2Level.Like this, directly control the 2nd direct current output V that exports from the 2nd rectifier smoothing circuit (17) owing to pass through the on-off action of output control switch element (40) _O2Therefore, it is few to obtain the power converter loss, just appends easy circuit change such as switch element (40) in addition and just can obtain high stability the 2nd direct current and export V on the 2nd rectifier smoothing circuit (17) _O2Thereby, can realize that power converter efficient is high and the multi-output current-resonant type DC-DC converter of the cheapness of high accuracy direct current output takes place.

In addition, in multi-output current-resonant type DC-DC converter of the present invention, because output control circuit (41) possesses the rising edge pulse and the trailing edge pulse of the voltage that detection takes place in any secondary winding of transformer (5), the voltage-change detecting circuit (42) of the 1st detection signal and the 2nd detection signal takes place respectively, after the 1st detection signal and the 2nd detection signal have taken place in voltage-change detecting circuit (42), output control is switched to the Drive and Control Circuit (44) of connecting and disconnecting respectively with switch element (40), therefore not to export the switch motion of control independently with switch element (40), but in fact with the 1st or the 2nd switch element (1,2) switch motion is synchronous, reach Zero Current Switch (ZCS), can reduce output and control with the switching losses in the switch element (40).

In addition, multi-output current-resonant type DC-DC converter of the present invention has: first switch element and the second switch element that are connected in series for DC power supply; The current resonance that is connected in parallel for above-mentioned first switch element or second switch element is with the series circuit of the elementary winding of capacitor, inductor and transformer; First rectifier smoothing circuit is connected in first secondary winding of above-mentioned transformer; And second rectifier smoothing circuit, be connected in the second subprime winding of above-mentioned transformer, by above-mentioned first and the on-off action of second switch element, through above-mentioned current resonance capacitor, inductor, the elementary winding of transformer and above-mentioned first switch element or second switch element flow through resonance current, take out the output of first direct current from first secondary winding of above-mentioned transformer through above-mentioned first rectifier smoothing circuit, second subprime winding from above-mentioned transformer takes out the output of second direct current through above-mentioned second rectifier smoothing circuit simultaneously, described multi-output current-resonant type DC-DC converter is characterised in that and comprises: switch element use in output control, is connected between the smmothing capacitor of the second subprime winding of above-mentioned transformer and above-mentioned second rectifier smoothing circuit of formation; And output control circuit, voltage based on above-mentioned smmothing capacitor, control the break-make of above-mentioned output control with switch element, wherein above-mentioned output control circuit and above-mentioned first or the switching frequency of second switch element synchronous, make above-mentioned output control switch element break-make, after switch element (40) conducting is used in above-mentioned output control, voltage is applied on the leakage inductance (5d), this voltage is that the voltage from the magnetizing inductance (5e) that is applied to above-mentioned inductor (5d) and above-mentioned transformer (5) deducts resulting voltage behind a certain voltage, and this a certain voltage equals the voltage that elementary winding (5a) and the turn ratio of second subprime winding (5c) multiply by the second subprime winding.

In addition, multi-output current-resonant type DC-DC converter of the present invention has: first switch element and the second switch element that are connected in series for DC power supply; The current resonance that is connected in parallel for above-mentioned first switch element or second switch element is with the series circuit of the elementary winding of capacitor, inductor and transformer; First rectifier smoothing circuit is connected in first secondary winding of above-mentioned transformer; And second rectifier smoothing circuit, be connected in the second subprime winding of above-mentioned transformer, by above-mentioned first and the on-off action of second switch element, through above-mentioned current resonance capacitor, inductor, the elementary winding of transformer and above-mentioned first switch element or second switch element flow through resonance current, take out the output of first direct current from first secondary winding of above-mentioned transformer through above-mentioned first rectifier smoothing circuit, second subprime winding from above-mentioned transformer takes out the output of second direct current through above-mentioned second rectifier smoothing circuit simultaneously, described multi-output current-resonant type DC-DC converter is characterised in that and comprises: switch element use in output control, is connected between the smmothing capacitor of the second subprime winding of above-mentioned transformer and above-mentioned second rectifier smoothing circuit of formation; And output control circuit, voltage based on above-mentioned smmothing capacitor, control the break-make of above-mentioned output control with switch element, wherein above-mentioned output control circuit possesses: voltage-change detecting circuit, the rising edge pulse of the voltage that detection takes place in any secondary winding of above-mentioned transformer, first detection signal takes place, detect the trailing edge pulse of the voltage that takes place in any secondary winding of above-mentioned transformer, second detection signal takes place; Drive and Control Circuit after first detection signal or second detection signal have taken place above-mentioned voltage-change detecting circuit, switches to conducting or shutoff to above-mentioned output control respectively with switch element.

In addition, multi-output current-resonant type DC-DC converter of the present invention has: first switch element and the second switch element that are connected in series for DC power supply; The current resonance that is connected in parallel for above-mentioned first switch element or second switch element is with the series circuit of the elementary winding of capacitor, inductor and transformer; First rectifier smoothing circuit is connected in first secondary winding of above-mentioned transformer; And second rectifier smoothing circuit, be connected in the second subprime winding of above-mentioned transformer, by above-mentioned first and the on-off action of second switch element, through above-mentioned current resonance capacitor, inductor, the elementary winding of transformer and above-mentioned first switch element or second switch element flow through resonance current, take out the output of first direct current from first secondary winding of above-mentioned transformer through above-mentioned first rectifier smoothing circuit, second subprime winding from above-mentioned transformer takes out the output of second direct current through above-mentioned second rectifier smoothing circuit simultaneously, described multi-output current-resonant type DC-DC converter is characterised in that and comprises: switch element use in output control, is connected between the smmothing capacitor of the second subprime winding of above-mentioned transformer and above-mentioned second rectifier smoothing circuit of formation; And output control circuit, voltage based on above-mentioned smmothing capacitor, control the break-make of above-mentioned output control with switch element, wherein at above-mentioned second subprime winding, above-mentioned second rectifier smoothing circuit and above-mentioned output control are with in the formed closed-loop path of switch element, be connected with choke, after switch element (40) conducting is used in above-mentioned output control, voltage is applied on the leakage inductance (5d), this voltage is that the voltage from the magnetizing inductance (5e) of leakage inductance that is applied to above-mentioned transformer and above-mentioned transformer (5) deducts resulting voltage behind a certain voltage, the turn ratio that this a certain voltage equals elementary winding (5a) and second subprime winding (5c) multiply by the voltage of second subprime winding, above-mentioned output control circuit comprises: voltage-change detecting circuit, detect the voltage rising edge pulse that takes place in certain secondary winding of above-mentioned transformer and first detection signal takes place, detect the voltage trailing edge pulse that takes place in certain secondary winding of transformer and second detection signal takes place, and Drive and Control Circuit, after first detection signal takes place in above-mentioned voltage-change detecting circuit, above-mentioned output control is switched to conducting with switch element, after second detection signal takes place in above-mentioned voltage-change detecting circuit, when the back level does not connect holding circuit, above-mentioned output control is switched to shutoff with switch element, when the back level is connected with holding circuit, by holding circuit, turn-offing the constant time lag of above-mentioned output control with switch element.

And then, in multi-output current-resonant type DC-DC converter of the present invention, because therefore series-diode limiter (100) in the closed circuit that is formed with switch element (40) by second subprime winding (5c), the 2nd direct current smoothing circuit (17) and output control can absorb or relax current concentration or the inrush current that takes place in specific output.

The effect of invention

According to the present invention, the switching frequency Synchronization Control break-make of the switch element that is provided with by second subprime winding one side that makes transformer and the switch element of primary side, can be irrelevant with the size of exporting from the direct current of any direct current smoothing circuit output, directly and accurately control direct current output, in each direct current output, can obtain desirable mutual adjusting from the output of the 2nd rectifier smoothing circuit.In addition, can absorb or relax the current concentration or the inrush current that in specific output, take place, prolong component life and improve power converter efficient.

Description of drawings

Fig. 1 is the circuit diagram of the 1st example of expression multi-output current-resonant type DC-DC converter of the present invention.

Fig. 2 is the circuit block diagram of internal structure of the output control circuit of presentation graphs 1.

Fig. 3 is the each several part voltage of circuit of presentation graphs 1 and the oscillogram of electric current.

Fig. 4 is the circuit diagram of expression the present invention the 2nd example.

Fig. 5 is the circuit diagram of expression the present invention the 3rd example.

Fig. 6 is the circuit diagram of expression the present invention the 4th example.

Fig. 7 is the circuit diagram of expression the present invention the 5th example.

Fig. 8 is the circuit block diagram of internal structure of the main control circuit of presentation graphs 7.

Fig. 9 is expression for the each several part voltage of the change of the change of the input voltage of the circuit of Fig. 7 and load and the oscillogram of electric current.

Figure 10 is the each several part voltage of circuit of presentation graphs 7 and the oscillogram of electric current.

Figure 11 is the circuit diagram of expression the present invention the 6th example.

Figure 12 is the circuit diagram of expression the present invention the 7th example.

Figure 13 is the circuit diagram of expression the present invention the 8th example.

Figure 14 is the circuit diagram of expression the present invention the 9th example.

Figure 15 is the circuit diagram of expression the present invention the 10th example.

Figure 16 is the circuit diagram of expression the present invention the 11st example.

Figure 17 is the circuit diagram of the change example of presentation graphs 1.

Figure 18 is the circuit diagram of the change example of presentation graphs 7.

Figure 19 is the circuit diagram of the 12nd example of expression multi-output current-resonant type DC-DC converter of the present invention.

Figure 20 is the circuit diagram of detailed structure of the output control circuit of expression Figure 19.

Figure 21 is expression Figure 19 and the each several part voltage of Figure 20 and the oscillogram of electric current.

Figure 22 is the circuit diagram of expression the present invention the 13rd example.

Figure 23 is the circuit diagram of expression the present invention the 14th example.

Figure 24 is the circuit diagram of expression the present invention the 15th example.

Figure 25 is the circuit diagram of expression the present invention the 16th example.

Figure 26 is the circuit diagram of expression the present invention the 17th example.

Figure 27 is the each several part voltage of expression circuit shown in Figure 26 and the oscillogram of electric current.

Figure 28 is that expression is for the curve chart of the characteristic of the power converter efficient of the output power of circuit and circuit of the present invention in the past.

Figure 29 is the curve chart of expression for the output voltage characteristic of the output current of in the past circuit and circuit of the present invention.

Figure 30 is the circuit diagram of expression the present invention the 18th example.

Figure 31 is the circuit diagram of the 1st change example of expression Figure 26.

Figure 32 is the circuit diagram of the 2nd change example of expression Figure 26.

Figure 33 is the circuit diagram of the 3rd change example of expression Figure 26.

Figure 34 is the circuit diagram of the 4th change example of expression Figure 26.

Figure 35 is a circuit diagram of representing multi-output current-resonant type DC-DC converter in the past.

Figure 36 is the circuit block diagram of internal structure of the main control circuit of expression Figure 35.

Figure 37 is input voltage change and the each several part voltage of load change and the oscillogram of electric current of expression for the circuit of Figure 35.

Figure 38 be expression Figure 35 main MOS-FET conduction period than with the curve chart of the relation of the 1st VD.

The explanation of symbol

1: the 1 main MOS-FET (the 1st switch element)

2: the 2 main MOS-FET (the 2nd switch element)

3: DC power supply

4: the current resonance capacitor

5: transformer

5a: elementary winding

5b: first secondary winding

5c: second subprime winding

5d: leakage inductance (current resonance inductance)

5e: magnetizing inductance

5f: auxiliary winding

5g: for the third time the level winding (additional secondary winding)

5h, 5i: centre tap

6: voltage analog vibration capacitor

7,7a～7d: the 1st output rectifier diode

8: the 1 output smoothing capacitors

9: the 1 rectifier smoothing circuits

10,11: the 1 dc output end

12: the 1 output voltage detecting circuits

13: photoelectrical coupler

13a: luminescence unit

13b: photosensitive unit

14: main control circuit

15,15a, 15b: the 2nd output rectifier diode

16: the 2 output smoothing capacitors

17: the 2 rectifier smoothing circuits

18,19: the 2 dc output end

20: the auxiliary rectifier diode

21: auxiliary smmothing capacitor

22: the auxiliary rectifier smoothing circuit

23: starting resistance

24: rectifier diode

25: smmothing capacitor

26: copped wave MOS-FET

27: fly-wheel diode

28: filter choke coil

29: filter capacitor

30: buck circuit

31: control circuit of chopping

32: oscillating circuit

33: inverter

Dead Time added circuit in 34: the 1

35: low distolateral buffer amplifier

Dead Time added circuit in 36: the 2

37: level-conversion circuit

38: high distolateral buffer amplifier

40: output control MOS-FET (output control switch element)

41: output control circuit

42: voltage-change detecting circuit

43: the 2 output voltage detecting circuits

44:PWM control circuit (Drive and Control Circuit)

The 45:RS trigger

46: drive circuit

47: the 3 output rectifier diodes

48: the 3 output smoothing capacitors

49: the 3 rectifier smoothing circuits (additional rectifier smoothing circuit)

50: additional output control MOS-FET (additional switch element)

51,52: the 3 dc output end

53: additional control circuit

54: the 2 output control MOS-FET

55: the 2 output control circuits

56a, 56b: voltage detecting diode

The 57:D trigger

58a, 58b: the 2nd voltage detecting diode

59,60: resistance

61: voltage stabilizing didoe

62,63: divider resistance

64: parallel regulator

65,66: resistance

67: phase place correction capacitor

68: photoelectrical coupler

68a: luminescence unit

68b: photosensitive unit

69: rectifier diode

70: smmothing capacitor

71,72: divider resistance

73: diode

74: detect with transistor (detect and use switch element)

75: discharge resistance

76: comparator

77: integrating condenser

78: charging resistance

79: the discharge diode

80: electric current brownout resistance

The 81:NPN transistor

The 82:PNP transistor

83: biasing resistor

84: output resistance

85: the 2 voltage-change detecting circuits

86: the 3 output voltage detecting circuits

87: the 2PWM control circuits

88: the 2 drive circuits

89: photoelectrical coupler

89a: luminescence unit

89b: photosensitive unit

90: the 2 current resonance capacitors

91: the 2 voltage analog vibration capacitors

92: base resistance

100: choke

101: the regeneration diode

102: holding circuit

103: rectifier diode

104: smmothing capacitor

105,106: divider resistance

107: the level translation transistor

108: charging resistance

109: discharge resistance

110: keep using capacitor

111: postpone to drive and use transistor

Embodiment

Below, based on Fig. 1～Figure 34 the 1st of multi-output current-resonant type DC-DC converter of the present invention～the 17th example is described.In Fig. 1～Figure 34, the identical number of mark omits its explanation on the part identical with position essence shown in Figure 35.

The multi-output current-resonant type DC-DC converter of expression the present invention the 1st example shown in Figure 1 has omitted buck circuit shown in Figure 35 (30) and control circuit of chopping (31), between the negative electrode and the 2nd output smoothing capacitor (16) of the 2nd output rectifier diode (15) that constitutes the 2nd rectifier smoothing circuit (17), connect the output control MOS-FET (40) of conduct output control with switch element, at the 2nd dc output end (18,19) and between output control the grid, the voltage V according to the 2nd auxiliary smmothing capacitor (16) is set with MOS-FET (40) _O2The control output control output control circuit (41) of the break-make of MOS-FET (40).Output control is carried out on-off action with MOS-FET (40) synchronously and with same switching frequency with the conduction period of the 1st main MOS-FET (1).In addition, main control circuit (14) is when fixing the conduction period of the 1st main MOS-FET (1), according to the output voltage V of the 1st rectifier smoothing circuit (9) _O1The conduction period of the 2nd main MOS-FET (2) is changed, control the conducting duty ratio of the 1st main MOS-FET (1).

As shown in Figure 2, input control circuit (41) detects the voltage V of generation in the second subprime winding (5c) of transformer (5) by when the conducting of the 1st main MOS-FET (1) _T22Voltage-change detecting circuit (42), detect the voltage V of the 2nd output smoothing capacitor (16) _O2, export the error signal V that it detects the reference voltage of voltage and regulation the 2nd output voltage values _E2The 2nd output voltage detecting circuit (43), by the detection signal V of voltage-change detecting circuit (42) _TDDrive, and output has the error signal V based on the 2nd output voltage detecting circuit (43) _E2The pulse sequence signal V of the duty ratio of being controlled _PTPwm control circuit (44), by the detection signal V of voltage-change detecting circuit (42) _TDBe provided with and by the pulse sequence signal V of pwm control circuit (44) _PTThe rest-set flip-flop that resets (45), on the grid of output control, provide actuating signal V with MOS-FET (40) by the output signal of rest-set flip-flop (45) _S2Drive circuit (46) constitute.Other structure is identical with multi-output current-resonant type DC-DC converter in the past shown in Figure 35.

After the 1st main MOS-FET (1) switches to conducting, when the elementary winding (5a) of transformer (5) is gone up generation voltage, induced voltage V in second subprime winding (5c) _T22The voltage V of induction in the second subprime winding (5c) of transformer (5) _T22When being input to the 2nd rectifier smoothing circuit (17), be input to the voltage-change detecting circuit (42) in the output control circuit (41).At this moment, the detection signal V that provides high voltage (H) level to the set terminal (S) and the pwm control circuit (44) of rest-set flip-flop (45) from voltage-change detecting circuit (42) _TD, when rest-set flip-flop (45) is set, drive pwm control circuit (44).Therefore, through overdrive circuit (46), output control is provided the actuating signal V of high voltage (H) level from the lead-out terminal (Q) of rest-set flip-flop (45) with the grid of MOS-FET (40) _S2, make output control MOS-FET (40) conducting.Thus, export rectifier diode (15) through the 2nd of the 2nd rectifier smoothing circuit (17), in the 2nd output smoothing capacitor (16), flow through electric current, the voltage V of the 2nd output smoothing capacitor (16) from the second subprime winding (5c) of transformer (5) _O2Rise.

After output control becomes conducting with MOS-FET (40), because the voltage V of the second subprime winding (5c) of transformer (5) _T22Be clamped on the voltage V of the 2nd output smoothing capacitor (16) _O2Therefore, the voltage that has deducted the turn ratio part voltage of elementary winding (5a) and second subprime winding (5c) from the leakage inductance (5d) that is applied to transformer (5) and the voltage on the magnetizing inductance (5e) is applied on the leakage inductance (5d).Have in the circuit of Fig. 1 of transformer (5) of leakage inductance (5d) in use, can absorb switch or because the noise that other reason takes place by the leakage inductance (5d) of transformer (5).Then, when output control is had no progeny with MOS-FET (40) pass, owing to discharge the voltage clamp of the second subprime winding (5C) of transformer (5), therefore in first secondary winding (5b) of transformer (5), be clamped on the voltage V of the 1st output smoothing capacitor (8) _O1Common voltage.

Thereby, in the multi-output current-resonant type DC-DC converter of Fig. 1, in the conduction period of the 1st main MOS-FET (1), in the 2nd output rectifier diode (15), flow through electric current I _D2, close to have no progeny to export in the rectifier diode (7) with MOS-FET (40) in output control and flow through electric current I the 1st _D1In addition, as the 1st and the 2nd VD V _O1, V _O2Difference hour, according to the pulsating voltage of the 1st output smoothing capacitor (8) and the 1st output smoothing capacitor (16), flow through electric current I simultaneously at the 1st and the 2nd output rectifier diode (7,15) respectively sometimes _D1, I _D2The voltage V between expression drain electrode-source electrode of the 2nd main MOS-FET (2) at this moment in Fig. 3 (A)～(G) respectively _Q2, drain electrode-source current I _Q2, the 1st main MOS-FET (1) drain electrode-source electrode between voltage V _Q1, drain electrode-source current I _Q1, the electric current I that flows through in the 1st output rectifier diode (7) _D1, the electric current I that flows through in the 2nd output rectifier diode (15) _D2And the current resonance voltage V of the two ends generation of capacitor (4) _C2Each waveform.

On the other hand, the voltage V of the 2nd output smoothing capacitor (16) _O2Detect its detection signal and the error signal V that stipulates the 2nd output voltage values reference signal by the 2nd output voltage detecting circuit (43) in the output control circuit (41) _E2Be input to pwm control circuit (44).Pwm control circuit (44) is by the detection signal V of high voltage (H) level that provides from voltage-change detecting circuit (42) _TDDrive, according to the error signal V of the 2nd output voltage detecting circuit (43) _E2Voltage level control impuls sequence signal V _PTDuty ratio.That is, as the voltage V of the 2nd output smoothing capacitor (16) _O2When higher, from the little pulse sequence signal V of pwm control circuit (44) output duty cycle than reference voltage _PTOtherwise, as the voltage V of the 2nd output smoothing capacitor (16) _O2When lower, from the big pulse sequence signal V of pwm control circuit (44) output duty cycle than reference voltage _PTPulse sequence signal V by the pwm control circuit (44) of the reseting terminal that is provided to rest-set flip-flop (45) (R) _PT, rest-set flip-flop (45) is resetted.Thereby, as the 2nd VD V of the 2nd rectifier smoothing circuit (17) _O2When higher than set point, from pwm control circuit (44) the little pulse sequence signal V of duty ratio _PTBe provided to the reseting terminal (R) of rest-set flip-flop (45), through overdrive circuit (46), provide the actuating signal V of narrow pulses width with the grid of MOS-FET (40) to output control from the lead-out terminal (Q) of rest-set flip-flop (45) _S2

Thus because output control shortens with conduction period of MOS-FET (40), in the 2nd output smoothing capacitor (16), flow through electric current during shorten so voltage V of the 2nd output smoothing capacitor (16) _O2Reduce.Otherwise, as the 2nd VD V of the 2nd rectifier smoothing circuit (17) _O2When lower, provide duty ratio big pulse sequence signal V from the reseting terminal (R) of pwm control circuit (44) to rest-set flip-flop (45) than set point _PT, control the actuating signal V that the broad pulse width is provided with the grid of MOS-FET (40) to output through overdrive circuit (46) from the lead-out terminal (Q) of rest-set flip-flop (45) _S2Thus because output control is elongated with the ON time of MOS-FET (40), in the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17), flow through electric current during prolong the therefore voltage V of the 2nd output smoothing capacitor (16) _O2Rise.Like this, according to the output voltage V of the 2nd rectifier smoothing circuit (17) _O2Control output is controlled with the conduction period of the conduction period of MOS-FET (40) and the 1st main MOS-FET (1) synchronous, can take out the 2nd roughly certain VD V from the 2nd dc output end (18,19) _O2In addition, because roughly the same, therefore omit the explanation of other elemental motion of multi-output current-resonant type DC-DC converter shown in Figure 1 with the action of multi-output current-resonant type DC-DC converter in the past shown in Figure 35.

According to the resonance frequency decision of the leakage inductance (5d) of current resonance capacitor (4) and transformer (5) decision from the primary side of transformer (5) during the primary side supply capability, even it is be connected the load change of the 1st dc output end (10,11), also almost constant during the primary side supply capability from the primary side of transformer (5).Thereby, can with the change of the load of the 1st dc output end (10,11) of first secondary winding (5b) side that is connected transformer (5) irrespectively, take out needed direct current power from the 2nd dc output end (18,19).In addition, because it is synchronous with the conduction period of the 1st main MOS-FET (1), make output control carry out on-off action with MOS-FET (40), be controlled at flow through in the 2nd output smoothing capacitor (16) electric current during, so can be according to the voltage V of the 2nd smmothing capacitor (19) _O2, by the break-make of output control circuit (41) control output control with MOS-FET (40), can be with the 2nd direct current output V of High Accuracy Control from the 2nd rectifier smoothing circuit (17) output _O2Thereby, owing to can directly control from the 2nd VD V of the 2nd rectifier smoothing circuit (17) output with the on-off action of MOS-FET (40) by output control _O2, so the power converter loss is few, can just add output control in addition and just can obtain the 2nd high VD V of stability with the so easy circuit change of MOS-FET (40) in the 2nd rectifier smoothing circuit (17) _O2, therefore can realize cheapness, power converter efficient height and can obtain the multi-output current-resonant type DC-DC converter that high-precision direct current is exported.

Multi-output current-resonant type DC-DC converter shown in Figure 1 can change.For example, the multi-output current-resonant type DC-DC converter of the present invention's the 2nd example shown in Figure 4 possesses: the winding (5g) of level for the third time that is arranged on the additional secondary winding of conduct on the transformer shown in Figure 1 (5), is connected with level winding (5g) for the third time and as the 3rd rectifier smoothing circuit (49) of the rectifier smoothing circuit that adds that constitutes by the 3rd output rectifier diode (47) and the 3rd output smoothing capacitor (48), additional output control MOS-FET (50) as the additional switch element between negative electrode that is connected the 3rd output rectifier diode (47) and the 3rd output smoothing capacitor (48), based on being connected the 3rd dc output end (51,52) and additional output control with the voltage V of the 3rd output smoothing capacitor (48) between the MOS-FET (50) _O3Control the additional control control circuit (53) of additional output control with the break-make of MOS-FET (5).The level winding (5g) for the third time of transformer (5) is connected with the 1st and second subprime winding (5b, 5c) reversed polarity, and additional output control is synchronous with the conduction period of the 2nd main MOS-FET (2) with MOS-FET (50), carries out on-off action.Other structure and action are identical with multi-output current-resonant type DC-DC converter shown in Figure 1.

In the multi-output current-resonant type DC-DC converter of the present invention's the 2nd example, because it is identical with Fig. 1, even load change, also almost constant during the primary side supply capability from the primary side of transformer (5), therefore to export out the load change of terminal (10,11) irrelevant with being connected the 1st direct current, can be from the 2nd and the 3rd dc output end (18,19; 51,52) take out the 2nd and the 3rd stable VD V respectively individually _O2, V _O3Thereby, export out a certain side of diode (7,15,47) or both sides' polarity by the 1st～for the third time grade of winding (5b, 5c, 5g) that changes transformer (5) and the 1st～the 3rd rectification that constitutes the 1st～the 3rd rectifier smoothing circuit (9,17,49), the control fiducial values of the control circuit (53) that perhaps changes output control circuit (41) and add etc. can realize taking place polarity and magnitude of voltage three different VD V mutually _O1, V _O2, V _O3Multi-output current-resonant type DC-DC converter.In addition, therefore because the polarity of the level winding (5g) for the third time of transformer (5) is opposite with the 1st and second subprime winding (5b, 5c), can obtain being applied to when the 2nd main MOS-FET (2) conducting leakage inductance (5d) of transformer (5) and the turn ratio burning voltage partly of the voltage on the magnetizing inductance (5e) from grade winding (5g) for the third time.

The multi-output current-resonant type DC-DC converter of the present invention's the 3rd example shown in Figure 5 changes to basis to the control mode of main control circuit (14) and controls the 1st and the 2nd main MOS-FET (1 from the change of the input voltage E of DC power supply (3), the mode of break-make 2), omit the 1st output voltage detecting circuit (12) shown in Figure 4 and photoelectrical coupler (13), between the negative electrode of the 1st output rectifier diode (7) shown in Figure 4 and the 1st output smoothing capacitor (8), is connected the 2nd output and controls usefulness MOS-FET (54), at the 1st dc output end (10,11) and between the grid of the 2nd output control with MOS-FET (54), the voltage V according to the 1st output smoothing capacitor (8) is set _O1Control 2nd output control circuit (55) of the 2nd output control, output control shown in Figure 4 is exported between the anode of rectifier diode (15) with the second subprime winding (54) and the 2nd that the link position of MOS-FET (40) is altered to transformer (5) with the break-make of MOS-FET (54).Main control circuit shown in Figure 5 (14) is fixed the conduction period of the 1st main MOS-FET (1), according to change from the input voltage E of DC power supply (3), by making the conduction period variation of the 2nd main MOS-FET (2), control the conducting duty ratio of the 1st main MOS-FET (1).Other structure is identical with multi-output current-resonant type DC-DC converter shown in Figure 4.In addition, remove voltage V according to the 1st output smoothing capacitor (8) _O1, control the break-make of the 2nd output control, the 1st VD V between the 1st dc output end (10,11) with MOS-FET (54) _O1Be controlled to be beyond certain this point, the action of the action of multi-output current-resonant type DC-DC converter shown in Figure 5 and multi-output current-resonant type DC-DC converter shown in Figure 1 is roughly the same.

In Fig. 5, because even load change is also almost constant during the primary side supply capability from the primary side of transformer (5), therefore by by main control circuit (14) according to the break-make of controlling the 1st and the 2nd main MOS-FET (1,2) from the change of the input voltage E of DC power supply (3), can be the voltage control of the elementary winding (5a) that is applied to transformer (5) for necessarily.Thereby, by output control is set in the 1st of primary side～the 3rd rectifier smoothing circuit (9,17,49) whole with MOS-FET (54,40,50), according to the output voltage V of the 1st～the 3rd rectifier smoothing circuit (9,17,49) _O1, V _O2, V _O3, the break-make with MOS-FET (54,40,50) is controlled in each output of control individually, can be from the 1st～the 3rd dc output end (10,11; 18,19; 51,52) obtain magnitude of voltage the 1st～the 3rd different VD V mutually _O1, V _O2, V _O3In addition, identical owing to can all constituting the dc output circuit of primary side, therefore when the kind that can further reduce parts reduces manufacturing cost, also have the advantage that improves the interchangeability in the maintenance.

The multi-output current-resonant type DC-DC converter of the present invention's the 4th example shown in Figure 6 is altered to the link position of the output of Fig. 4 control with MOS-FET (40) on the second subprime winding (5c) and the earth connection between the 2nd output smoothing capacitor (16) of transformer (5), make the opposite polarity while of level winding (5g) for the third time with transformer shown in Figure 4 (5), the link position of the 3rd output rectifier diode (47) is altered on grade winding (5g) for the third time and the earth connection between the 3rd output smoothing capacitor (48) of transformer (5).Other structure is identical with the multi-output current-resonant type DC-DC converter of Fig. 4, and the action of the action of the multi-output current-resonant type DC-DC converter of Fig. 6 and the multi-output current-resonant type DC-DC converter of Fig. 1 is roughly the same.

Even owing to also be load change among Fig. 6, also almost constant during the primary side supply capability from the primary side of transformer (5), even therefore the polarity of the level winding (5g) for the third time of change transformer (5) or the 3rd output rectifier diode (47) and output control also can obtain effect identical with Fig. 4 and effect with the link position of MOS-FET (40).

In the 1st～the 4th example, use the halfwave rectifier type that constitutes by a rectification output diode (7,15,47) and output smoothing capacitor (8,16,48) to constitute each rectifier smoothing circuit (9,17,49), and also can be with formations such as two ripple rectification types or full-wave rectification bridge types.For example, the multi-output current-resonant type DC-DC converter of the present invention's the 5th example shown in Figure 7 is at each secondary winding (5b of transformer shown in Figure 1 (5), centre tap (5h is set 5c), 5i), at each secondary winding (5b, two ends 5c) connect a pair of output rectifier diode (7a, 7b:15a, 15b), at each a pair of output rectifier diode (7a, 7b:15a, tie point 15b) and each secondary winding (5b, centre tap (5h 5c), 5i), connect output smoothing capacitor (8,16), each rectifier smoothing circuit (9 of Fig. 4,17) change to the structure of two ripple rectification types, constituting the 2nd output rectifier diode (15a of the 2nd rectifier smoothing circuit (17), between anode 15b) and the output control circuit (41), the voltage V of the second subprime winding (5c) of joint detection transformer (5) _T22A pair of voltage detecting with diode (56a, 56b).In addition, in main control circuit shown in Figure 7 (14), as shown in Figure 8, d type flip flop (57) is set, the signal input terminal of d type flip flop (57) (D) is connected to the lead-out terminal of oscillator (32), reversed-phase output (Q) is connected to the input terminal that the 2nd Dead Time adds circuit (36), noninverting lead-out terminal (Q) is connected to the input terminal that the 1st Dead Time adds circuit (34).Thus, because at every turn from oscillator (32) to the error signal V of the signal input terminal (D) of d type flip flop (57) input according to the 1st output voltage detecting circuit (12) _E1The pulse signal V of voltage level frequency change _PL, switch from reversed-phase output and (Q) and the voltage level export respectively of noninverting lead-out terminal (Q), therefore can make the 1st and the 2nd main MOS-FET (1,2) break-make alternately with 50% duty ratio.Other structure is identical with multi-output current-resonant type DC-DC converter shown in Figure 1.

In Fig. 7, after not shown mains switch was connected, the voltage E of DC power supply (3) was applied on the auxiliary smmothing capacitor (21) of auxiliary rectifier smoothing circuit (22) through starting resistance (23), will assist smmothing capacitor (21) charging.After the charging voltage of auxiliary smmothing capacitor (21) reached the starting voltage of main control circuit (14), main control circuit (14) began action.At this moment, provide the 1st and the 2nd drive signal V to each grid of the 1st and the 2nd main MOS-FET (1,2) respectively from main control circuit (14) _G1, V _G2, the 1st and the 2nd main MOS-FET (1,2) begins on-off action.When the 1st main MOS-FET (1) conducting, flow through electric current I in the path with capacitor (4), the leakage inductance (5d) of transformer (5), elementary winding (5a), the 1st main MOS-FET (1) and DC power supply (3) at DC power supply (3), current resonance _Q1

At this moment, be subjected to first secondary winding (5b) at transformer (5), a side the 1st influence of exporting first secondary current that flows through in the path of rectifier diode (7a) and the 1st output smoothing capacitor (8), in the path of current resonance, flow through the 1st load current with capacitor (4), the leakage inductance (5d) of transformer (5), elementary winding (5a) and the 1st main MOS-FET (1).In addition, be subjected to the influence of the second subprime electric current that flows through in the path of second subprime winding (5c), a side's the 2nd rectification output rectifier diode (15a) of transformer (5) and the 2nd output smoothing capacitor (16), in the path of current resonance, flow through the 2nd load current with capacitor (4), the leakage inductance (5d) of transformer (5), elementary winding (5a) and the 1st main MOS-FET (1).And then, in the path of current resonance, flow through exciting current with leakage inductance (5d), magnetizing inductance (5e) and the 1st main MOS-FET (1) of capacitor (4), transformer (5).Flow through the electric current I of the 1st main MOS-FET (1) _Q1Become the resultant current of the 1st load current, the 2nd load current and exciting current.The the 1st and the 2nd load current becomes the sinuous resonance current that has by the resonance frequency of leakage inductance (5d) decision of the electrostatic capacitance of current resonance capacitor (4) and transformer (5).Exciting current becomes and has by the combination inductance of the leakage inductance (5d) of transformer (5) and magnetizing inductance (5e) and the current resonance resonance current with the resonance frequency of the electrostatic capacitance decision of capacitor (4), and because its resonance frequency is lower than the conduction period of the 1st main MOS-FET (1), therefore being observed with the part of sine wave is the wavy electric current of triangle of hypotenuse.

Then,, the 1st main MOS-FET (1) has no progeny when closing, and identical by the energy of in transformer (5), storing by above-mentioned exciting current with the circuit of Figure 35, the voltage analog vibration takes place.Thereby, in this period, can switch to the zero voltage switch (ZVS) of the 2nd main MOS-FET (2) of conducting.

After the energy by the exciting current generation in being stored in transformer (5) discharges and finishes, by being stored in current resonance with the energy in capacitor (4), flow through electric current in capacitor (4), the 2nd main MOS-FET (2), elementary winding (5a), leakage inductance (5d) and the path of current resonance with capacitor (4) at current resonance.Thereby, first secondary winding (5b) through transformer (5), at the opposing party's the 1st output rectifier diode (7b), flow through the 1st load current in the path of the 1st output smoothing capacitor (8), second subprime winding (5c) through transformer (5), at the opposing party's the 2nd output rectifier diode (15b), flow through the 2nd load current in the path of the 2nd output smoothing capacitor (16), and then, at current resonance capacitor (4), the 2nd main MOS-FET (2), the magnetizing inductance (5e) of transformer (5), in leakage inductance (5d) and current resonance the path with capacitor (4), along with conduction period of the 1st main MOS-FET (1) in opposite direction, flow through the exciting current of circulation in transformer (5), discharge the energy that is stored in the current resonance usefulness capacitor (4).Exciting current is the resonance current by the resonance frequency of the electrostatic capacitance decision of the combination inductance of leakage inductance of transformer (5) (5d) and magnetizing inductance (5e) and current resonance usefulness capacitor (4), and owing to the resonance frequency of comparing with the conduction period of the 2nd main MOS-FET (2) is low, therefore being observed with the part of sine wave is the wavy electric current of triangle of hypotenuse.

Fig. 9 (A) and the drain electrode-voltage between source electrodes V that (B) represents the 1st and the 2nd main MOS-FET (1,2) respectively _Q1, V _Q2, the electric current I that in each main MOS-FET (1,2), flows through _Q1, I _Q2With the electric current I that in the 1st rectifier smoothing circuit (9), flows through _D1When the input voltage E that supplies with from DC power supply (3) is low and when high, fix the Dead Time of the 1st and the 2nd main MOS-FET (1,2), and to the 1st and the 2nd drive signal V _G1, V _G2Carry out FREQUENCY CONTROL, the duty ratio with 50% can obtain Fig. 9 (A) and waveform (B) when making the mutual break-make of the 1st and the 2nd main MOS-FET (1,2).That is, Fig. 9 (A) and (B) expression by according to the variation of input voltage E, to the 1st and the 2nd drive signal V _G1, V _G2Carry out FREQUENCY CONTROL, change the conduction period of the 1st and the 2nd main MOS-FET (1,2), make the state of the exciting current variation of the transformer (5) that in magnetizing inductance (5e), leakage inductance (5d) and current resonance the path with capacitor (4) of current resonance, flows through with capacitor (4), the 2nd main MOS-FET (2), transformer (5).Thus, can adjust the voltage V of current resonance with capacitor (4) two ends _C2, control the 1st VD V _O1Fig. 9 (C) and (D) the voltage V when representing respectively that load is light and heavy _Q1, V _Q2And electric current I _Q1, I _Q2, I _D1Waveform.That is, in Fig. 9 of light-load state (C), flow through the electric current I of the 1st and the 2nd main MOS-FET (1,2) _Q1, I _Q2Be about triangular waveform, flow through resonance current hardly, and in Fig. 9 of heavy duty state (D), flow through the electric current I of the 1st and the 2nd main MOS-FET (1,2) as load current _Q1, I _Q2Comprise being the part that sinusoidal wave shape changes, flow through the resonance current that is equivalent to load current.In addition, if the drain electrode-voltage between source electrodes V of the 1st and the 2nd main MOS-FET (1,2) Fig. 9 (C) and (D) _Q1With V _Q2Compare, then can understand change, the almost constant situation of switching frequency of the 1st and the 2nd main MOS-FET (1,2) for load.

When the 1st main MOS-FET (1) conducting, in the elementary winding (5a) of transformer (5), take place to pass through second subprime winding (5c) in the voltage, voltage V takes place in the negative electrode of side's voltage detecting usefulness diode (56a) _T22In addition, when the conducting of the 2nd main MOS-FET (2), in the elementary winding (5a) of transformer (5), take place in the voltage, pass through second subprime winding (5c) voltage V takes place in the negative electrode of the opposing party's voltage detecting usefulness diode (56b) _T22The voltage V that in the negative electrode of a pair of voltage detecting, takes place with diode (56a, 56b) _T22Be input to the voltage-change detecting circuit (42) in the output control circuit (41), the detection signal V that provides high voltage (H) level to the set terminal (S) and the pwm control circuit (44) of rest-set flip-flop (45) from voltage-change detecting circuit (42) _TD, in rest-set flip-flop (45) set, drive pwm control circuit (44).

For this reason, through overdrive circuit (46) output control is provided the actuating signal V of high voltage (H) level with the grid of MOS-FET (40) from the lead-out terminal (Q) of rest-set flip-flop (45) _S2, output control MOS-FET (40) conducting.Thus, when the each mutual conducting of the 1st and the 2nd main MOS-FET (1,2), export a side (15a) or the opposing party (15b) of rectifier diode through the 2nd of the 2nd rectifier smoothing circuit (17) from the second subprime winding (5c) of transformer (5), in the 2nd output smoothing capacitor (16), flow through electric current, the voltage V of the 2nd output smoothing capacitor (16) _O2Rise.

After output control switched to conducting with MOS-FET (40), the upside of the second subprime winding (5c) of transformer (5) or the every half period of voltage of downside were clamped on the voltage V of the 2nd output smoothing capacitor (6) of the 2nd rectifier smoothing circuit (17) _O2Thereby, at the voltage of the turn ratio part voltage that applies the upside that deducts elementary winding (5a) and second subprime winding (5c) from the leakage inductance (5d) that is applied to transformer (5) and the voltage on the magnetizing inductance (5e) or downside on the leakage inductance (5d).In the circuit of Fig. 7,, therefore can absorb the unwanted voltage composition of output voltage by the leakage inductance (5d) of transformer (5) owing to use transformer (5) with leakage inductance (5d).

Then, output control switches to after the shutoff with MOS-FET (40), because the upside of the second subprime winding (5c) of transformer (5) or the voltage clamp of downside discharge in every half period, therefore at the upside or the downside of first secondary winding (5b) of transformer (5), be clamped on the voltage V of the 1st output smoothing capacitor (8) of the 1st rectifier smoothing circuit (9) in every half period _O1Common voltage.Thereby, in circuit shown in Figure 7, in the conduction period of the 1st main MOS-FET (1), the 2nd rectifier smoothing circuit (17) the 2nd output rectifier diode a side (15a) in flow through electric current I _D2, after output control has been turn-offed with MOS-FET (40), in the 1st of the 1st rectifier smoothing circuit (9) is exported the side (7a) of rectifier diode, flow through electric current I _D1In addition, in the conduction period of the 2nd main MOS-FET (2), the 2nd rectifier smoothing circuit (17) the 2nd output rectifier diode the opposing party (15b) in flow through electric current I _D2, after output control has been turn-offed with MOS-FET (40), in the 1st of the 1st rectifier smoothing circuit (9) is exported the opposing party (7b) of rectifier diode, flow through electric current I _D1

And then, as the 1st and the 2nd VD V _O1, V _O2Difference hour, pulsating voltage according to the 2nd output smoothing capacitor (16) of the 1st output smoothing capacitor (8) of the 1st rectifier smoothing circuit (9) and the 2nd rectifier smoothing circuit (17), at every half period, in exporting the opposing party (7b, 15b) of rectifier diode, the side (7a, 15a) or the 1st and the 2nd of the 1st and the 2nd output rectifier diode flows through electric current I sometimes simultaneously _D1, I _D2Situation.Drain electrode-voltage between source electrodes the V that in Figure 10 (A)～(F), represents the 1st main MOS-FET (1) at this moment respectively _Q1, the 2nd main MOS-FET (2) drain electrode-source electrode between voltage V _Q2, the electric current I that in the 1st main MOS-FET (1), flows through _Q1, the electric current I that in the 2nd main MOS-FET (2), flows through _Q2, the electric current I that in the 1st output rectifier diode (7a, 7b), flows through _D1And the electric current I that in the 2nd output rectifier diode (15a, 15b), flows through _D2Each waveform.

On the other hand, detect the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) by the 2nd output voltage detecting circuit (43) in the output control circuit (41) _O2, the error signal V of the reference voltage of its detection signal and regulation the 2nd output voltage values _E2Be imported into pwm control circuit (44).Detection signal V by high voltage (H) level that provides from voltage-change detecting circuit (42) _TDDrive pwm control circuit (44), based on the error signal V of the 2nd output voltage detecting circuit (43) _E2The pulse sequence signal V that exported of voltage level control _PTDuty ratio.That is, as the voltage V of the 2nd output smoothing capacitor (16) _O2When higher, from the little pulse sequence signal V of pwm control circuit (44) output duty cycle than reference voltage _PT, as the voltage V of the 2nd output smoothing capacitor (16) _O2When lower, from the big pulse sequence signal V of pwm control circuit (44) output duty cycle than reference voltage _PTPulse sequence signal V from pwm control circuit (44) output _PTOffer the reseting terminal (R) of rest-set flip-flop (45), the rest-set flip-flop that resets (45).Thereby, as the 2nd VD V of the 2nd rectifier smoothing circuit (17) _O2When higher, provide duty ratio little pulse sequence signal V from the reseting terminal (R) of pwm control circuit (44) to rest-set flip-flop (45) than set point _PT, through overdrive circuit (46), provide the actuating signal V of narrow pulse width with the grid of MOS-FET (40) to output control from the lead-out terminal (Q) of rest-set flip-flop (45) _S2Thus because output control shortens with conduction period of MOS-FET (40), therefore shortening in the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17), flow through electric current during, the voltage V of the 2nd output smoothing capacitor (16) _O2Reduce.

In addition, as the 2nd VD V of the 2nd rectifier smoothing circuit (17) _O2When lower, provide duty ratio big pulse sequence signal V from the reseting terminal (Q) of pwm control circuit (44) to rest-set flip-flop (45) than set point _PT, through overdrive circuit (46), provide the actuating signal V of broad pulse width with the grid of MOS-FET (40) to output control from the lead-out terminal (Q) of rest-set flip-flop (45) _S2Thus because output control is long with the conduction period of MOS-FET (40), therefore prolongation in the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17), flow through electric current during, the voltage V of the 2nd output smoothing capacitor (16) _O2Rise.Like this, can be based on the output voltage V of the 2nd rectifier smoothing circuit (17) _O2, synchronous with the switching frequency of the 1st and the 2nd main MOS-FET (1,2) of primary side, control output control is exported roughly the 2nd VD V of certain value with the conduction period of MOS-FET (40) from the 2nd dc output end (18,19) _O2

In Fig. 7, owing to the change for load, the switching frequency of the 1st and the 2nd main MOS-FET (1,2) is almost constant, and is therefore also almost constant during the primary side supply capability from the primary side of transformer (5).Thereby, the change of going up load with the 1st dc output end (10,11) of first secondary winding (5b) side that is connected transformer (5) is irrelevant, can take out needed direct current power from the 2nd dc output end (18,19) through the 2nd rectifier smoothing circuit (17) on the second subprime winding (5c) that is connected transformer (5).In addition, make output control with MOS-FET (40) break-make synchronously by switching frequency with the 1st and the 2nd main MOS-FET (1,2), be controlled at flow through in the 2nd output smoothing capacitor (16) electric current during.For this reason, by in output control circuit (41) based on the voltage V of the 2nd smmothing capacitor (16) _O2The control output control break-make of MOS-FET (40) can be with High Accuracy Control the 2nd VD V _O2Thereby, owing to can directly control the 2nd VD V with the on-off action of MOS-FET (40) by output control _O2, so power converter loss is few, in addition, just goes up at the 2nd rectifier smoothing circuit (17) and adds output control and change with the simple circuit of MOS-FET (40) and just can obtain the 2nd high VD V of stability _O2, therefore can realize obtaining the multi-output current-resonant type DC-DC converter that cheapness, power converter efficient height and high-precision direct current are exported.

The multi-output current-resonant type DC-DC converter of the present invention's the 6th example shown in Figure 11 possesses: as the winding (5g) of level for the third time that is arranged on the additional secondary winding on the transformer shown in Figure 7 (5); Be connected for the third time on the level winding (5g), as the 3rd rectifier smoothing circuit (49) of the additional rectifier smoothing circuit that constitutes by the 3rd output rectifier diode (47) and the 3rd output smoothing capacitor (48); Additional output control MOS-FET (50) as negative electrode that is connected the 3rd output rectifier diode (47) and the extra switch element between the 3rd output smoothing capacitor (48); Be arranged between the 3rd dc output end (51,52) and the grid of additional output control, based on the voltage V of the 3rd output smoothing capacitor (48) with MOS-FET (50) _O3, the additional output control of the control additional control circuit (53) of the break-make of MOS-FET (50).The internal structure of additional control circuit (53) is identical with the internal structure of output control circuit (41) shown in Figure 2, and other structure is identical with multi-output current-resonant type DC-DC converter shown in Figure 7.

In the multi-output current-resonant type DC-DC converter of Figure 11, owing to use the halfwave rectifier type that constitutes by an output rectifier diode (47) and an output smoothing capacitor (48) to constitute the 3rd rectifier smoothing circuit (49), therefore synchronous with the conduction period of the 1st main MOS-FET (1), make additional output control with MOS-FET (50) on-off action, export the 3rd VD V through the 3rd dc output end (51,52) from the 3rd rectifier smoothing circuit (49) _O3Detect the voltage V of the 3rd output smoothing capacitor (48) of the 3rd rectifier smoothing circuit (49) by additional control circuit (53) _O3, detecting the error signal of the reference voltage of voltage and regulation the 3rd output voltage values according to this, additional output control uses MOS-FET (50) synchronous with the switching frequency of the 1st main MOS-FET (1), carries out pulse-width modulation (PWM).Thus, stable from the 3rd VD V of the 3rd rectifier smoothing circuit (49) through the 3rd dc output end (51,52) output _O3The action of elemental motion beyond above-mentioned and the multi-output current-resonant type DC-DC converter of Fig. 7 is roughly the same.

In Figure 11, identical with Fig. 7, even because load change is also almost constant during the primary side supply capability from the primary side of transformer (5), therefore irrelevant with the load change that is connected the 1st dc output end (10,11), can be from the 2nd and the 3rd dc output end (18,19; 51,52) take out the 2nd and the 3rd stable VD V respectively _O2, V _O3Thereby, constitute the 1st～for the third time grade of winding (5b, 5c, 5g) of transformer (5) and the 1st～the 3rd output rectifier diode (7a, 7b of the 1st～the 3rd rectifier smoothing circuit (9,17,49) by change; 15a, 15b; 47) either party or both sides' polarity perhaps change the control fiducial value of output control circuit (41) or additional control circuit (53) etc., can realize taking place polarity or magnitude of voltage three different VD V mutually _O1, V _O2, V _O3Multi-output current-resonant type DC-DC converter.

The multi-output current-resonant type DC-DC converter of the present invention's the 7th example shown in Figure 12 is exported rectifier diode (15a to shown in Figure 11 by two the 2nd, 15b) the 2nd rectifier smoothing circuit (17) of the two ripple rectification types that constitute with one the 2nd output smoothing capacitor (16) is replaced into four the 2nd output rectifier diodes being connected by bridge-type (bridge) (15a～15d) and the 2nd rectifier smoothing circuit (17) of the full-wave rectification bridge type of one the 2nd output smoothing capacitor (16) formation, between the upper end of the second subprime winding (5c) of transformer (5) and lower end and output control circuit (41), be connected a pair of voltage detecting with diode (56a, 56b), make transformer (5) for the third time the level winding (5g) polarity opposite with polarity shown in Figure 11.In example shown in Figure 12, because the polarity of the level winding (5g) for the third time of transformer (5) is opposite with the 1st and second subprime winding (5b, 5c), therefore additional output control is carried out on-off action with MOS-FET (5) synchronously with the conduction period of the 2nd main MOS-FET (2).Other structure is identical with multi-output current-resonant type DC-DC converter shown in Figure 11.

In the multi-output current-resonant type DC-DC converter of Figure 12, (15a～15d) carries out full-wave rectification to four the 2nd output rectifier diodes that the alternating voltage that takes place at second subprime winding (5c) two ends of transformer (5) is connected by bridge-type, through output control with MOS-FET (40) and the 2nd output smoothing capacitor (16), from the 2nd dc output end (18,19) output smoothing the 2nd VD V _O2Detect the voltage V of the 2nd output smoothing capacitor (16) in the 2nd rectifier smoothing circuit (17) by output control circuit (41) _O2, according to this error signal that detects the reference voltage of voltage and regulation the 2nd output voltage values, output control is synchronous with the switching frequency of MOS-FET (40) and the 1st and the 2nd main MOSFET (1,2), carries out PWM (pulse-width modulation) control.Thus, stable from the 2nd VD V of the 2nd rectifier smoothing circuit (17) through the 2nd dc output end (18,19) output _O2

In addition, additional output control is carried out on-off action with MOS-FET (50) synchronously with the conduction period of the 2nd main MOS-FET (2), exports the 3rd VD V from the 3rd rectifier smoothing circuit (49) through the 3rd dc output end (51,52) _O3Detect the voltage V of the 3rd output smoothing capacitor (48) in the 3rd rectifier smoothing circuit (49) by additional control circuit (53) _O3, detecting the error signal of voltage and the reference voltage of regulation the 3rd output voltage values according to this, additional output control is synchronous with the switching frequency of the 1st main MOS-FET (1) with MOS-FET (50), carry out pulse-width modulation (PWM).Thus, stable from the 3rd VD V of the 3rd rectifier smoothing circuit (49) through the 3rd dc output end (51,52) output _O3The action of elemental motion beyond above-mentioned and the multi-output current-resonant type DC-DC converter of Fig. 7 is roughly the same.

In Figure 12, identical with Figure 11, even because load change, also almost constant during the primary side supply capability from the primary side of transformer (5), therefore as shown in figure 12, even the 2nd rectifier smoothing circuit (17) of two ripple rectification types is changed to the full-wave rectification bridge type, the polarity of level winding (5g) for the third time of transformer (5) is become and the 1st and the opposite polarity of second subprime winding (5b, 5c), also can obtain effect and the effect roughly the same with Figure 11.

The multi-output current-resonant type DC-DC converter of the present invention's the 8th example shown in Figure 13 is for the be connected in parallel elementary winding (5a) of transformer shown in Figure 12 (5) of the 1st main MOS-FET (1), leakage inductance (5d) and the current resonance series circuit of capacitor (4), (the 2nd rectifier smoothing circuit (17) of the full-wave rectification bridge type that 15a～15d) and one the 2nd output smoothing capacitor (16) constitute changes to the 2nd rectifier smoothing circuit (17) by the halfwave rectifier type of one the 2nd output rectifier diode (15) and one the 2nd output smoothing capacitor (16) formation four the 2nd output rectifier diodes that connected by bridge-type, on the earth connection between the second subprime winding (5c) of transformer (5) and the 2nd output smoothing capacitor (16), be connected output control, the link position of the 3rd output rectifier diode (47) that constitutes the 3rd rectifier smoothing circuit (49) shown in Figure 12 be altered on grade winding (5g) for the third time and the earth connection between the 3rd output smoothing capacitor (48) of transformer (5) with MOS-FET (40).The multi-output current-resonant type DC-DC converter of other structure and Figure 12 is roughly the same.

In the multi-output current-resonant type DC-DC converter of Figure 13, output control is carried out on-off action with MOS-FET (40) synchronously with the conduction period of the 2nd main MOS-FET (2), exports the 2nd VD V from the 2nd rectifier smoothing circuit (17) through the 2nd dc output end (18,19) _O2Detect the voltage V of the 2nd output smoothing capacitor (16) in the 2nd rectifier smoothing circuit (17) by output control circuit (41) _O2, according to the error signal of this detection voltage with the reference voltage of regulation the 2nd output voltage values, output control is carried out pulse-width modulation (PWM) control synchronously with the switching frequency of MOS-FET (40) and the 2nd main MOS-FET (2).Thus, stable from the 2nd VD V of the 2nd rectifier smoothing circuit (17) through the 2nd dc output end (18,19) output _O2On the other hand, additional output control is carried out on-off action with MOS-FET (50) synchronously with the conduction period of the 1st main MOS-FET (1), exports the 3rd direct current output V from the 3rd rectifier smoothing circuit (49) through the 3rd dc output end (51,52) _O3Detect the voltage V of the 3rd output smoothing capacitor (48) in the 3rd rectifier smoothing circuit (49) by additional control circuit (53) _O3, detecting the error signal of the reference voltage of voltage and regulation the 3rd output voltage values according to this, additional output control is carried out pulse-width modulation (PWM) synchronously with the switching frequency of MOS-FET (50) and the 1st main MOS-FET (1).Thus, stable from the 3rd VD V of the 3rd rectifier smoothing circuit (49) through the 3rd dc output end (51,52) output _O3The action of elemental motion beyond above-mentioned and the multi-output current-resonant type DC-DC converter of Fig. 7 is roughly the same.

In Figure 13, identical with Figure 12, even because load change, also almost constant during the primary side supply capability from the primary side of transformer (5), even therefore as shown in figure 13 the 2nd rectifier smoothing circuit (17) of full-wave rectification bridge type is changed to the halfwave rectifier type, the change output control link position of MOS-FET (40), perhaps change constitutes the link position of the 3rd output rectifier diode (47) of the 3rd rectifier smoothing circuit (49), also can obtain effect and the effect roughly the same with Figure 12.

The multi-output current-resonant type DC-DC converter of the present invention's the 9th example shown in Figure 14 omits the second subprime winding (5c) of the transformer with centre tap (5i) (5) shown in Figure 7, between the centre tap (5h) and lower end of first secondary winding (5b) of transformer (5), connection is by the 2nd rectifier smoothing circuit (17) of the halfwave rectifier type of the 2nd output rectifier diode (15) and the 2nd output smoothing capacitor (16) formation, between negative electrode and the 2nd output smoothing capacitor (16) of the 2nd output rectifier diode (15), is connected output and controls usefulness MOS-FET (40), at the 2nd dc output end (18,19) and output control with the voltage V that is provided with between the MOS-FET (40) according to the 2nd output smoothing capacitor (16) _O2The control output control output control circuit (41) of the break-make of MOS-FET (40).The multi-output current-resonant type DC-DC converter of other structure and Fig. 7 is roughly the same.

In the multi-output current-resonant type DC-DC converter of Figure 14, when the 2nd main MOS-FET (2) conducting, taking place with the lower end between the lower end of first secondary winding (5b) of transformer (5) and centre tap (5h) is positive voltage V _T22, output control MOS-FET (40) conducting.Thereby output control is carried out on-off action with MOS-FET (40) synchronously with the conduction period of the 2nd main MOS-FET (2), exports the 2nd VD V from the 2nd from rectifier smoothing circuit (17) through the 2nd dc output end (18,19) _O2Detect the voltage V of the 2nd output smoothing capacitor (16) in the 2nd rectifier smoothing circuit (17) by output control circuit (41) _O2, according to this error signal that detects the reference voltage of voltage and regulation the 2nd output voltage values, output control is synchronous with the switching frequency of the 2nd main MOSFET (2) with MOS-FET (40), modulation pulsewidth (PWM).Thus, stable from the 2nd direct voltage V of the 2nd rectifier smoothing circuit (17) through the 2nd dc output end (18,19) output _O2Action about the multi-output current-resonant type DC-DC converter of the elemental motion beyond above-mentioned and Fig. 7 is roughly the same.

In Figure 14, identical with Fig. 7, even because load change, also almost constant during the primary side supply capability from the primary side of transformer (5), therefore with the 1st dc output end (10,11) of first secondary winding (5b) side that is connected transformer (5) on load change irrelevant, can take out needed voltage from the 2nd dc output end (18,19) through the 2nd rectifier smoothing circuit (17) on the second subprime winding (5c) that is connected transformer (5).Thereby, even in Figure 14, also can obtain effect and the effect roughly the same with Fig. 7.Particularly, in Figure 14, compare,, therefore have miniaturization and the lightweight advantage that to seek transformer (5) because the quantity of the secondary winding of transformer (5) is few with Fig. 7.

In addition, the multi-output current-resonant type DC-DC converter of the present invention's the 10th example shown in Figure 15 is replaced into four the 1st output rectifier diodes being connected by bridge-type to the 1st rectifier smoothing circuit (9) of the two ripple rectification types that are made of two the 1st whole diodes (7a, 7b) of output and one the 1st output smoothing capacitor (8) shown in Figure 11, and (7a～7d) and the 1st rectifier smoothing circuit (9) of the full-wave rectification bridge type of one the 1st output smoothing capacitor (8) formation make the polarity of grade winding (5g) for the third time of transformer (5) opposite with polarity shown in Figure 11.In example shown in Figure 15, because the polarity of the level winding (5g) for the third time of transformer (5) is opposite with the 1st and second subprime winding (5b, 5c), therefore additional output control is carried out on-off action with MOS-FET (50) synchronously with the conduction period of the 2nd main MOS-FET (2).Other structure is identical with the multi-output current-resonant type DC-DC converter of Figure 11.

In the multi-output current-resonant type DC-DC converter of Figure 15, (7a～7d) carries out full-wave rectification to four the 1st output rectifier diodes that the alternating voltage that takes place at first secondary winding (5b) two ends of transformer (5) is connected by bridge-type, through the 1st output smoothing capacitor (8), from the 1st dc output end (10,11) output smoothing the 1st VD V _O1Detect the voltage V of the 1st output smoothing capacitor (8) in the 1st rectifier smoothing circuit (9) by the 1st output voltage detecting circuit (12) _O1, this detects the error signal V of the reference voltage of voltage and regulation the 1st output voltage values _E1The feedback signal input terminal (FB) that the luminescence unit (13a) of process photoelectrical coupler (13) and photosensitive unit (13b) are delivered to main control circuit (14).Main control circuit (14) is according to the error signal V that is input to the 1st output voltage detecting circuit (12) of feedback signal input terminal (FB) _E1Voltage level, the 1st and the 2nd drive signal V that on each grid of the 1st and the 2nd main MOS-FET (1,2), provides a pulse frequency modulation(FM) (PFM) respectively _G1, V _G2, according to the error signal V of the 1st output voltage detecting circuit (12) _E1The corresponding frequency of voltage level, make the 1st and the 2nd main MOS-FET (1,2) carry out on-off action alternately.Thus, the 1st VD V that exports from the 1st dc output end (10,11) _O1Be controlled as roughly certain value.In addition, additional output control is carried out on-off action with MOS-FET (50) synchronously with the conduction period of the 2nd main MOS-FET (2), exports the 3rd VD V from the 3rd rectifier smoothing circuit (49) through the 3rd dc output end (51,52) _O3Detect the voltage V of the 3rd output smoothing capacitor (48) in the 3rd rectifier smoothing circuit (49) by additional control circuit (53) _O3, detecting the error signal of the reference voltage of voltage and regulation the 3rd output voltage values according to this, additional output control uses MOS-FET (50) synchronous with the switching frequency of the 2nd main MOS-FET (2), modulating pulse width (PWM).Thus, stable from the 3rd VD V of the 3rd rectifier smoothing circuit (49) through the 3rd dc output end (51,52) output _O3The action of elemental motion beyond above-mentioned and the multi-output current-resonant type DC-DC converter of Fig. 7 is roughly the same.

In Figure 15, identical with Figure 11, even because load change, also almost constant during the primary side supply capability from the primary side of transformer (5), therefore as shown in figure 15, even the 1st rectifier smoothing circuit (9) of two ripple rectification types is changed to the full-wave rectification bridge type, the polarity of level winding (5g) for the third time of transformer (5) is become and the 1st and the opposite polarity of second subprime winding (5b, 5c), also can obtain effect and the effect roughly the same with Figure 11.

The multi-output current-resonant type DC-DC converter of the present invention's the 11st example shown in Figure 16 changes to the change of basis from the input voltage E of DC power supply (3) to the control mode of main control circuit (14), control the 1st and the 2nd main MOS-FET (1, the mode of break-make 2), omit the 1st output voltage detecting circuit (12) shown in Figure 7 and photoelectrical coupler (13), at the 1st output rectifier diode (7a shown in Figure 7, be connected the 2nd output control between negative electrode 7b) and the 1st output smoothing capacitor (8) with MOS-FET (54), at the 1st dc output end (10,11) and voltage V according to the 1st output smoothing capacitor (8) is set between the grid of the 2nd output control with MOS-FET (54) _O1Control 2nd output control circuit (55) of the 2nd output control, the voltage V of first secondary winding (5b) of joint detection transformer (5) between each anode of the 1st output rectifier diode (7a, 7b) and the 2nd output control circuit (55) with the break-make of MOS-FET (54) _T21A pair of the 2nd voltage detecting with diode (58a, 58b).The multi-output current-resonant type DC-DC converter of other structure and Fig. 7 is roughly the same.

In the multi-output current-resonant type DC-DC converter of Figure 16, provide according to the 1st and the 2nd drive signal V of (PFM) at each grid of the 1st and the 2nd main MOS-FET (1,2) respectively from the change pulse frequency modulated of the input voltage E of DC power supply (3) from main control circuit (14) _G1, V _G2, according to making the mutual on-off action of the 1st and the 2nd main MOS-FET (1,2) with the corresponding frequency of input voltage E from DC power supply (3).Thus, alternating voltage takes place in the elementary winding (5a) of transformer (5), the corresponding alternating voltage of the turn ratio of induction and elementary winding (5a) and first secondary winding (5b) in first secondary winding (5b).The alternating voltage of induction carries out two ripple rectifications by two the 1st output rectifier diodes (7a, 7b) that constitute the 1st rectifier smoothing circuit (9) in first secondary winding (5b) of transformer (5), by the 1st output smoothing capacitor (8) level and smooth after, the 1st VD V takes place between the 1st dc output end (10,11) _O1In addition, detect the voltage V of the 1st output smoothing capacitor (8) of the 1st rectifier smoothing circuit (9) by the 2nd output control circuit (55) _O1, detecting the error signal of the reference voltage of voltage and regulation the 1st output voltage values according to this, the 2nd output control is synchronous with the switching frequency of MOS-FET (54) and the 1st and the 2nd main MOS-FET (1,2), carries out pulse-width modulation (PWM).Thus, stable from the 1st VD V of the 1st rectifier smoothing circuit (9) through the 1st dc output end (10,11) output _O1The action of elemental motion beyond above-mentioned and the multi-output current-resonant type DC-DC converter of Fig. 7 is roughly the same.

In Figure 16, identical with Fig. 7, even because load change, almost constant during the primary side supply capability from the primary side of transformer (5), by by main control circuit (14) according to change from the input voltage E of DC power supply (3), control the break-make of the 1st and the 2nd main MOS-FET (1,2), can be the voltage control on the elementary winding (5a) that is applied to transformer (5) for certain.Thereby, output control is set with MOS-FET (54,40), by output voltage V based on the 1st and the 2nd rectifier smoothing circuit (9,17) in the 1st and the 2nd rectifier smoothing circuit (9,17) _O1, V _O2The break-make with MOS-FET (54,40) is controlled in each output of control separately, can be from the 1st and the 2nd dc output end (10,11; 18,19), obtain magnitude of voltage the 1st and the 2nd different VD V mutually _O1, V _O2In addition, all identical at the component parts of the dc output circuit that can make primary side, have and reducing the kind of parts, and then when reducing manufacturing cost, improve the advantage of conservative interchangeability.

And in multi-output current-resonant type DC-DC converter shown in Figure 1, if the 1st main MOS-FET (1) conducting of primary side, then the output of primary side control simultaneously is with MOS-FET (40) conducting, in the conduction period of the 1st main MOS-FET (1) according to the output voltage V of the 2nd rectifier smoothing circuit (17) _O2, turn-off the 2nd output control MOS-FET (40).Therefore, when output control switches to when turn-offing from conducting with MOS-FET (40), in controlling conduction period with MOS-FET (40), output flows through sine-shaped electric current I _D2When reducing to 0 sharp, output is controlled with the voltage between drain electrode-source electrode of MOS-FET (40) from 0[V] sharply rise.Thereby, in output control with MOS-FET (40) from conducting to turn-offing when switching, the electric current I that flows through in MOS-FET (40) in output control _D2Do not reduce to fully in 0 the process, because output control is sharply risen with the voltage between the drain electrode-source electrode of MOS-FET (40), therefore use in output control very big switching losses takes place among the MOS-FET (40), have the comprehensive shortcoming that reduces of power converter efficient of multi-output current-resonant type DC-DC converter.Equally, in above-mentioned patent documentation 2 in disclosed multi-output dc/DC converter, because it is synchronous with the conducting of the field-effect transistor of primary side, the switching circuit conducting of primary side, consistent with the output voltage of the output system of not carrying out primary feedback, the ON time of control switch circuit, therefore at switching circuit from conducting to turn-offing when switching, the electric current that flows through in switching circuit does not fully reduce in 0 the process, and the terminal voltage of switching circuit sharply rises.Thereby, very big power loss takes place in switching circuit, there is the comprehensive shortcoming that reduces of power converter efficient of multi-output dc/DC converter.

The multi-output current-resonant type DC-DC converter of expression the present invention the 12nd example makes output control reduce to turn-offing the switching losses that takes place when switching from conducting with MOS-FET (40), as shown in figure 19, output control shown in Figure 1 link position with MOS-FET (40) is altered on the second subprime winding (5c) and the earth connection between the 2nd output smoothing capacitor (16) of transformer (5).The 1st output voltage detecting circuit (12) is made of two resistance (59,60) and the voltage stabilizing didoe (61) that are connected in series between the 1st dc output end (10,11), exports the detection voltage of the 1st output smoothing capacitor (8) and the voltage of voltage regulation V of the voltage stabilizing didoe (61) of regulation the 1st output voltage values from the tie point of two resistance (59,60) _R1The 1st error signal V _E1, be controlled at the electric current that flows through in the luminescence unit (13a) of photoelectrical coupler (13).Thus, owing in the photosensitive unit (13b) of photoelectrical coupler (13), flow through according to the 1st error signal V _E1The electric current of control is therefore from luminescence unit (13a) and the photosensitive unit (13b) of the 1st output voltage detecting circuit (12) through photoelectrical coupler (13), to feedback signal input terminal (FB) transmission the 1st error signal V of main control circuit (14) _E1

Output control circuit (41) comprising: detect the voltage V that takes place in second subprime winding (5c) _T22Rising edge pulse and trailing edge pulse, the 1st and the 2nd detection signal V takes place respectively _TDVoltage-change detecting circuit (42); Detect the voltage V of the 2nd output smoothing capacitor (16) _O2, export it and detect voltage and the reference voltage V of stipulating the 2nd output voltage values _R2The 2nd error signal V _E2The 2nd output voltage detecting circuit (43); The 1st detection signal V has taken place at voltage-change detecting circuit (42) in output _TDAfter, output control is switched to conducting with MOS-FET (40), simultaneously, at voltage-change detecting circuit (42) the 2nd detection signal V has taken place _TDAfter, output is controlled the output signal V that switches to shutoff with MOS-FET (40) _PTThe pwm control circuit as Drive and Control Circuit (44); Output signal V according to pwm control circuit (44) _PT, output is provided to output and controls with the actuating signal V on the grid of MOS-FET (40) _S2Drive circuit (46).

The 2nd output voltage detecting circuit (43) comprising: at the divider resistance (62,63) that is connected in series between the 2nd dc output end (18,19), have the shunt regulator (64) that is connected in parallel on the 2nd output smoothing capacitor (16) and a series circuit of two resistance (65,66); The phase place correction that is connected between the dividing point of the tie point of shunt regulator (64) and a resistance per square (65) and divider resistance (62,63) constitutes with capacitor (67).The dividing point that divides the REF terminal of path processor (64) to be connected to divider resistance (62,63) is connected the luminescence unit (68a) of photoelectrical coupler (68) between the tie point of a side the 2nd dc output end (18) and two resistance (65,66).

As shown in figure 20, connect the auxiliary power circuit that constitutes by rectifier diode (69) and smmothing capacitor (70) at the two ends of second subprime winding (5c), from the negative electrode process smmothing capacitor (70) of rectifier diode (69), supply with driving electric power to the voltage-change detecting circuit (42) that constitutes output control circuit (41), pwm control circuit (44) and drive circuit (46).

Voltage-change detecting circuit (42) comprising: the divider resistance (71,72) that is connected in series at second subprime winding (5c) two ends; The diode (73) that is connected in parallel with the opposing party's divider resistance (72); Base stage (control terminal) is connected the dividing point of divider resistance (71,72), as the detection transistor (74) that detects with switch element.Detect and possess collector electrode (side's main terminal) that is connected pwm control circuit (44) and the emitter (the opposing party's main terminal) that is connected smmothing capacitor (70) with transistor (74).When detecting with transistor (74) conducting and ending, from collector electrode the 1st and the 2nd detection signal V takes place respectively _TDThat is, if voltage V takes place in second subprime winding (5c) _T22The rising edge pulse, then at the voltage of the dividing point generation positive polarity of divider resistance (71,72), thus, diode (73) is by back biased the time, detection from base stage to emitter that flow through electric current from becomes conducting with transistor (74), detects from collector electrode the 1st detection signal V to take place with transistor (74) _TDIf voltage V takes place in second subprime winding (5c) _T22The trailing edge pulse, then at the voltage of the dividing point generation negative polarity of divider resistance (71,72), diode (73) is by forward bias.Thus, the detection of not flowing through electric current between base-emitter becomes with transistor (74) and ends, and detects and from collector electrode the 2nd detection signal V takes place with transistor (74) _TD

Pwm control circuit (44) possesses the discharge usefulness resistance (75) that is connected between the tie point of rectifier diode (69) and smmothing capacitor (7 point) and the collector electrode that detects with transistor (74), comparator (76), the integrating condenser (77) that between the reversed input terminal (-) of the tie point of rectifier diode (69) and smmothing capacitor (70) and comparator (76), is connected, the charging usefulness resistance (78) that between discharge is with resistance (75) and the detection tie point with the tie point of transistor (74) and the reversed input terminal (-) of integrating condenser (77) and comparator (76), is connected, with the discharge diode (79) that charges and be connected in parallel with resistance (78), the series circuit of the electric current brownout resistance (80) that is connected in parallel with smmothing capacitor (70) and the photosensitive unit (68b) of photoelectrical coupler (68).Non-inverting input (+) of comparator (76) is connected to the tie point of the photosensitive unit (68b) of electric current brownout resistance (80) and photoelectrical coupler (68), and lead-out terminal is connected to drive circuit (46).Discharge with resistance (75), integrating condenser (77), charge and use diode (79) to constitute integrating circuit, after detection becomes conducting with transistor (74), owing to the 1st detection signal V takes place from collector electrode with resistance (78) and discharge _TD, therefore flow through charging current with resistance (78) and detection with transistor (74) by smmothing capacitor (70), integrating condenser (77), charging, integrating condenser (77) is charged.According to flowing through integrating condenser (77) and the charging charging current with resistance (78), integrating condenser (77) is represented and the voltage V that takes place in second subprime winding (5c) with the voltage of the tie point of resistance (78) with charging _T22The 1st integral output signal V of integrated value correspondence _CW1(Figure 21 (B)).

When detect become with transistor (74) end after owing to from the collector electrode that detects with transistor (74) the 2nd detection signal V takes place _TD, the electric charge that therefore is stored in the integrating condenser (77) discharges according to the discharging current that flows through with diode (79) with resistance (75) and discharge by discharge.According to the discharging current that flows through with diode (79) with resistance (75) and discharge by discharge, integrating condenser (77) is represented and the voltage V that takes place in second subprime winding (54) with the voltage of the tie point of diode (79) with discharge _T22Corresponding the 2nd integral output signal V of integrated value _CW2(Figure 21 (B)).The photosensitive unit (68b) of electric current brownout resistance (80) and photoelectrical coupler (68) constitutes error voltage generation circuit, from electric current brownout resistance (80) and the tie point generation of the photosensitive unit (68b) of photoelectrical coupler (68) and the 2nd error signal V of the 2nd output voltage detecting circuit (43) _E2The error voltage V of corresponding level _PC(Figure 21 (B)).Comparator (76) is the error voltage V that is input to non-inverting input (+) _PCWith by the 1st and the 2nd integral output signal V that is input to reversed input terminal (-) _CW1, V _CW2The charging/discharging voltage V of the integrating condenser (77) that constitutes _CWCompare, if the charging/discharging voltage V of integrating condenser (77) _CWRatio error voltage V _PCLow, the output signal V of high voltage (H) level then takes place _PTIf, the charging/discharging voltage V of integrating condenser (77) _CWRatio error voltage V _PCThe output signal V of low-voltage (L) level then takes place in height _PT

Drive circuit (46) comprising: export with PNP transistor (82) with NPN transistor (81) and low-voltage with the high voltage output that smmothing capacitor (70) is connected in parallel; The biasing resistor (83) that is connected between two base stages (control terminal) of the tie point of rectifier diode (69) and smmothing capacitor (70) and NPN transistor (81) and PNP transistor (82) (switching device); Be connected in the output resistance (84) of two emitters (side main terminal) of NPN transistor (81) and PNP transistor (82).The collector electrode of NPN transistor (81) (the opposing party's main terminal) is connected in the tie point of rectifier diode (69) and smmothing capacitor (70), and the collector electrode of PNP transistor (82) (the opposing party's main terminal) is connected in the earth terminal (lower end) of smmothing capacitor (70).

During action, as output signal V from comparator (76) output HIGH voltage (H) level _PTAfter, the conducting and ending respectively of NPN transistor (81) and PNP transistor (82) is flow through electric current from the emitter of NPN transistor (81) through output resistance (84), and the actuating signal V of high voltage (H) level is provided at grid _S2Output control switch to conducting with MOS-FET (40).Otherwise, if from the output signal V of comparator (76) output LOW voltage (L) level _PT, then NPN transistor (81) and PNP transistor (82) become respectively by and conducting, flow through electric current from the emitter of output resistance (84) by PNP transistor (82), the actuating signal V of low-voltage (L) level is provided at grid _S2Output control switch to shutoff with MOS-FET (40).Other structure and multi-output current-resonant type DC-DC converter in the past shown in Figure 35 are roughly the same.

After the 1st main MOS-FET (1) switches to conducting, flow through electric current I by current resonance with the leakage inductance (5d) of capacitor (4), transformer (5), the elementary winding (5a) and the 1st main MOS-FET (1) of transformer (5) from DC power supply (3) _Q1Thus, in the elementary winding (5a) of transformer (5), take place in the voltage, shown in Figure 21 (A), the voltage V of induction positive polarity in second subprime winding (5c) _T22The voltage V of induction in second subprime winding (5c) _T22When being input to the 2nd rectifier smoothing circuit (17), be input to the voltage-change detecting circuit (42) in the output control circuit (41), detect voltage V _T22The rising edge pulse.At this moment, at the voltage of the dividing point generation positive polarity of divider resistance (71,72), diode (73) reverse bias, owing to flow through electric current to emitter from the base stage that detects with transistor (74), become conducting, therefore the 1st sensed current signal V takes place from the collector electrode that detects with transistor (74) _TDThus, integrating condenser (77) is used resistance (78) by charging and is detected with transistor (74), with the voltage charging of smmothing capacitor (76), at the integrating condenser (77) and the 1st integral output signal V shown in the tie point generation Figure 21 (B) that uses resistance (78) that charges _CW1At this moment, as with shown in the solid line of Figure 21 (B) like that, the charging voltage V of the integrating condenser (77) that reduces according to exponential function along with the process of time _CWBe applied to the reversed input terminal (-) of comparator (76).In addition, the 2nd output voltage detecting circuit (43) detects the voltage V of the 2nd output smoothing capacitor (16) _O2,, therefore export the reference voltage V of shunt regulator (64) from the tie point of two resistance (65,66) because shunt regulator (64) is defined in detection voltage and the 2nd output voltage values that the dividing point of divider resistance (62,63) takes place _R2With detection voltage V _O2The 2nd error signal V _E2, be controlled at the electric current that flows through in the luminescence unit (68a) of photoelectrical coupler (68).Thus, in the photosensitive unit (68b) of photoelectrical coupler (68), flow through by the 2nd error signal V _E2The electric current of control is shown in the dotted line of Figure 21 (B), according to the voltage V of the 2nd output smoothing capacitor (16) _O2, the error voltage V that level changes _PCBe applied to non-inverting input (+) of comparator (76) from the electric current brownout resistance (80) and the tie point of the photosensitive unit (68b) of photoelectrical coupler (68).

Charging voltage V when the integrating condenser (77) of the reversed input terminal (-) that is applied to comparator (76) _CWReach at the moment t shown in Figure 21 (B) _ONBe applied to the error voltage V on non-inverting input (+) _PCAfter, comparator (76) is anti-phase output-voltage levels, and the output signal V of high voltage (H) level takes place _PTThus, because NPN transistor (81) conducting of drive circuit (46), PNP transistor (82) ends, and therefore through output resistance (84), provides the actuating signal V of high voltage (H) level shown in Figure 21 (C) on the grid of output control with MOS-FET (40) _S2, output control switches to conducting with MOS-FET (40) from shutoff.At this moment, as Figure 21 (D) and (E), output is controlled with the voltage V between drain electrode-source electrode of MOS-FET (40) _Q3Become roughly 0[V], in controlling with MOS-FET (40), output begins to flow through sine-shaped electric current I _Q3

Then,, the 1st main MOS-FET (1) has no progeny when switching to close, shown in Figure 21 (B), and the voltage V of induction negative polarity in second subprime winding (5c) _T22, be input to the 2nd rectifier smoothing circuit (17) and voltage-change detecting circuit (42).Voltage-change detecting circuit (42) is when detecting voltage V _T22The trailing edge pulse time, because voltage in the dividing point generation negative polarity of divider resistance (71,72), diode (73) forward bias, therefore block the electric current that detects with between the base-emitter of transistor (74), end detecting to switch to, the 2nd detection signal V takes place from collector electrode with transistor (74) _TDThus, according to the discharging current that flows through with diode (79) with resistance (75) and discharge by discharge, integrating condenser (77) discharge is at the integrating condenser (77) and the 2nd integral output signal V shown in the tie point generation Figure 21 (B) that uses diode (79) that discharges _CW2The 2nd integral output signal V _CW2Shown in the solid line of Figure 21 (B), be along with the voltage of time according to the exponential function increase, be applied to the reversed input terminal (-) of comparator (76).On the other hand, according to the voltage V of negative polarity of induction in second subprime winding (5c) _T22The 2nd output rectifier diode (15) reverse bias, the sine-shaped electric current I that in output is controlled with MOS-FET (40), flows through _Q3Shown in Figure 21 (E), block and become to be roughly 0.

Then, as the discharge voltage V of the integrating condenser (77) of the reversed input terminal (-) that is applied to comparator (76) _CWIf at the moment t shown in Figure 21 (B) _OFFWith the error voltage V that is applied to non-inverting input (+) _PCAfter equating, comparator (76) is at the output signal V of low-voltage (L) level _PTLast anti-phase output-voltage levels.Thus, because NPN transistor (81) is ended PNP transistor (82) conducting, so the actuating signal V of low-voltage (L) level shown in Figure 21 (C) _S2The output control that is provided on the grid through output resistance (84) switches to shutoff with MOS-FET (40) from conducting.At this moment, shown in Figure 21 (D), output is controlled with the voltage V between drain electrode-source electrode of MOS-FET (40) _Q3From 0[V] rise to high voltage (H) level.Like this, the voltage V that in the second subprime winding (5c) that has detected transformer (5), takes place of the voltage-change detecting circuit (42) in the output control circuit (41) _T22The trailing edge pulse after, if through certain hour, the 2nd output rectifier diode (15) reverse bias, the then sine-shaped electric current I that in output is controlled with MOS-FET (40), flows through _Q3Block and become to be roughly 0, then, because according to the actuating signal V of low-voltage (L) level _S2, output control switches to shutoff with MOS-FET (40), therefore can reach Zero Current Switch completely.

As mentioned above, pwm control circuit (44) is at moment t _ONOutput control is switched to conducting with MOS-FET (40) from shutoff, at moment t _OFFOutput control is switched to shutoff with MOS-FET (40) from conducting.Moment t _ONBe after the 1st main MOS-FET (1) conducting, the charging voltage V of integrating condenser (77) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCTime.In addition, moment t _OFFBe after the 1st main MOS-FET (1) conducting, the discharge of integrating condenser (77) electricity V _CWError voltage V with the photosensitive unit (68b) of photoelectrical coupler (68) _PCBecome the equal time.Voltage V when the 2nd output smoothing capacitor (16) _O2Reference voltage V than shunt adjuster (64) _R2When high, the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCLevel low.Thereby, the charging voltage V of integrating condenser (77) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCMoment t _ONPostpone the discharge voltage V of integrating condenser (77) _CWError voltage V with the photosensitive unit (68b) of photoelectrical coupler (68) _PCBecome equal moment t _OFFIn advance.Thus, control with the actuating signal V on the grid of MOSFET (40) owing to be provided to output from output control circuit (41) _S2Pulsewidth narrow down, output control shortened with the conduction period of MOS-FET (40), therefore in the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17), flow through electric current during shortening, the voltage V of the 2nd output smoothing capacitor (16) _O2Reduce.

Otherwise, as the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) _O2Reference voltage V than the shunt regulator (64) in the 2nd output voltage detecting circuit (43) _R2When low, the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCLevel uprise.Thereby, the charging voltage V of integrating condenser (77) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCMoment V _O2In advance, the discharge voltage V of integrating condenser (77) _CWError voltage V with the photosensitive unit (68b) of photoelectrical coupler (68) _PCBecome equal moment t _OFFPostpone.Thus, control with the actuating signal V on the grid of MOS-FET (40) owing to be provided to output from output control circuit (41) _S2The pulse duration broadening, output control is elongated with the conduction period of MOS-FET (40), therefore in the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17), flow through electric current during prolong the voltage V of the 2nd output smoothing capacitor (16) _O2Rise.Like this, because the output control voltage V of the conduction period of MOS-FET (40) according to the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) _O2Control, therefore can take out the 2nd roughly certain VD V from the 2nd dc output end (18,19) _O2The action of elemental motion beyond the multi-output current-resonant type DC-DC converter in the 12nd example shown in Figure 19 above-mentioned and multi-output current-resonant type DC-DC converter shown in Figure 1 is roughly the same.

In the 12nd example shown in Figure 19, when the 1st main MOS-FET (1) conducting, detect the exciting voltage V that in second subprime winding (5c), takes place by voltage-change detecting circuit (42) _T22The rising edge pulse, the 1st detection signal V takes place in voltage-change detecting circuit (42) _TDThen, by the charging voltage V of pwm control circuit (44) in integrating condenser (77) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCMoment t _ON, output control is switched to conducting with MOS-FET (40), thus, in the second subprime winding (5c) of transformer (5), flow through resonance current as load current.

In addition, when the 1st main MOS-FET (1) turn-offs, owing to block exciting current by the 1st main MOS-FET (1), so voltage-change detecting circuit (42) detects the voltage V that takes place in the second subprime winding (5c) of transformer (5) _T22The trailing edge pulse, the 2nd detection signal V takes place _TDVoltage V according to the negative polarity of induction in second subprime winding (5c) _T22, the sine-shaped electric current I that in output is controlled with MOS-FET (40), flows through _Q3Block and become to be roughly 0, the electric current I that in second subprime winding (54), flows through _Q3Reduce to fully after 0, at the discharge voltage V of integrating condenser (77) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCMoment t _OFF, because output control MOS-FET (40) switches to shutoff, therefore output control becomes Zero Current Switch (ZCS) with MOS-FET (40).Like this, owing to be not to carry out primary side output independently to control the switch motion of using MOS-FET (40), but feasible in fact synchronous with the switch motion of the 1st main MOS-FET (1), therefore can reduce output and control the switching losses of using among the MOS-FET (40).Particularly, when the 1st main MOS-FET (1) being switched to shutoff, though switching current increases, yet the loss of cutting off resonance current is roughly the same level with current comparing, because the increase of the switching losses among the 1st main MOS-FET (1) is few, therefore can synthetically increase substantially the power converter efficient of multi-output current-resonant type DC-DC converter.

If the 1st main MOS-FET (1) becomes conducting, then flows through exciting current from the elementary winding (5a) and the 1st or the 2nd main MOS-FET (1,2) of DC power supply (3) by transformer (5), in first secondary winding (5b) of transformer (5) and second subprime winding (5c) exciting voltage takes place.This exciting voltage is owing to take place simultaneously in each winding (5a, 5b, 5c) of transformer (5) simultaneously, therefore also can be determined at the exciting voltage that takes place in which winding, and for example, when the voltage-change detecting circuit (42) that is connected on the second subprime winding (5c) detects the voltage V that takes place in second subprime winding (5c) _T22The rising edge pulse, the 1st detection signal V takes place _TDAfter, pwm control circuit (44) switches to conducting to output control with MOS-FET (40), thus, flows through the resonance current as load current in second subprime winding (5c).In addition,, the 1st main MOS-FET (1) has no progeny when switching to close, owing to block the exciting current that flows through by the 1st main MOS-FET (1), so voltage-change detecting circuit (42) detects the voltage V that takes place in the second subprime winding (5c) of transformer (5) _T22The trailing edge pulse, the 2nd detection signal V takes place _TD, then, pwm control circuit (44) switches to shutoff to output control with MOS-FET (40).

Thus, because the electric current I that in second subprime winding (5c), flows through _Q3After fully reducing, output control is switched to shutoff with MOS-FET (40), therefore output control becomes Zero Current Switch (ZCS) with MOS-FET (40).Like this, owing to be not to export the switch motion of control with MOS-FET (40) independently, but make it in fact synchronous with the switch motion of the 1st or the 2nd main MOS-FET (1,2), therefore can reduce the switching losses of output control with MOS-FET (40).In this case, though the 1st or 2MOS-FET (1,2) switch to that switching current increases when turn-offing, but because the 1st or the 2nd main MOS-FET (1,2) carries out break-make to resonance current, therefore consequent loss is compared with the past more almost is identical level, and the increase of the switching losses among the 1st or the 2nd main MOS-FET (1,2) is few.Thereby, can synthetically increase substantially the power converter efficient of multi-output current-resonant type DC-DC converter.

According to the present invention, since in fact synchronous with the switch motion of primary side switch element, carry out the switch motion of primary side output control with switch element, therefore can reduce the switching losses of output control with switch element.In addition, owing to few from the increase that conducting switches to the switching losses that takes place when turn-offing, therefore can synthetically increase substantially the power converter efficient of multi-output current-resonant type DC-DC converter the primary side switch element.

Multi-output current-resonant type DC-DC converter shown in Figure 19 can change.For example, the multi-output current-resonant type DC-DC converter of expression the present invention the 13rd example is altered to primary side output control shown in Figure 19 link position with MOS-FET (40) between the 2nd output rectifier diode (15) and the 2nd output smoothing capacitor (16) that constitutes the 2nd rectifier smoothing circuit (17) as shown in figure 22.Other structure and multi-output current-resonant type DC-DC converter shown in Figure 19 are roughly the same.In addition, the action of the action of multi-output current-resonant type DC-DC converter shown in Figure 22 and multi-output current-resonant type DC-DC converter shown in Figure 19 is roughly the same.

Among Figure 22, identical with Figure 19, when the 1st main MOS-FET (1) conducting, detect the exciting voltage V that in the second subprime winding (5c) of transformer (5), takes place by voltage-change detecting circuit (42) _T22The rising edge pulse after because at the charging voltage V of integrating condenser (77) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCMoment t _ON, output control is switched to conducting with MOS-FET (40), therefore in the second subprime winding (5c) of transformer (5), flow through resonance current as load current.In addition, when the 1st main MOS-FET (1) switches to shutoff, detect the voltage V that in second subprime winding (5c), takes place by voltage-change detecting circuit (42) _T22The trailing edge pulse, in second subprime winding (5c), induced the voltage V of negative polarity _T22After, owing to discharge voltage V at integrating condenser (77) _CWError voltage V with the photosensitive unit (68b) of photoelectrical coupler (68) _PCThe moment t that equates _OFF, output control switches to shutoff with MOS-FET (40), therefore the electric current I that flows through in second subprime winding (5c) _Q3Reduce to fully after 0, output control is switched to shutoff with MOS-FET (40), therefore output control becomes Zero Current Switch with MOS-FET (40).Thereby the 13rd example is also identical with the 12nd example, can reduce by the switching losses of output control with MOS-FET (40) generation, synthetically increases substantially the power converter efficient of multi-output current-resonant type DC-DC converter.

The multi-output current-resonant type DC-DC converter of expression the present invention the 14th example makes the polarity of second subprime winding (5c) shown in Figure 19 opposite as shown in figure 23.Thereby, in the 14th example, when the 2nd main MOS-FET (2) conducting, detect the exciting voltage V that in second subprime winding (5c), takes place by voltage-change detecting circuit (42) _T22The rising edge pulse, the 1st detection signal V has taken place _TDAfter, the charging voltage V of the integrating condenser (77) in pwm control circuit (44) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCMoment t _ON, output control is switched to conducting with MOS-FET (40).In addition, when the 2nd main MOS-FET (2) switches to shutoff, detect the voltage V that in second subprime winding (5C), takes place by voltage-change detecting circuit (42) _T22The trailing edge pulse, the 2nd detection signal V has taken place _TDAfter, at the discharge voltage V of integrating condenser (77) _CWBecome error voltage V with the photosensitive unit (68b) of photoelectrical coupler (68) _PCThe moment t that equates _OFF, output control is switched to shutoff with MOS-FET (40).Other structure is identical with the multi-output current-resonant type DC-DC converter of embodiment 1 shown in Figure 1.In addition, the action of action beyond multi-output current-resonant type DC-DC converter shown in Figure 23 above-mentioned and multi-output current-resonant type DC-DC converter shown in Figure 19 is roughly the same.

In the 14th example, when the 2nd main MOS-FET (2) conducting, detect the exciting voltage V that in the second subprime winding (5c) of transformer (5), takes place by voltage-change detecting circuit (42) _T22The rising edge pulse after because the charging voltage V of integrating condenser (77) in pwm control circuit (44) _CWReach the error voltage V of the photosensitive unit (68b) of photoelectrical coupler (68) _PCMoment t _ON, output control is switched to conducting with MOS-FET (40), therefore in the second subprime winding (5c) of transformer (5), flow through resonance current as load current.In addition, when the 2nd main MOS-FET (2) turn-offs, detect the voltage V that in second subprime winding (5c), takes place by voltage-change detecting circuit (42) _T22The trailing edge pulse after, at the discharge voltage V of pwm control circuit (44) integrates capacitor (77) _CWBecome error voltage V with the photosensitive unit (68b) of photoelectrical coupler (68) _PCThe moment t that equates _OFF, output control is switched to shutoff with MOS-FET (40).Thereby, the electric current I that in the second subprime winding (5c) of transformer (5), flows through _Q3Reduce to fully after 0, output control is switched to shutoff with MOS-FET (40), can make output control reach Zero Current Switch with MOS-FET (40).Like this, control with the switching losses among the MOS-FET (40) owing to can reduce output, therefore the 14th example is also identical with the 12nd example, can synthetically increase substantially the power converter efficient of multi-output current-resonant type DC-DC converter.

And then, in the 14th example, in the conduction period of the 1st main MOS-FET (1), owing to take out the 1st stable VD V through the 1st rectifier smoothing circuit (9) from first secondary winding (5b) _O1, in the conduction period of the 2nd main MOS-FET (2), take out the 2nd VD V that has controlled output valve by output control with the on-off action of MOS-FET (40) through the 2nd rectifier smoothing circuit (17) from second subprime winding (5c) _O2, therefore with in the conduction period of the 1st main MOS-FET (1), take out the 1st and the 2nd VD V simultaneously _O1, V _O2The the 12nd and the 13rd example compare, have the advantage that multi-output current-resonant type DC-DC converter is more effectively moved.

The multi-output current-resonant type DC-DC converter of expression the present invention the 15th example as shown in figure 24, the control mode of main control circuit shown in Figure 19 (14) is changed to the change of basis from the input voltage E of DC power supply (3), control the 1st and the 2nd main MOS-FET (1, the mode of break-make 2), omit the 1st output voltage detecting circuit (12) shown in Figure 19 and photoelectrical coupler (13), between the negative electrode of the 1st output rectifier diode (7) shown in Figure 19 and the 1st output smoothing capacitor (8), is connected the 2nd output and controls usefulness MOS-FET (54), at the 1st dc output end (10,11) and between the grid of the 2nd output control with MOS-FET (54), be provided with voltage V according to the 1st output smoothing capacitor (8) _O1Control 2nd output control circuit (55) of the 2nd output control with the break-make of MOS-FET (54).

Main control circuit shown in Figure 24 (14) is fixed the conduction period of the 1st main MOS-FET (1), according to change from the input voltage E of DC power supply (3), the conduction period of the 2nd main MOS-FET (2) is changed, can control the conducting duty ratio of the 1st main MOS-FET (1).The 2nd output control circuit (55) comprising: detect the voltage V that takes place in first secondary winding (5b) of transformer (5) _T21Rising edge pulse and trailing edge pulse, the 1st and the 2nd detection signal V takes place respectively _TD1The 2nd voltage-change detecting circuit (85); Detect the voltage V of the 1st output smoothing capacitor (8) of the 1st rectifier smoothing circuit (9) _O1, export it and detect voltage and the reference voltage V of stipulating the 1st output voltage values _R1The 1st point tolerance signal V _E1The 3rd output voltage detecting circuit (86); Occur in the 2nd voltage-change detecting circuit (85) the 1st detection signal V has taken place _TD1After, the 2nd inspection signal V when switching to conducting, has been taken place at the 2nd voltage-change detecting circuit (85) with MOS-FET (54) in the 2nd output control _TD1After, the output signal V that switches to shutoff with MOS-FET (54) is controlled in the 2nd output _PT12PWM control circuit (87); Output signal V according to 2PWM control circuit (87) _PT1, output is provided to 2nd drive circuit (88) of the 2nd output control with the 2nd actuating signal VS1 on the grid of MOS-FET (54); Through luminescence unit (89a) and photosensitive unit (89b), the 1st error signal V of the 3rd output voltage detecting circuit (86) _E1Be delivered to the photoelectrical coupler (89) of 2PWM control circuit (87).The detailed structure of each circuit (85～89) that constitutes the 2nd output control circuit (55) is identical with the detailed structure of each circuit (42～44,46,68) that constitutes output control circuit (41) shown in Figure 20.Other structure and multi-output current-resonant type DC-DC converter shown in Figure 19 are roughly the same.

The action of multi-output current-resonant type DC-DC converter shown in Figure 24 is removed by the voltage V based on the 1st output smoothing capacitor (8) _O1, by the break-make of the 2nd output control circuit (55) control the 2nd output control, the 1st VD V between the 1st dc output end (10,11) with MOS-FET (54) _O1Be controlled to be beyond certain this point, roughly the same with the action of multi-output current-resonant type DC-DC converter shown in Figure 19.

In Figure 24, during the 1st main MOS-FET (1) conducting, detect the exciting voltage V that in the 1st and the second subprime winding (5b, 5c) of transformer (5), takes place by each voltage-change detecting circuit (85,42) _T21, V _T22The rising edge pulse, the 1st detection signal V has taken place _TD1, V _TD2After, the charging voltage V of the integrating condenser (77) in each pwm control circuit (87,44) _CWArrive the error voltage V of the photosensitive unit (89b, 68b) of photoelectrical coupler (89,68) _PCMoment t _ON, each output control is switched to conducting with MOS-FET (40,54).Thus, in the 1st and the second subprime winding (5b, 5c) of transformer (5), flow through resonance current as load current.In addition, when the 1st main MOS-FET (1) turn-offs, detect the voltage V that in the 1st and the second subprime (5b, 5c) of transformer (5), takes place by each voltage-change detecting circuit (85,42) _T21, V _T22The trailing edge pulse, detection signal V has taken place the 2nd time _TD1, V _TD2After, the discharge voltage V of the integrating condenser (77) in each pwm control circuit (87,44) _CWBecome error voltage V with the photosensitive unit (89b, 68b) of photoelectrical coupler (89,68) _PCThe moment t that equates _OFF, each output control is switched to shutoff with MOS-FET (40,54).Thereby, the electric current I that in the 1st and the second subprime winding (5B, 5C) of transformer (5), flows through _Q31, I _Q32Reduce to fully after 0,, therefore can reach the Zero Current Switch of each output control with MOS-FET (40,54) because each output control switches to shutoff with MOS-FET (40,54).Thereby, can reduce each output and control with the switching losses among the MOS-FET (40,54), synthetically increase substantially the power converter efficient of multi-output current-resonant type DC-DC converter.

In addition, in Figure 24, even be connected the 1st and the 2nd dc output end (10,11; 18, load change 19), also almost constant during the primary side supply capability from the primary side of transformer (5), by main control circuit and of the change of (14) basis from the input voltage E of DC power supply (3), the the 1st and the 2nd main MOS-FET (1,2) is carried out break-make control, can be the voltage control on the elementary winding (5a) that is applied to transformer (5) for certain.Thereby, output control is set with MOS-FET (40,54) respectively in the 1st and the 2nd rectifier smoothing circuit (9,17), by based on each output voltage V _O1, V _O2, the break-make with MOS-FET (40,54) is controlled in each output of control separately, can be from the 1st and the 2nd dc output end (10,11; 18,19) obtain magnitude of voltage the 1st and the 2nd different VD V mutually _O1, V _O2In addition, the dc output circuit of primary side is all constituted with parts of the same race, have and to reduce different types of parts, reduce cost, simultaneously, can improve the advantage of conservative interchangeability.

In the 12nd～the 15th example, use each rectifier smoothing circuit (9,17) that has constituted primary side by the halfwave rectifier type of output rectifier diode (7,15) and an output smoothing capacitor (8, a 16) formation, and also can be with formations such as two ripple rectification types or full-wave rectification bridge types.For example, the multi-output current-resonant type DC-DC converter of expression the present invention the 16th example as shown in figure 25, between first secondary winding (5b) and the 1st output smoothing capacitor (8) of transformer shown in Figure 19 (5), four the 1st output of bridge-type connection rectifier diode (7a～7d), the 1st rectifier smoothing circuit (9) of embodiment 1 is changed to the structure of full-wave rectification bridge type, in the second subprime winding (5c) of transformer shown in Figure 19 (5), centre tap (5i) is set, connect a pair of the 2nd output rectifier diode (15a at the two ends of second subprime winding (5c), 15b), at each the 2nd output rectifier diode (15a, be connected the 2nd output smoothing capacitor (16) between the centre tap (5i) of the tie point of negative electrode 15b) and second subprime winding (5c), the 2nd rectifier smoothing circuit (17) of Figure 19 is changed to the structure of two ripple rectification types, between a side's who constitutes the 2nd rectifier smoothing circuit (17) output rectifier diode (15a) and the 2nd output smoothing capacitor (16), connected output control MOS-FET (40), between the opposing party's the 2nd output rectifier diode (15b) and the 2nd output smoothing capacitor (16), connected the 2nd output control MOS-FET (54).

Main control circuit (14) makes the mutual conducting of the 1st and the 2nd main MOS-FET (1,2) with 50% duty ratio.In addition, in Figure 25, in output control circuit shown in Figure 19 (41), add: the voltage V that detects generation between the lower end of the second subprime winding (5c) of transformer (5) and centre tap (5i) _T22bRising edge pulse or trailing edge pulse, the 1st or the 2nd detection signal V takes place respectively _TDbThe 2nd voltage-change detecting circuit (85); The the 1st or the 2nd detection signal V has taken place at the 2nd voltage-change detecting circuit (85) _TDbAfter, take place respectively the output signal V that switches to conducting or shutoff with MOS-FET (54) to be controlled in the 2nd output _PTb2PWM control circuit (87); Output signal V according to 2PWM control circuit (87) _PTb, output is provided to the 2nd output and controls with the 2nd actuating signal V on the grid of MOS-FET (54) _S2bThe 2nd drive circuit (88), through luminescence unit (89a) and photosensitive unit (89b) the error signal V of the 2nd output voltage detecting circuit (43) _E2Be delivered to the photoelectrical coupler (89) of 2PWM control circuit (87).The corresponding circuits (42,44,46) of the detailed structure of the 2nd voltage-change detecting circuit (85), 2PWM control circuit (87) and the 2nd drive circuit (88) and output circuit shown in Figure 20 (41) is roughly the same, and circuit structure in addition and multi-output current-resonant type DC-DC converter shown in Figure 19 are roughly the same.

In the multi-output current-resonant type DC-DC converter of the 16th example, (7a～7d) carries out full-wave rectification to four the 1st output rectifier diodes that the alternating voltage that takes place at first secondary winding (5b) two ends of transformer (5) is connected by bridge-type, through the 1st output smoothing capacitor (8), from the 1st dc output end (10,11) output smoothing the 1st output VD V _O1

During the 1st main MOS-FET (1) conducting, upper end with the elementary winding (5a) of transformer (5) take place be positive voltage the time, the voltage V of generation positive polarity between the upper end of the second subprime winding (5c) of transformer (5) and centre tap (5i) _T22aDetect the voltage V of positive polarity by voltage-change detecting circuit (42) _T22aThe rising edge pulse, the 1st detection signal V takes place _TDaThus, the charging of the integrating condenser (77) in the pwm control circuit (44), the charging voltage V of integrating condenser (77) _CWReduce and be applied to the reversed input terminal (-) of comparator (76) according to exponential function along with the time.On the other hand, detect the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) by the 2nd output voltage detecting circuit (43) in the output control circuit (41) _O2, detect voltage and the 2nd reference voltage V of stipulating the 2nd output voltage values according to this _R2The 2nd error signal V _E2, be controlled at the electric current that flows through in the luminescence unit (68a) of photoelectrical coupler (68) and the photosensitive unit (68b).At this moment, with the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectification smmothing capacitor (17) _O2The error voltage V that corresponding level changes _PCElectric current brownout resistance (80) in the pwm control circuit (44) and the tie point of the photosensitive unit (68b) of photoelectrical coupler (68) are applied to non-inverting input (+) of comparator (76).

Be applied to the charging voltage V of integrating condenser (77) of the reversed input terminal (-) of the comparator (76) in the pwm control circuit (44) _CWIf reach the error voltage V that is applied to non-inverting input (+) _PC, then the voltage level of the lead-out terminal of comparator (76) is anti-phase, and the output signal V of high voltage (H) level takes place _PTaThe actuating signal V of high voltage (H) level is provided with the grid of MOS-FET (40) in output control from drive circuit (46) thus, _S2a, output control switches to conducting with MOS-FET (40) from shutoff.At this moment, output is controlled with the voltage V between drain electrode-source electrode of MOS-FET (40) _Q3aRoughly become 0[V], in controlling with MOS-FET (40), output begins to flow through sine-shaped electric current I _Q3

Then,, the 1st main MOS-FET (1) has no progeny the voltage V of generation between the upper end of the second subprime winding (5c) of transformer (5) and centre tap (5i) when switching to close from conducting _T22aBecome negative polarity.The voltage V of this negative polarity _T22aBe input to the voltage-change detecting circuit (42) in the output control circuit (41), detect voltage V _T22aThe trailing edge pulse, the 2nd detection signal V takes place _TDaThus, integrating condenser (77) discharge in the pwm control circuit (44), the discharge voltage V of integrating condenser (77) _CWAlong with the time is the increase of exponential function ground, be applied to the reversed input terminal (-) of comparator (76).On the other hand, because according to voltage V in the negative polarity of generation between the upper end of the second subprime winding (5c) of transformer (5) and the centre tap (5i) _T22a, a side (15a) of the 2nd output rectifier diode in the 2nd rectifier smoothing circuit (17) is reverse biased, and therefore blocks the sine-shaped electric current I that flows through in output is controlled with MOS-FET (40) _Q3

Then, the discharge voltage V of the integrating condenser (77) on the reversed input terminal (-) of the comparator (76) in being applied to pwm control circuit (44) _CWBecome and the error voltage V that is applied to non-inverting input (+) _PCAfter equating, the voltage level of the lead-out terminal of comparator (76) is anti-phase, and the output signal V of low-voltage (L) level takes place _PTaThe actuating signal V of low-voltage (L) level is provided with the grid of MOS-FET (40) in output control from drive circuit (46) thus, _S2a, output control switches to shutoff with MOS-FET (40) from conducting.At this moment, output is controlled with the voltage V between drain electrode-source electrode of MOS-FET (40) _Q3aFrom 0[V] rise to high voltage (H) level.Like this, the voltage-change detecting circuit (42) in output control circuit (41) detects the voltage V that takes place between the upper end of the second subprime winding (5c) of transformer (5) and centre tap (52) _T22aTrailing edge pulse when having passed through certain hour later on, the electric current I that flows through in MOS-FET (40) in output control _Q3Become zero fully, can reach Zero Current Switch completely.

During the 2nd main MOS-FET (2) conducting, lower end with the elementary winding (5a) of transformer (5) take place be positive voltage the time, the voltage V of generation positive polarity between the lower end of the second subprime winding (5c) of transformer (5) and centre tap (5i) _T22bIn the 2nd voltage-change detecting circuit (85), detect the voltage V of positive polarity _T22bThe rising edge pulse, the 1st detection signal V takes place _TDbThus, the charging of the integrating condenser (77) in the 2PWM control circuit (87), the charging voltage V of integrating condenser (77) _CWReduce and be applied to the reversed input terminal (-) of comparator (76) according to exponential function along with the time.On the other hand, detect the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) by the 2nd output voltage detecting circuit (43) in the output control circuit (41) _O2, detect voltage and the 2nd reference voltage V of stipulating the 2nd output voltage values according to this _R2Voltage regulation 2 error signal V _E2, be controlled at the electric current that flows through in the luminescence unit (89a) of photoelectrical coupler (89) and the photosensitive unit (89b), with the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectification smmothing capacitor (17) _O2The error voltage V that corresponding level changes _PCElectric current brownout resistance (80) in the 2PWM control circuit (87) and the tie point of the photosensitive unit (89b) of photoelectrical coupler (89) are applied to non-inverting input (+) of comparator (76).

Be applied to the charging voltage V of integrating condenser (77) of the reversed input terminal (-) of the comparator (76) in the 2PWM control circuit (87) _CWWhen reaching the error voltage V that is applied to non-inverting input (+) _PCAfter, the voltage level of the lead-out terminal of comparator (76) is anti-phase, and the output signal V of high voltage (H) level takes place _PTbThus, defeated by controlling the actuating signal V that high voltage (H) level is provided with the grid of MOS-FET (54) from the 2nd drive circuit (88) the 2nd _S2b, the 2nd output control switches to conducting with MOS-FET (54) from shutoff.At this moment, the 2nd output is controlled with the voltage V between drain electrode-source electrode of MOS-FET (54) _Q3bRoughly become 0[V], in controlling with MOS-FET (54), the 2nd output begins to flow through sine-shaped electric current I simultaneously _Q3

, the 2nd main MOS-FET (2) has no progeny the voltage V of generation between the lower end of the second subprime winding (5c) of transformer (5) and centre tap (5i) when switching to close from conducting _T22bBecome negative polarity.In the 2nd voltage-change detecting circuit (85), detect voltage V _T22bThe trailing edge pulse, the 2nd detection signal V takes place _TDbThus, the discharge of the integrating condenser (77) in the 2PWM control circuit (87), the discharge voltage V of integrating condenser (77) _CWAlong with the time is the increase of exponential function ground, be applied to the reversed input terminal (-) of comparator (76).On the other hand, because according to voltage V in the negative polarity of generation between the lower end of the second subprime winding (5c) of transformer (5) and the centre tap (5i) _T22b, a side (15b) of the opposing party's the 2nd output rectifier diode is reverse biased, and therefore blocks in the 2nd output is controlled with MOS-FET (54) and flows through sine-shaped electric current I _Q3

Then, the discharge voltage V of the integrating condenser (77) on the reversed input terminal (-) of the comparator (76) in being applied to 2PWM control circuit (87) _CWWith the error voltage V that is applied to non-inverting input (+) _PCAfter equating, then the voltage level of the lead-out terminal of comparator (76) is anti-phase, and the output signal V of low-voltage (L) level takes place _PTbThe actuating signal V of low-voltage (L) level is provided with the grid of MOS-FET (54) in the 2nd output control from the 2nd drive circuit (88) thus, _S2b, the 2nd output control switches to shutoff with MOS-FET (54) from conducting.At this moment, the 2nd output is controlled with the voltage V between drain electrode-source electrode of MOS-FET (54) _Q3bFrom 0[V] rise to high voltage (H) level.Like this, detect the voltage V that between the lower end of the second subprime winding (5c) of transformer (5) and centre tap (5i), takes place at the 2nd voltage-change detecting circuit (85) _T22bTrailing edge pulse when having passed through certain hour later on, the electric current I that flows through in MOS-FET (54) in the 2nd output control _Q3Become zero fully, can reach Zero Current Switch completely.

As mentioned above, each pwm control circuit (44,87) after the 1st or the 2nd main MOS-FET (1,2) conducting, the charging voltage V in integrating condenser (77) _CWReach the error voltage V of the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCMoment t _ON, each output control is switched to conducting with MOS-FET (40,54) from shutoff, after the 1st or the 2nd main MOS-FET (1,2) turn-offs, at the discharge voltage V of integrating condenser (77) _CWError voltage V with the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCBecome equal moment t _OFF, each output control is switched to shutoff with MOS-FET (40,54) from conducting.That is, as the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) _O2Reference voltage V than the shunt regulator (64) in the 2nd output voltage detecting circuit (43) _R2When high, the error voltage V of the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCLevel reduce.Thereby, the charging voltage V of the integrating condenser (77) in each pwm control circuit (44,87) _CWReach the error voltage V of the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCMoment t _ONPostpone, be provided to each output from output control circuit (41) and control with the actuating signal V on the grid of MOS-FET (40,54) _S2a, V _S2bPulse duration narrow down.Thereby, because each output control shortens with conduction period of MOS-FET (40,54), therefore shorten in the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17), flow through electric current during, the voltage V of the 2nd output smoothing capacitor (16) _O2Reduce.

Otherwise, as the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) _O2Reference voltage V than the shunt regulator (64) in the 2nd output voltage detecting circuit (43) _R2When low, the error voltage V of the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCLevel raise.Thereby, the charging voltage V of the integrating condenser (77) in each pwm control circuit (44,87) _CWReach the error voltage V of the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCMoment t _ONIn advance, being provided to each output from output control circuit (41) controls with the actuating signal V on the grid of MOS-FET (40,54) _S2a, V _S2bPulse duration broaden.Thereby, because each output control is elongated with the conduction period of MOS-FET (40,54), therefore in the 2nd output smoothing capacitor (16) of the 2nd rectification output rectifier smoothing circuit (17), flow through electric current during prolong the voltage V of the 2nd output smoothing capacitor (16) _Q2Rise.Like this, because according to the voltage V of the 2nd output smoothing capacitor (16) of the 2nd rectifier smoothing circuit (17) _O2Therefore each output control of control can take out the 2nd roughly certain VD V from the 2nd dc output end (18,19) with the conduction period of MOS-FET (40,54) _O2The action of the elemental motion of multi-output current-resonant type DC-DC converter shown in Figure 25 and multi-output current-resonant type DC-DC converter shown in Figure 19 is roughly the same.

In Figure 25, during the 1st or the 2nd main MOS-FET (1,2) conducting, detect the exciting voltage V that in second subprime winding (5c), takes place by each voltage-change detecting circuit (42,48) _T22a, V _T22bThe rising edge pulse, the 1st detection signal V has taken place _TDa, V _TDbAfter, the charging voltage V of the integrating condenser (77) in each pwm control circuit (44,87) _CWReach the error voltage V of the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCMoment t _ON, each output control is switched to conducting with MOS-FET (40,54).Thus, in second subprime winding (5C), flow through resonance current as load current.

In addition, when the 1st or the 2nd main MOS-FET (1,2) switches to when turn-offing from conducting, detect the voltage V of generation in second subprime winding (5c) by each voltage-change detecting circuit (42,85) _T22a, V _T22bThe trailing edge pulse, detection signal V has taken place the 2nd time _TDa, V _TDbAfter, the discharge voltage V of the integrating condenser (77) in each pwm control circuit (44,87) _CWReach error voltage V with the photosensitive unit (68b, 89b) of photoelectrical coupler (68,89) _PCThe moment t that equates _OFF, each output control is switched to shutoff with MOS-FET (40,54).Thereby, the electric current I that in second subprime winding (5c), flows through _Q3Reduce to fully after 0, because each output control is switched to shutoff with MOS-FET (40,54), therefore each output control becomes Zero Current Switch with MOS-FET (40,54).Like this, can reduce each output control with the switching losses among MOS-FET (40,54), also identical in Figure 25 with Figure 19, can synthetically increase substantially the power converter efficient of multi-output current-resonant type DC-DC converter.And then, in Figure 25, even because load change, also almost constant during the primary side supply capability from the primary side of transformer (5), therefore for example shown in the image pattern 25, constitute the 1st rectifier smoothing circuit (9) with the full-wave rectification bridge type, constitute under the situation of the 2nd rectifier smoothing circuit (17) with two ripple rectification types, have and can obtain effect and effect and the ripple component few 1st and 2nd VD V roughly the same with Figure 19 _O1, V _O2Advantage.

In each above-mentioned example, owing to carry out break-make control with MOS-FET (40) according to the output control that is arranged on primary side, therefore during with MOS-FET (40) conducting, be created in current concentration in the specific output in output control, in other output, do not flow through electric current during.Particularly, in the high shape DC-DC converter that boosts of output voltage, induction high voltage in the secondary winding (5b, 5c) of transformer (5), sharply charging of smmothing capacitor (16), so short and charging current is big between charge period.According to big charging current, have when the conducting of switch element (40) is used in output control current concentration takes place, the power converter loss increases the shortcoming of power converter degradation in efficiency.In order to address this problem, consider in each output, to insert impedance component, avoid the method for current concentration in specific output, but according to the impedance component generation power converter loss of inserting, power converter degradation in efficiency.Figure 26 is that expression is inserted as impedor choke (100) by connecting with second subprime winding (5c), the peak current of crossing in load flow when being suppressed at output control with MOS-FET (40) conducting is avoided the circuit diagram to concentrated the present invention's the 17th example of load current.

In the 17th example shown in Figure 26, possess: be connected in series in regeneration between the tie point of the choke (100) between second subprime winding (5c) and the lead-out terminal (19), the tie point that is connected second subprime winding (5c) and choke (100) and the 2nd output smoothing capacitor (16) and lead-out terminal (18) with diode (101).The actuating signal V of high voltage (H) level is provided with the grid of MOS-FET (40) in output control through overdrive circuit (46) from rest-set flip-flop (45) lead-out terminal (Q) (Fig. 2) _S2After output control is with MOS-FET (40) conducting, from the 2nd output rectifier diode (15) of second subprime winding (5c), in the 2nd output smoothing capacitor (16) and load, flow through electric current, the voltage V of the 2nd output smoothing capacitor (16) through the 2nd rectifier smoothing circuit (17) _O2Rise.At this moment, in the stored energy, choke (100) has absorption, relaxes the effect that electric current sharply increases in choke (100).

When output control is turn-offed with MOS-FET (40),, therefore can reduce owing to connect the energy loss that choke (100) produces because the back electromotive force that is produced by choke (100) supplies to load by regeneration with diode (101).The electric current I that in the output rectifier diode of the 2nd shown in Figure 27 (F) (15), flows through _D2With the electric current I that flows through in the 2nd output rectifier diode (15) in the circuit that does not have choke (100) (not shown) _D2Compare, the electric current that do not shove suppresses to be step-down to peak current, prolong that electric current flows through during.The electric current I that in the 2nd output rectifier diode (15), flows through _D2Mean value also with in the past circuit is identical in this example, and according to whether peak current is arranged, power converter loss change is very big.Figure 28 and Figure 29 are expressions for the power converter efficient of the output power of circuit and circuit of the present invention in the past and for the curve chart of the characteristic of the output voltage of output current, solid line is represented the characteristic of this example, chain-dotted line is illustrated in the characteristic of having added the circuit of choke in the circuit in the past of copped wave with switch element is not set, dotted line represents not have the characteristic of copped wave with the circuit in the past of switch element and choke, and the characteristic of the present invention the 1st～the 16th example is represented in double dot dash line.In the circuit of the present invention the 1st who represents with double dot dash line～the 16th example, output voltage stabilization, but because peak current is big, power loss increases, therefore power converter efficient is low generally, particularly is accompanied by output power and increases, and power converter efficient reduces significantly.There do not have the circuit of representing with chain-dotted line in the past of current control unit only output power to be carried out rectification to be level and smooth, compare with the situation of the circuit in the past that does not have choke that dots, the low precision of output voltage is accompanied by the increase of output current, and output voltage reduces.In multi-output current-resonant type DC-DC converter of the present invention, though reduce with some efficient, but compare with the circuit of the present invention the 1st～the 16th example, improve power converter efficient significantly, particularly when big output power, compare with the situation that does not have chopper circuit, be improved to not a halfpenny the worse degree.

In the present invention, by current resonance choke based on the primary side leakage inductance (5d) of transformer (5), supply with the inductance of output control with the break-make copped wave action usefulness of MOS-FET (40), if therefore suppress peak current generation output current, then the copped wave of the leakage inductance (5d) that series connection is inserted in the elementary winding (5a) of transformer (5) action is very abundant, therefore the choke (100) that adds can be to suppress peak current in specific output, stops the small inductor of current concentration degree.On this basis, carry out with the choke (100) of the series reactor same function of chopper circuit owing to increase equivalently by the inductance of output control with the copped wave action of MOS-FET (40), therefore can be little more than needed inductance in the copped wave action in the past.

Generally using chopper circuit, is about 30 volts input voltage step-downs 24 volts, when output voltage takes place, need the inductance about 100 μ H (microhenry), and in multi-output current-resonant type DC-DC converter of the present invention shown in Figure 26, can use inductive choke coil (100) with MOS-FET (40) through output with 1 μ H.According to desired characteristic, need suitably select the inductance of choke, and in the present invention, can realize the characteristic that the choke with 1/100 inductance just can fully satisfy, installing restriction also seldom, the power loss that is produced by winding is also seldom.Thereby, in multi-output current-resonant type DC-DC converter of the present invention shown in Figure 26,, can suppress peak current, so power converter efficient does not reduce too owing to there is not the current concentration of primary side.

In addition, also can constitute output control circuit shown in Figure 26 (41) like that to Figure 30.Promptly, in the 18th example shown in Figure 30, be connected between pwm control circuit (44) in output control circuit shown in Figure 20 (41) and the drive circuit (46) after the 2nd detection signal has taken place voltage-change detecting circuit (42), keep the conducting of output control with MOS-FET (40), from the holding circuit till the regenerative current of choke (100) (102), do not omit regeneration shown in Figure 26 diode (101) up to.Be connected the high distolateral auxiliary power circuit that is made of rectifier diode (103) and smmothing capacitor (104) between the upper end of the upper end of second subprime winding (5c) and the 2nd output smoothing capacitor (16), the direct voltage that has moved the voltage between terminals part of the 2nd output smoothing capacitor (16) to high side's level supplies to holding circuit (102) and drive circuit (46) from the two ends of smmothing capacitor (104).Drive circuit (46) is roughly the same with structure shown in Figure 20, but between the base stage-collector electrode of PNP transistor (82), connect base resistance (92), the collector electrode of NPN transistor (81) is connected to the negative electrode of rectifier diode (103) and the tie point of smmothing capacitor (104), and the collector electrode of PNP transistor (82) is connected to the upper end this point difference of the 2nd output smoothing capacitor (16).Voltage-change detecting circuit (42) and pwm control circuit (44) are identical with structure shown in Figure 20.

Holding circuit (102) possesses: the divider resistance (105,106) that is connected in parallel for smmothing capacitor (70); Base stage is connected to the dividing point of divider resistance (105,106), and emitter is connected to the level translation transistor (107) of primary side ground connection terminal; The charging that between the tie point of level translation, is connected in series with the negative electrode of the collector electrode of transistor (107) and rectifier diode (103) and smmothing capacitor (104) with resistance (108) and discharge with resistance (109); For the maintenance capacitor (110) that discharges and be connected in parallel with resistance (109); Base stage is connected to charging with resistance (108) and the tie point of discharge with resistance (109), and the delay of the emitter negative electrode that is connected to rectifier diode (103) and the tie point of smmothing capacitor (104) drives and uses transistor (111).Postpone to drive the upper end that is connected to the biasing resistor (83) in the drive circuit (46) with the collector electrode of transistor (111).Equate up to the time of not flowing through regenerative current after the discharge time that keeps electrostatic capacitance value with capacitor (110) to be set at making when overdischarge electricity consumption resistance (109) discharge and the magnetization energy release end of choke (100).

The 1st detection signal V has taken place at voltage-change detecting circuit (42) _TDAfter, if the charging voltage V of the integrating condenser (77) in the pwm control circuit (44) _CWBecome and error voltage V _PCEquate, then from the output signal V of comparator (76) output HIGH voltage (H) level _PTThe output signal V of high voltage (H) level _PTBe provided to the base stage of level translation through the divider resistance (105,106) in the holding circuit (102) with crystal transistor (107), because level translation transistor (107) conducting, therefore the voltage that utilizes smmothing capacitor (104) is through the electricity consumption resistance (108) of overcharging, to keeping with capacitor (110) charging, simultaneously, the delay driving transistors (111) that flows through electric current between base-emitter switches to conducting.Thus, because NPN transistor (81) in the drive circuit (46) and PNP transistor (82) become conducting respectively and end, therefore output control switches to conducting with MOS-FET (40).At this moment, flow through electric current I in second subprime winding (5c), the 2nd output rectifier diode (15), the output control of transformer (5) in the path with MOS-FET (40), the 2nd output smoothing capacitor (16) and reactor (100) _D2, storage magnetization energy in choke (100).

If the polarity of the voltage that takes place in the second subprime winding (5c) of transformer (5) is anti-phase, the 2nd detection signal V takes place in voltage-change detecting circuit (42) _TD, then since the 2nd output rectifier diode (15) be reverse biased, therefore not from the second subprime winding (5c) of transformer (5) to the 2nd dc output end (18,19) supply capability.At this moment, because the second subprime winding (5c) from transformer (5) does not apply voltage to choke (100), therefore from choke (100) anti-phase electromotive force takes place, discharge magnetization energy, in the closed circuit that second subprime winding (5c), the 2nd output rectifier diode (15), output control by choke (100), transformer (5) form with MOS-FET (40) and the 2nd output smoothing capacitor (16), flow through regenerative current.Then, the discharge voltage V of the integrating condenser (77) in pwm control circuit (44) _CWWith error voltage V _PCAfter equating, from the output signal V of comparator (76) output LOW voltage (L) level _PTThe output signal V of low-voltage (L) level _PTBe provided to the base stage of level translation through the divider resistance (105,106) in the holding circuit (102),, therefore keep with capacitor (110) through overdischarge electricity consumption resistance (109) discharge because level translation ends with transistor (107) with transistor (107).After the magnetization energy release by choke (100) finishes no longer to flow through regenerative current, after the discharge end that keeps with capacitor (110), then do not flow through electric current between postponing to drive with the base-emitter of transistor (111), delay driving transistors (111) switches to and ends.Thus, end and conducting because NPN transistor (81) in the drive circuit (46) and PNP transistor (82) become respectively, therefore output control switches to shutoff with MOS-FET (40).

In Figure 30, after the 2nd detection signal taken place in voltage-change detecting circuit (42), since by holding circuit (102) keep output control with the conducting of MOS-FET (40) till the regenerative current that does not flow through from choke (100), therefore control with MOS-FET (40) through second subprime winding (5c), the 2nd output rectifier diode (15), the output of transformer (5), the magnetization energy that flows through in the 2nd output smoothing capacitor (16) by choke (100) discharges the regenerative current that produces, and the 2nd output smoothing capacitor (16) is charged.Promptly, regenerative current from choke (100) flows in the closed circuit that second subprime winding (5c), the 2nd output rectifier diode (15), output control by choke (100), transformer (5) form with MOS-FET (40), the 2nd output smoothing capacitor (16), therefore do not need regeneration shown in Figure 26 diode (101), compare with the 17th example, have the advantage that can constitute multi-output power supply at an easy rate.In addition, in Figure 30, according to the discharge time that keeps with capacitor (110), the constant time lag that output control is turn-offed with MOS-FET (40), and also can be by strengthening the resistance value of the interior discharge of pwm control circuit (44) with resistance (75), prolong integrating condenser (77) discharge time, the constant time lag that output control is turn-offed with MOS-FET (40).Discharge in this case can be set at the discharge voltage V of integrating condenser (77) with the resistance value of resistance (75) _CWError voltage V with the photosensitive unit (68b) of photoelectrical coupler (68) _PCThe time that becomes when equating equates up to the time of no longer flowing through regenerative current with the magnetization energy release end back of choke (100).

In multi-output current-resonant type DC-DC converter in the past shown in Figure 35, after the ac voltage rectifier smooth transformation of induction is direct voltage in the second subprime winding (5c) at transformer (5) by the 2nd rectifier smoothing circuit (17), be transformed to the 2nd VD V of the certain level that forces down than direct current once more by buck circuit (30) from the 2nd rectifier smoothing circuit (17) input _O2, therefore flow through big electric current in the smoothing choke (28) in buck circuit (30), thereby big power loss take place.Different therewith, in the present invention's the 17th example (Figure 26) and the 18th example (Figure 30), when MOS-FET (40) conducting is used in output control, the electric current that flows through with elementary winding (5a), leakage inductance (5d) and the 2nd main MOS-FET (2) of capacitor (4), transformer (5) along current resonance is through transformer (5), and is mobile in the closed circuit that is formed with MOS-FET (40), the 2nd output smoothing capacitor (16) and choke (100) by second subprime winding (5c), the 2nd output rectifier diode (15), output control.The electric current that flows through in this closed circuit is owing to leakage inductance (5d) restriction because of transformer (5), and choke (100) does not need the filter choke coil (28) of image pattern 35 to limit big electric current like that.Thereby the inductance of choke (100) therefore can use small-sized choke owing to little more than the filter choke coil (28) of Figure 35, and the power loss that is taken place is also few.In addition, when output control is turn-offed with MOS-FET (40), the inverse electromotive force that takes place in choke (100) by regeneration with diode (101) (Figure 26), perhaps the second subprime winding (5c) of transformer (5), the 2nd output rectification are used MOS-FET (40) (Figure 30) with diode (15) and output control, regeneration in the 2nd output smoothing capacitor (19), therefore compare with multi-output current-resonant type DC-DC converter in the past shown in Figure 35, have the high advantage of power converter efficient.

The invention is not restricted to the 1st～the 11st example, can also carry out various changes.For example, as shown in figure 17, even be connected the 2nd current resonance usefulness capacitor (90) with between the tie point of the leakage inductance (5d) of capacitor (4) and transformer (5) and the primary side earth terminal at current resonance shown in Figure 1, between the 2nd main MOS-FET (2) and drain electrode-source electrode, be connected the vibration of the 2nd voltage analog with capacitor (91), also can obtain effect and the effect roughly the same with the situation of Fig. 1.In the 2nd～the 4th example of Fig. 4～shown in Figure 6, also can be suitable for the change identical with circuit shown in Figure 17.In addition, as shown in figure 18, even be connected the 2nd current resonance usefulness capacitor (90) with between the tie point of the leakage inductance (5d) of capacitor (4) and transformer (5) and the primary side earth terminal at current resonance shown in Figure 7, between drain electrode-source electrode of the 2nd main MOS-FET (2), connect the vibration of the 2nd voltage analog with capacitor (91), also can obtain effect and the effect roughly the same with the situation of Fig. 7.Figure 11～the 6th～the 11st example shown in Figure 16 also can be suitable for the change identical with circuit shown in Figure 180.In addition, in the 1st～the 11st example, used the leakage inductance (5d) of transformer (5) as current resonance with inductance, and also can use external inductor.In addition, in the 1st～the 11st example, the conduction period of fixing the 1st main MOS-FET (1) and make the pulsewidth of the pulse signal of the variable frequency that conduction period of the 2nd main MOS-FET (2) changes modulate (PWM), and also can carry out fixed switching frequency and make the PWM control of the fixed frequency that each conduction period of the 1st and the 2nd main MOS-FET (1,2) changes.

In the 1st～the 11st example, take out the direct current output V of single polarity for a secondary winding (5b, 5c, 5g) of transformer (5) _O1, V _O2, V _O3, and also can take out positive and negative direct current output for a secondary winding (5b, 5c, 5g) of transformer (5).And then, in the 1st, the 5th and the 11st example at 2 output types, in the the the 2nd～the 4th, the 6th～the 8th and the 11st example, in the DC-DC of 3 output types converter, be suitable for the present invention, but be not limited to this situation, in DC-DC converter, also can be suitable for the present invention more than or equal to 4 output types.

In addition, in the 12nd example shown in Figure 19, also can be connected the 2nd current resonance capacitor with between the tie point of the leakage inductance (5d) of capacitor (4) and transformer (5) and the primary side earth terminal at current resonance, connection the 2nd voltage analog vibrates and uses capacitor between drain electrode-source electrode of the 2nd main MOS-FET (2).Available in this case effect and effect and Figure 19 are roughly the same.Change same as described above also can be useful in the 13rd～the 16th example of Figure 22～shown in Figure 25.In addition, in the 12nd～the 15th example, make each rectifier smoothing circuit (9,17) become the halfwave rectifier type that constitutes by an output rectifier diode (7,15) and an output smoothing capacitor (8,16), and also can constitute a certain side or both sides' rectifier smoothing circuit (9,17) with two ripple rectification types or full-wave bridge rectification type, and then can also make each structure of halfwave rectifier type, two ripple rectification types and full-wave bridge rectification type mix existence according to the load that is connected.

In addition, in the 12nd～the 16th example, be connected in parallel current resonance with the leakage inductance (5d) of capacitor (4), transformer (5) and the circuit that is connected in series of elementary winding (5a) for the 2nd main MOS-FET (2), and also can be for the 1st main MOS-FET (1) circuit that is connected in series that is connected in parallel.In addition, in the 12nd～the 16th example, the charging voltage V of the integrating condenser (77) in pwm control circuit (44) _CWError voltage V than the photosensitive unit (68b) of photoelectrical coupler (68) _PCWhen low, output control is switched to conducting with MOS-FET (40), as the discharge voltage V of integrating condenser (77) _CWError voltage V than the photosensitive unit (68b) of photoelectrical coupler (68) _PCWhen high, output control switched to shutoff with MOS-FET (40), and also can work as the discharge voltage V of integrating condenser (77) _CWError voltage V than the photosensitive unit (68b) of photoelectrical coupler (68) _PCWhen high, output control is switched to conducting with MOS-FET (40), the charging voltage V of the integrating condenser (77) in pwm control circuit (44) _CWError voltage V than the photosensitive unit (68b) of photoelectrical coupler (68) _PCWhen low, output control is switched to shutoff with MOS-FET (40).In the 12nd～the 16th example, between the drain-source of the 1st main MOS-FET (1), connect voltage analog vibration with capacitor (6), and also can between drain electrode-source electrode of the both sides of the 1st and the 2nd main MOS-FET (1,2) or a certain side, connect the simulation vibration with capacitor (6).

The 17th example can carry out various changes.For example, as shown in figure 31, can make the polarity of second subprime winding (5c) of transformer shown in Figure 26 (5) opposite.In addition, can be shown in figure 32, output shown in Figure 26 control is exchanged with the link position of choke (100) with MOS-FET (40), between the tie point of the negative electrode of the 2nd output rectifier diode (15) and choke (100) and the drain electrode of output control, being connected to regenerate and using diode (101) with MOS-FET (40).In addition, also can be as shown in figure 33, make the polarity of second subprime winding (5c) of transformer shown in Figure 32 (5) opposite.And then, also can be as shown in figure 34, output control shown in Figure 32 is altered to regeneration with the link position of MOS-FET (40) exports between the negative electrode of rectifier diode (15) with the tie point and the 2nd of diode (101) and choke (100).Under any situation of the circuit of Figure 31～shown in Figure 34, available effect and effect are all roughly the same with the 17th example.Particularly, under the situation of Figure 31 and circuit shown in Figure 33, owing to carry out alternately from first secondary winding (5b) of transformer (5) to the energy delivery of the 1st rectifier smoothing circuit (9) and from the second subprime winding (5c) of transformer (5) energy delivery to the 2nd rectifier smoothing circuit (17), therefore the utilization ratio height of transformer (5) can obtain bigger electric power with high efficiency.In addition, can also in each circuit of Figure 31～shown in Figure 34, use and the same change of the 18th example.That is,, then can omit each regeneration, constitute multi-output power supply at an easy rate with diode (101) if picture constitutes Figure 31～output control circuit (41) shown in Figure 34 as shown in Figure 30.

Can also vibrate the parasitic capacitance between the drain electrode-source electrode of the 1st and the 2nd main MOS-FET (1,2) as voltage analog and use with capacitor.In the 12nd～the 14th example, replace examining then by the variation in voltage in the output control circuit (41) circuit (42) detects the exciting voltage V that takes place in second subprime winding (5c) _T22Rising edge pulse and trailing edge pulse, also can detect the exciting voltage V of generation in first secondary winding (5b) of transformer (5) by the voltage-change detecting circuit (42) in the output control circuit (41) _T21Rising edge pulse and trailing edge pulse.And then, in the 12nd～the 17th example, illustration two direct currents output V are taking place _O1, V _O2Multi-output current-resonant type DC-DC converter in be suitable for example of the present invention, but be not limited to this situation, also can in the multi-output current-resonant type DC-DC converter that takes place more than or equal to three direct currents outputs, be suitable for the present invention.During the primary side supply capability during with the conducting of switch element, when shutoff is irrelevant.In addition, the mode of primary side rectifier system and single ripple rectification, full-wave rectification and two ripple rectifications is irrelevant.

Utilizability on the industry

The present invention can be applicable to the resonant type DC-DC that a plurality of direct current outputs take place well Converter for example, is applicable to the switch element and the generation that possess output control usefulness in primary side In the multi-output current-resonant type DC-DC converter of a plurality of direct current outputs.

Claims (9)

1. multi-output current-resonant type DC-DC converter has:

First switch element and the second switch element that are connected in series for DC power supply;

The current resonance that is connected in parallel for above-mentioned first switch element or second switch element is with the series circuit of the elementary winding of capacitor, inductor and transformer;

First rectifier smoothing circuit is connected in first secondary winding of above-mentioned transformer; And

Second rectifier smoothing circuit is connected in the second subprime winding of above-mentioned transformer,

By above-mentioned first and the on-off action of second switch element, flow through resonance current through above-mentioned current resonance with the elementary winding of capacitor, inductor, transformer and above-mentioned first switch element or second switch element, take out the output of first direct current from first secondary winding of above-mentioned transformer through above-mentioned first rectifier smoothing circuit, second subprime winding from above-mentioned transformer takes out the output of second direct current through above-mentioned second rectifier smoothing circuit simultaneously, and described multi-output current-resonant type DC-DC converter is characterised in that and comprises:

Switch element use in output control, is connected between the smmothing capacitor of the second subprime winding of above-mentioned transformer and above-mentioned second rectifier smoothing circuit of formation; And

Output control circuit based on the voltage of above-mentioned smmothing capacitor, is controlled the break-make of above-mentioned output control with switch element, wherein

Above-mentioned output control circuit possesses:

Voltage-change detecting circuit, the rising edge pulse of the voltage that detection takes place in any secondary winding of above-mentioned transformer, first detection signal takes place, detect the trailing edge pulse of the voltage that takes place in any secondary winding of above-mentioned transformer, second detection signal takes place;

Drive and Control Circuit after first detection signal or second detection signal have taken place above-mentioned voltage-change detecting circuit, switches to conducting or shutoff to above-mentioned output control respectively with switch element.

2. multi-output current-resonant type DC-DC converter according to claim 1 is characterized in that:

Above-mentioned output control circuit and above-mentioned first or the switching frequency of second switch element synchronously make above-mentioned output control switch element break-make.

3. multi-output current-resonant type DC-DC converter according to claim 1 and 2 is characterized in that above-mentioned Drive and Control Circuit comprises:

Error voltage generation circuit compares above-mentioned second direct current output error voltage of generation and their the corresponding level of error with reference voltage;

Integrated value corresponding first or second integral output with the voltage that takes place in any secondary winding of above-mentioned transformer after first or second detection signal has taken place above-mentioned voltage-change detecting circuit, take place in integrating circuit;

Comparator, above-mentioned error voltage and the output of above-mentioned first integral are compared, when above-mentioned first integral output is lower than above-mentioned error voltage, above-mentioned output control is switched to conducting with switch element, above-mentioned error voltage and the output of above-mentioned second integral are compared, when above-mentioned second integral output is higher than above-mentioned error voltage, above-mentioned output control is switched to shutoff with switch element.

4. multi-output current-resonant type DC-DC converter according to claim 3 is characterized in that:

Above-mentioned voltage-change detecting circuit possesses:

Detect and use switch element, the rising edge pulse of the voltage that detection takes place in any secondary winding of above-mentioned transformer, become conducting, first detection signal takes place, the trailing edge pulse of the voltage that detection takes place in any secondary winding of above-mentioned transformer, become shutoff, second detection signal takes place

Above-mentioned integrating circuit possesses:

Integrating condenser, above-mentioned first detection signal has taken place in above-mentioned detection with switch element after, the voltage that utilization takes place in any secondary winding of above-mentioned transformer charges, above-mentioned first integral output takes place, simultaneously above-mentioned second detection signal has taken place in above-mentioned detection with switch element after, the voltage that utilization takes place in any secondary winding of above-mentioned transformer discharges, and above-mentioned second integral output takes place

Above-mentioned comparator compares the charging/discharging voltage of above-mentioned error voltage and above-mentioned integrating condenser, when this charging/discharging voltage is lower than above-mentioned error voltage, above-mentioned output control is switched to conducting with switch element, when this charging/discharging voltage is higher than above-mentioned error voltage, above-mentioned output control is switched to shutoff with switch element.

5. multi-output current-resonant type DC-DC converter according to claim 1 and 2 is characterized in that above-mentioned Drive and Control Circuit comprises:

Error voltage generation circuit compares above-mentioned second direct current output error voltage of generation and their the corresponding level of error with reference voltage;

Integrated value corresponding first or second integral output with the voltage that takes place in any secondary winding of above-mentioned transformer after first or second detection signal has taken place above-mentioned voltage-change detecting circuit, take place in integrating circuit;

Comparator, above-mentioned error voltage and the output of above-mentioned first integral are compared, when above-mentioned first integral output is higher than above-mentioned error voltage, above-mentioned output control is switched to conducting with switch element, above-mentioned error voltage and the output of above-mentioned second integral are compared, when above-mentioned second integral output is lower than above-mentioned error voltage, above-mentioned output control is switched to shutoff with switch element.

6. multi-output current-resonant type DC-DC converter according to claim 5 is characterized in that:

Above-mentioned voltage-change detecting circuit possesses:

Detect and use switch element, the rising edge pulse of the voltage that detection takes place in any secondary winding of above-mentioned transformer, become conducting, first detection signal takes place, the trailing edge pulse of the voltage that detection takes place in any secondary winding of above-mentioned transformer, become shutoff, second detection signal takes place

Above-mentioned integrating circuit possesses:

Integrating condenser, above-mentioned first detection signal has taken place in above-mentioned detection with switch element after, the voltage that utilization takes place in any secondary winding of above-mentioned transformer charges, above-mentioned first integral output takes place, simultaneously above-mentioned second detection signal has taken place in above-mentioned detection with switch element after, the voltage that utilization takes place in any secondary winding of above-mentioned transformer discharges, and above-mentioned second integral output takes place

Above-mentioned comparator compares the charging/discharging voltage of above-mentioned error voltage and above-mentioned integrating condenser, when this charging/discharging voltage is higher than above-mentioned error voltage, above-mentioned output control is switched to conducting with switch element, when this charging/discharging voltage is lower than above-mentioned error voltage, above-mentioned output control is switched to shutoff with switch element.

7. multi-output current-resonant type DC-DC converter according to claim 1 is characterized in that:

Above-mentioned first and the both sides of second switch element or a certain side on be connected in parallel and be used for the capacitor of voltage analog resonance.

8. multi-output current-resonant type DC-DC converter has:

First switch element and the second switch element that are connected in series for DC power supply;

The current resonance that is connected in parallel for above-mentioned first switch element or second switch element is with the series circuit of the elementary winding of capacitor, inductor and transformer;

First rectifier smoothing circuit is connected in first secondary winding of above-mentioned transformer; And

Second rectifier smoothing circuit is connected in the second subprime winding of above-mentioned transformer,

By above-mentioned first and the on-off action of second switch element, flow through resonance current through above-mentioned current resonance with the elementary winding of capacitor, inductor, transformer and above-mentioned first switch element or second switch element, take out the output of first direct current from first secondary winding of above-mentioned transformer through above-mentioned first rectifier smoothing circuit, second subprime winding from above-mentioned transformer takes out the output of second direct current through above-mentioned second rectifier smoothing circuit simultaneously, and described multi-output current-resonant type DC-DC converter is characterised in that and comprises:

Switch element use in output control, is connected between the smmothing capacitor of the second subprime winding of above-mentioned transformer and above-mentioned second rectifier smoothing circuit of formation; And

Output control circuit based on the voltage of above-mentioned smmothing capacitor, is controlled the break-make of above-mentioned output control with switch element, wherein

Use in the formed closed-loop path of switch element in above-mentioned second subprime winding, above-mentioned second rectifier smoothing circuit and above-mentioned output control, be connected with choke,

After switch element (40) conducting is used in above-mentioned output control, voltage is applied on the leakage inductance (5d), this voltage is that the voltage from the magnetizing inductance (5e) of leakage inductance that is applied to above-mentioned transformer and above-mentioned transformer (5) deducts resulting voltage behind a certain voltage, the turn ratio that this a certain voltage equals elementary winding (5a) and second subprime winding (5c) multiply by the voltage of second subprime winding

Above-mentioned output control circuit comprises:

Voltage-change detecting circuit detects the voltage rising edge pulse that takes place in certain secondary winding of above-mentioned transformer and first detection signal takes place, and detect the voltage trailing edge pulse that takes place in certain secondary winding of transformer and second detection signal takes place, and

Drive and Control Circuit, after first detection signal takes place in above-mentioned voltage-change detecting circuit, above-mentioned output control is switched to conducting with switch element, after second detection signal takes place in above-mentioned voltage-change detecting circuit, when the back level does not connect holding circuit, above-mentioned output control is switched to shutoff with switch element, when the back level is connected with holding circuit, by holding circuit, turn-offing the constant time lag of above-mentioned output control with switch element.

9. multi-output current-resonant type DC-DC converter according to claim 8 is characterized in that:

Back level in above-mentioned Drive and Control Circuit has connected holding circuit, described holding circuit is after second detection signal has taken place in above-mentioned voltage-change detecting circuit, till the regenerative current from above-mentioned choke no longer flows through, keep the connection of above-mentioned output control with switch element.

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