CN100346561C - Switching type DC-DC converter with multiple output voltage - Google Patents

Abstract

The present invention relates to a switching type direct current to direct current converter which comprises multiple power supply channels, and an oscillator, wherein the multiple power supply channels are connected in parallel between a direct current voltage source and a ground, and used for converting a direct current voltage source into multiple direct current output voltage which is separated from each other; the oscillator outputs multiple oscillation signals. Thus, at least one switching transition is generated at different time points among the multiple power supply channels. Thereby, the instant noise is improved. The multiplex oscillation signals comprise two triangular wave oscillation signals of which the phase difference is 180DEG, and two pulse oscillation signals of which the phase difference is 180DEG. The rising edges of the two pulse oscillation signals are simultaneously generated respectively with the wave peak or the wave trough of the two triangular wave oscillation signals.

Description

Suitching type DC-DC converter with multiple output voltage

[technical field]

The present invention is about a kind of suitching type DC-DC converter, especially about a kind of suitching type DC-DC converter, be provided with the multiple power source supply passage so that multiple output voltage to be provided, can improve the transition noise (Transient Noise) that the power switching transistor is caused, wherein this multiple power source supply passage can all adopt voltage mode FEEDBACK CONTROL or a part of channel to adopt the voltage mode FEEDBACK CONTROL and remainder channel employing current-mode FEEDBACK CONTROL.

[prior art]

On the typical case, the suitching type DC-DC converter is reached by the duty cycle of power controlling switching transistor suitably direct voltage source is adjusted to the VD with desired voltage level.In the situation of voltage level greater than the voltage level of direct voltage source of VD, these suitching type DC-DC converter are collectively referred to as boost converter or boost pressure controller.On the other hand, in the situation of voltage level less than the voltage level of direct voltage source of VD, these suitching type DC-DC converter are collectively referred to as step-down controller or step down voltage redulator.In order to ensure the stability of VD, the suitching type DC-DC converter is typically provided with feedback circuit, and its type area is divided into voltage mode feedback and current-mode feedback.In the voltage mode feedback, the certain ratio of feedback circuit acquisition VD is in order to produce feedback signal.In the current-mode feedback, feedback circuit then utilizes the size of current sense amplifier detecting inductive current, so as to producing feedback signal.In addition, the current-mode feedback circuit also will capture the certain ratio of VD, in order to carry out the function of slope-compensation.

In most electronic system product now, operate and the result to reach a complete systematicness by combination functional module miscellaneous (Functional Module) usually.For example, digital camera be one by LCD, backlight module, image sensor, digital processing unit, with the electronic system product that many functional modules combined such as internal memory, thereby reach digitized video demonstration, picked-up, with store.In the example of digital camera, LCD, backlight module, image sensor, digital processing unit, all need direct current power supply can carry out desired operation and function with internal memory.On the typical case, the needed direct current power supply of functional module miscellaneous in the electronic system product is also inequality, that is is designed to separately operate under the different direct current power supply voltage.Because the electronic system product only has single direct voltage source usually, the voltage that battery provided for example is so must use a plurality of suitching type DC-DC converter so that supply a plurality of VD that differ from one another.Usually known to, a plurality of suitching type DC-DC converter are integrated in the single IC for both chip, thereby reduce encapsulation and distribution processing procedure, to reach low cost, small size and to reduce parasitic capacitance and the advantage of inductance.In this case, a plurality of power supply service ducts in the single IC for both chip after original a plurality of suitching type DC-DC converter is transformed into this and integrates.These a plurality of power supply service ducts are parallel between the common direct voltage source and ground, and the outlet terminal with each self-separation, in order to supply a plurality of VD that differ from one another.

Fig. 1 (a) shows existing circuit block diagram with suitching type DC-DC converter 10 of multiple output voltage.With reference to Fig. 1 (a), suitching type DC-DC converter 10 has four power supply service duct 11A to 11D, in order to single direct voltage source V _Source(being shown among Fig. 1 (b)) converts four VD V respectively to _Out1To V _Out4Power supply service duct 11A comprises a switch controller 12A, a change-over circuit 13A, is provided with a power switching transistor 15A and a feedback circuit 14A.Power switching transistor 15A is driven by pulse-width modulation (PWM) the control signal PWM1 that switch controller 12A is exported.The duty cycle of pwm control signal PWM1 has determined direct voltage source V _SourceWith VD V _Out1Between voltage level conversion relation.In other words, at fixing direct voltage source V _SourceCondition under, can handle VD V by the duty cycle of suitably adjusting pwm control signal PWM1 _Out1Voltage level.In addition, switch controller 12A receives the feedback signal FB1 that is produced from feedback circuit 14A, and adjusts the duty cycle of pwm control signal PWM1, makes VD V _Out1Be maintained at stable value.

Power supply service duct 11B comprises a switch controller 12B, a change-over circuit 13B, is provided with a power switching transistor 15B and a feedback circuit 14B.Power switching transistor 15B is driven by the pwm control signal PWM2 that switch controller 12B is exported.The duty cycle of pwm control signal PWM2 has determined direct voltage source V _SourceWith VD V _Out2Between voltage level conversion relation.Switch controller 12B receives the feedback signal FB2 that is produced from feedback circuit 14B, and adjusts the duty cycle of pwm control signal PWM2, makes VD V _Out2Be maintained at stable value.

Power supply service duct 11C comprises a switch controller 12C, a change-over circuit 13C, is provided with a power switching transistor 15C and a feedback circuit 14C.Power switching transistor 15C is driven by the pwm control signal PWM3 that switch controller 12C is exported.The duty cycle of pwm control signal PWM3 has determined direct voltage source V _SourceWith VD V _Out3Between voltage level conversion relation.Switch controller 12C receives the feedback signal FB3 that is produced from feedback circuit 14C, and adjusts the duty cycle of pwm control signal PWM3, makes VD V _Out3Be maintained at stable value.

Power supply service duct 11D comprises a switch controller 12D, a change-over circuit 13D, is provided with a power switching transistor 15D and a feedback circuit 14D.Power switching transistor 15D is driven by the pwm control signal PWM4 that switch controller 12D is exported.The duty cycle of pwm control signal PWM4 has determined direct voltage source V _SourceWith VD V _Out4Between voltage level conversion relation.Switch controller 12D receives the feedback signal FB4 that is produced from feedback circuit 14D, and adjusts the duty cycle of pwm control signal PWM4, makes VD V _Out4Be maintained at stable value.

Oscillator 16 output pulse signal PULSE1 and ramp signal RAMP1 are to switch controller 12A.The rising edge of pulse signal PULSE1 takes place simultaneously along the trailing edge edge with ramp signal RAMP1.Pulse signal PULSE1 is provided with (Set) switch controller 12A, the rising edge edge that makes it to produce pwm control signal PWM1, and then conducting power switching transistor 15A.The generation on the trailing edge edge of ramp signal RAMP1 and feedback signal FB1 decision pwm control signal PWM1, and then close power switching transistor 15A.Oscillator 16 is gone back output pulse signal PULSE2 and ramp signal RAMP2 to switch controller 12B.The rising edge of pulse signal PULSE2 takes place simultaneously along the trailing edge edge with ramp signal RAMP2.Pulse signal PULSE2 is provided with switch controller 12B, makes it to produce the rising edge edge of pwm control signal PWM2, and then conducting power switching transistor 15B.The generation on the trailing edge edge of ramp signal RAMP2 and feedback signal FB2 decision pwm control signal PWM2, and then close power switching transistor 15B.Oscillator 16 is gone back output pulse signal PULSE3 and ramp signal RAMP3 again to switch controller 12C.The rising edge of pulse signal PULSE3 takes place simultaneously along the trailing edge edge with ramp signal RAMP3.Pulse signal PULSE3 is provided with switch controller 12C, makes it to produce the rising edge edge of pwm control signal PWM3, and then conducting power switching transistor 15C.The generation on the trailing edge edge of ramp signal RAMP3 and feedback signal FB3 decision pwm control signal PWM3, and then close power switching transistor 15C.Oscillator 16 is gone back output pulse signal PULSE4 and ramp signal RAMP4 again to switch controller 12D.The rising edge of pulse signal PULSE4 takes place simultaneously along the trailing edge edge with ramp signal RAMP4.Pulse signal PULSE4 is provided with switch controller 12D, makes it to produce the rising edge edge of pwm control signal PWM4, and then conducting power switching transistor 15D.The generation on the trailing edge edge of ramp signal RAMP4 and feedback signal FB4 decision pwm control signal PWM4, and then close power switching transistor 15D.

With reference to Fig. 1 (b), power supply service duct 11A to 11D is connected in parallel to each other in direct voltage source V _SourceAnd between the ground.Particularly, power supply service duct 11A to 11D is parallel to direct voltage source V via connecting distribution _SourceAnd between the ground.As a result, at direct voltage source V _SourceBe connected the stray inductance L that distribution causes with having respectively between power supply service duct 11A to 11D _wSimilarly, between power supply service duct 11A to 11D and ground, also have respectively and be connected the stray inductance L that distribution causes _wIn the operation of power supply service duct 11A to 11D, the power switching transistor 15A to 15D among the change-over circuit 13A to 13D periodically switches, thereby reaches the function of voltage transitions.Because stray inductance L _wExistence, when any of power switching transistor 15A to 15D switched transition, promptly produce the noise that is caused by transition spike (Transient Spike).

Pulse signal PULSE1 to PULSE4 that the existing oscillator 16 of Fig. 1 (c) demonstration is produced and the waveform sequential chart of ramp signal RAMP1 to RAMP4.Shown in Fig. 1 (c), pulse signal PULSE1 to PULSE4 has identical waveform and phase place each other, and ramp signal RAMP1 to RAMP4 has identical waveform and phase place each other.Therefore, oscillator 16 in fact only need produce single pulse signal and single ramp signal, is supplied to the switch controller 12A to 12D of four power supply service duct 11A to 11D to get final product subsequently simultaneously.In the prior art, the circuit configurations of oscillator 16 get quite simple, have small size and advantage cheaply.Yet synchronous pulse signal PULSE1 to PULSE4 is provided with switch controller 12A to 12D simultaneously, makes power switching transistor 15A to the 15B transition that switch simultaneously.As a result, the transition spike mutual superposition that each caused of power switching transistor 15A to 15B.Therefore, direct voltage source V _SourceAnd have sizable transition noise between the ground, make VD V _Out1To V _Out4Quality worsen and cause easily the damage of power supply service duct 11A to 11D.

[summary of the invention]

Because foregoing problems, a purpose of the present invention is to provide a kind of suitching type DC-DC converter, has multiple output voltage, the transition spike mutual superposition that can avoid the multiple power source supply passage to be caused, and the operation of reaching low relatively transition noise.

Another object of the present invention is to provide a kind of suitching type DC-DC converter, have multiple output voltage, can be by using the simple oscillator of configuration, to reach small size and advantage cheaply.

According to an aspect of of the present present invention, a kind of suitching type DC-DC converter is provided, comprise: one first power supply service duct, be coupled between a direct current voltage source and the ground, become one first VD in order to change this direct voltage source; One second source service duct is coupled between this direct voltage source and the ground, becomes one second VD in order to change this direct voltage source, and this second VD and this first VD are separated; An and oscillator, one first oscillator signal that has a period 1 in order to output is to this first power supply service duct, and has one second oscillator signal of a second round to this second source service duct in order to output, wherein: in each cycle of this period 1, this first oscillator signal has a crest, one trough, increase to a rising part of this crest gradually from this trough, and be gradually reduced to a decline part of this trough from this crest, make the switching transition of this first power supply service duct betide in this rising part and one of them time range that is contained of this sloping portion of this first oscillator signal; In each cycle of this second round, this second oscillator signal has the edge of transition in a flash, one of them takes place this crest of the edge of these moment transition and this first oscillator signal and this trough simultaneously, makes the switching transition system of this second source service duct and the edge of these moment transition take place simultaneously.

Preferably, this oscillator is also exported one first auxiliary signal to this second source service duct, wherein this first auxiliary signal is an oblique wave oscillator signal, has a rising part and a decline edge, makes this trailing edge edge and the edge of these moment transition of this second oscillator signal take place simultaneously.

Preferably, the suitching type DC-DC converter, also comprise: one the 3rd power supply service duct, be coupled between this direct voltage source and the ground, become one the 3rd VD in order to change this direct voltage source, the 3rd VD and this first is separated with this second VD, wherein: this oscillator also export have a period 3 one the 3rd oscillator signal to the 3rd power supply service duct; In each cycle of this period 3, the 3rd oscillator signal has a crest, a trough, increases to a rising part of this crest and a decline part that is gradually reduced to this trough from this crest gradually from this trough, make this crest of the 3rd oscillator signal and this trough of this first oscillator signal take place simultaneously, and this crest of this trough of the 3rd oscillator signal and this first oscillator signal take place simultaneously; And at least one switching transition of the 3rd power supply service duct betide in this rising part of the 3rd oscillator signal and the time range that this sloping portion is contained.

Preferably, this suitching type DC-DC converter also comprises: one the 4th power supply service duct, be coupled between this direct voltage source and the ground, become one the 4th VD in order to change this direct voltage source, the 4th VD and this first is separated with this second VD, wherein: this oscillator also export have a period 4 one the 4th oscillator signal to the 4th power supply service duct; In each cycle of this period 4, the 4th oscillator signal has the edge of transition in a flash, and one of them takes place edge that wherein should the moment transition and this crest of this first oscillator signal and this trough simultaneously; Have preset time skew between the edge of the edge of these moment transition of the 4th oscillator signal and these moment transition of this second oscillator signal; And the edge of at least one switching transition of the 4th power supply service duct and these moment transition of the 4th oscillator signal takes place simultaneously.

Preferably, this oscillator is also exported one second auxiliary signal to the 4th power supply service duct, wherein this second auxiliary signal is an oblique wave oscillator signal, has a rising part and a decline edge, makes this trailing edge edge and the edge of these moment transition of the 4th oscillator signal take place simultaneously.

According to another aspect of the present invention, a kind of oscillator is provided, comprise: one installs, and has one first oscillator signal of a period 1 in order to output; And one the device, one second oscillator signal that has a second round in order to output, wherein: in each cycle of this period 1, this first oscillator signal has a crest, a trough, increases to a rising part of this crest and a decline part that is gradually reduced to this trough from this crest gradually from this trough; And in each cycle of this second round, this second oscillator signal has the edge of transition in a flash, and one of them takes place edge that wherein should the moment transition and this crest of this first oscillator signal and this trough simultaneously.

Preferably, this first oscillator signal is a triangular wave oscillation signal.

Preferably, this second oscillator signal is an impulse oscillation signal, in each cycle of this second round, have rising edge edge, a pulse duration, with a decline edge, and the edge of these moment transition of this second oscillator signal is meant its this rising edge edge.

Preferably, this oscillator also comprises: a device, and in order to export one first auxiliary signal, wherein this first auxiliary signal is an oblique wave oscillator signal, have a rising part and a decline edge, make this trailing edge edge and the edge of these moment transition of this second oscillator signal take place simultaneously.

Preferably, this oscillator also comprises: a device, one the 3rd oscillator signal that has a period 3 in order to output, wherein: in each cycle of this period 3, the 3rd oscillator signal has a crest, a trough, increases to a rising part of this crest and a decline part that is gradually reduced to this trough from this crest gradually from this trough, make this crest of the 3rd oscillator signal and this trough of this first oscillator signal take place simultaneously, and this crest of this trough of the 3rd oscillator signal and this first oscillator signal take place simultaneously.

Preferably, the 3rd oscillator signal is the inversion signal of this first oscillator signal.

Preferably, this oscillator also comprises: a device, one the 4th oscillator signal that has a period 4 in order to output, wherein: in each cycle of this period 4, the 4th oscillator signal has the edge of transition in a flash, one of them takes place edge that wherein should the moment transition and this crest of this first oscillator signal and this trough simultaneously, and has preset time skew between the edge of these moment transition of the edge of these moment transition of the 4th oscillator signal and this second oscillator signal.

Preferably, the 4th oscillator signal is an impulse oscillation signal, in each cycle of this period 4, have rising edge edge, a pulse duration, with a decline edge, and the edge of these moment transition of the 4th oscillator signal is meant its this rising edge edge.

Preferably, this oscillator also comprises: a device, and in order to export one second auxiliary signal, wherein this second auxiliary signal is an oblique wave oscillator signal, have a rising part and a decline edge, make this trailing edge edge and the edge of these moment transition of the 4th oscillator signal take place simultaneously.

In according to the suitching type DC-DC converter with multiple output voltage of the present invention, at least one switching transition of this of this first to the 4th power supply service duct take place in time separated from one anotherly, can avoid transition spike mutual superposition, and reach the mode of operation of low relatively transition noise.In addition, adopt according to the suitching type DC-DC converter with multiple output voltage of the present invention and to use the simple oscillator of configuration, produce many synchronous waveform of leggy signal, thereby reach small size and advantage cheaply.Should notice that the foundation suitching type DC-DC converter with multiple output voltage of the present invention can be applicable to have the power supply service duct of arbitrary number.

[description of drawings]

Explanation hereinafter and accompanying drawing will make aforementioned and other purpose of the present invention, feature, more obvious with advantage.Hereinafter with reference to the preferred embodiment of the present invention of graphic detailed description foundation.

Fig. 1 (a) shows existing circuit block diagram with suitching type DC-DC converter of multiple output voltage.

Fig. 1 (b) shows the stray inductance that the connection distribution between direct voltage source and the ground is caused.

Fig. 1 (c) shows the waveform sequential chart of the signal that existing oscillator is produced.

Fig. 2 (a) shows according to the circuit block diagram with suitching type DC-DC converter of multiple output voltage of the present invention.

Fig. 2 (b) shows the sequential chart of the signal of being exported according to many synchronous waveform of leggy oscillator of the present invention.

Fig. 3 shows the detailed circuit diagram according to multiple power source supply passage of the present invention.

Fig. 4 shows the circuit block diagram according to many synchronous waveform of leggy oscillator of the present invention.

Fig. 5 shows the detailed circuit diagram according to first example of many synchronous waveform of leggy oscillator of the present invention.

Fig. 6 shows the detailed circuit diagram according to second example of many synchronous waveform of leggy oscillator of the present invention.

[embodiment]

Before describing in detail according to embodiments of the invention, understand in order to make the easier quilt of technical characterictic of the present invention, difference with the prior art of the present invention at first is described.According to suitching type DC-DC converter and the United States Patent (USP) the 5th with multiple output voltage of the present invention, 959, No. 441, the 6th, 137, No. 274, the 6th, 144, No. 194, with the 6th, leggy suitching type DC-DC converter described in the prior art such as 246, No. 222 is also inequality.Particularly, the leggy suitching type DC-DC converter of prior art only is provided with single output to supply single the output voltage after the adjusting, yet then be provided with a plurality of outputs according to suitching type DC-DC converter of the present invention, separated from one another, thus output voltage after a plurality of adjustings supplied respectively.Moreover it is even that the leggy suitching type DC-DC converter of prior art must be devoted to keep the electric current that a plurality of power supply service ducts circulate to each other, takes place to avoid " passage of heat (Hot Channel) " phenomenon.Yet according in the suitching type DC-DC converter of the present invention, a plurality of power supply service ducts are output voltages of supplying discretely after a plurality of adjustings.In addition, the oscillator in the leggy suitching type DC-DC converter of prior art only limits to provide the have same waveform as pulse signal and the ramp signal of (may have out of phase).Yet in foundation suitching type DC-DC converter of the present invention, the oscillator signal of oscillator output different wave out of phase is to each power supply service duct of operation independently of one another.More and, each power supply service duct in the leggy suitching type DC-DC converter of prior art must adopt identical feedback mode control.Yet in foundation suitching type DC-DC converter of the present invention, each power supply service duct can use different feedback mode controls.

Hereinafter describe method in detail according to the transition noise of the suitching type DC-DC converter 20 with multiple output voltage of improvement of the present invention with reference to Fig. 2 (a) and 2 (b) and Fig. 3.

Fig. 2 (a) shows according to the circuit block diagram with suitching type DC-DC converter 20 of multiple output voltage of the present invention.In order to prevent graphic overcomplicated and the easier quilt of technical characterictic of the present invention to be understood, graphic only demonstration of Fig. 2 (a) and explanation hereinafter and other reference has the suitching type DC-DC converter 20 of four output voltages, as one embodiment of the invention.Should note the invention is not restricted to this embodiment, and can be applicable to have the suitching type DC-DC converter of the output voltage of arbitrary number.Hereinafter will describe the suitching type DC-DC converter 20 of the present invention of the foundation shown in Fig. 2 (a) in detail and be different from the prior art part shown in Fig. 1 (a).

With reference to Fig. 2 (a), suitching type DC-DC converter 20 is different from suitching type DC-DC converter 10 parts shown in Fig. 1 (a) and is that suitching type DC-DC converter 20 is provided with many synchronous waveform of leggy oscillator 26, is used to replace the oscillator 16 of prior art.Particularly, many synchronous waveform of leggy oscillator 26 can produce the synchronized oscillation signal of a plurality of outs of phase and different wave.In the embodiment shown in Fig. 2 (a), synchronous oscillator signal TR1, TR2, PC1 and the PC2 of many synchronous waveform of leggy oscillator 26 outputs, it has different phase places and different waveforms, is sent to the switch controller 22A to 22D of power supply service duct 21A to 21D respectively.In addition, auxiliary signal RM1 also is accompanied by oscillator signal PC1 input switch controller 22C, and auxiliary signal RM2 also is accompanied by oscillator signal PC2 input switch controller 22D.By synchronous oscillator signal TR1, TR2, PC1, with phase difference and the different wave shape of PC2, switch controller 22A to 22D can make power switching transistor 25A to the 25D transition that switch at different time points, thereby avoids transition spike mutual superposition.

Fig. 2 (b) show oscillator signal TR1, TR2, PC1, with the sequential chart of PC2 and auxiliary signal RM1 and RM2, in order to clearly demonstrate its phase relation and wave character to each other.With reference to Fig. 2 (b), oscillator signal TR1 is a continuous triangular wave, and its amplitude variations is in V _H(being referred to as peak value) and V _LBetween (being referred to as valley).Similarly, oscillator signal TR2 is another continuous triangular wave, and its amplitude also changes in V _HWith V _LBetween.The waveform of oscillator signal TR1 and TR2 for convenience of description, " crest " is meant that amplitude equals peak value V _H, " trough " is meant that amplitude equals valley V _L, " rising part " is meant that amplitude is from valley V _LIncrease to peak value V gradually _H, and " sloping portion " is meant that amplitude is from peak value V _HBe gradually reduced to valley V _LOscillator signal TR1 has the identical cycle with TR2 but phase place differs 180 degree, make the crest of oscillator signal TR1 aim at the trough of oscillator signal TR2 in time, and the trough of oscillator signal TR1 is aimed at the crest of oscillator signal TR2 in time.In other words, the rising part of oscillator signal TR1 and TR2 staggers each other in time, does not overlap each other.Similarly, the sloping portion of oscillator signal TR1 and TR2 staggers each other in time, does not overlap each other.Though note that in the embodiment shown in Fig. 2 (b), oscillator signal TR1 has the peak value of identical size and the valley of identical size with TR2, the invention is not restricted to this.In another embodiment of the present invention, oscillator signal TR1 can have the peak value of different sizes or the valley of different sizes with TR2.Moreover, though in the embodiment shown in Fig. 2 (b), oscillator signal TR1 and TR2 are all the equilateral triangle ripple that shared time of rising part and shared time of sloping portion are equal to each other, but the invention is not restricted to this, and can be applicable to oscillator signal TR1 and TR2 is all shared time of rising part and unequal each other non-equilateral triangle ripple of shared time of sloping portion.Moreover though in the embodiment shown in Fig. 2 (b), the rising part of oscillator signal TR1 and TR2 is all linear increasing, and the invention is not restricted to this, and the rising part that can be applicable to oscillator signal TR1 and TR2 is all non-linear increase.Moreover though in the embodiment shown in Fig. 2 (b), the sloping portion of oscillator signal TR1 and TR2 is all linear the minimizing, the invention is not restricted to this, and the sloping portion that can be applicable to oscillator signal TR1 and TR2 is all non-linear minimizing.

Oscillator signal PC1 is a pulse signal, wherein each pulse by the rising edge from LOW (low) moment transition to HIGH (height) along, be maintained at HIGH pulse duration, form along institute with trailing edge from LOW moment transition to HIGH.Auxiliary signal RM1 is a continuous oblique wave, by increasing to maximum V gradually from 0 _MaxRising part with from maximum V _MaxThe trailing edge of moment transition to 0 along form.The rising edge of oscillator signal PC1 takes place simultaneously along the trailing edge edge with auxiliary signal RM1.Oscillator signal PC2 is a pulse signal, wherein each pulse by the rising edge from LOW moment transition to HIGH along, be maintained at HIGH pulse duration, form along institute with trailing edge from LOW moment transition to HIGH.Auxiliary signal RM2 is a continuous oblique wave, by increasing to maximum V gradually from 0 _MaxRising part with from maximum V _MaxThe trailing edge of moment transition to 0 along form.The rising edge of oscillator signal PC2 takes place simultaneously along the trailing edge edge with auxiliary signal RM2.In addition, shown in Fig. 2 (b), oscillator signal PC1 has the identical cycle with PC2 but phase place differs 180 degree.Though note that in the embodiment shown in Fig. 2 (b) the maximum V that oscillator signal PC1 and PC2 have identical size _Max, but the invention is not restricted to this.In another embodiment of the present invention, oscillator signal PC1 can have the maximum of different sizes with PC2, but still need keep the phase difference of identical cycle and 180 degree to each other.

In the embodiment shown in Fig. 2 (b), peak value V _HBe about 0.8 volt, and valley V _LBe about 0.3 volt.Oscillator signal TR1, TR2, PC1, all be about 1 microsecond with cycle of PC2 and auxiliary signal RM1 and RM2.The width of the pulse of oscillator signal PC1 and PC2 is about 100 nanoseconds, and state HIGH is about 2.2 volts and state LOW is about 0 volt.The amplitude maximum V of auxiliary signal RM1 and RM2 _MaxBe about 0.8 volt.

Clearly visible from Fig. 2 (b), the crest of the trough of oscillator signal TR1, oscillator signal TR2, the rising edge of oscillator signal PC1 along, with the trailing edge of auxiliary signal RM1 along being to take place simultaneously.Moreover, the trough of the crest of oscillator signal TR1, oscillator signal TR2, the rising edge of oscillator signal PC2 along, with the trailing edge of auxiliary signal RM2 along being to take place simultaneously.

Fig. 3 shows the detailed circuit diagram according to power supply service duct 21A to 21D of the present invention.With reference to Fig. 3, power supply service duct 21A adopts the voltage mode FEEDBACK CONTROL, operates in response to oscillator signal TR1, in order to conversion dc voltage source V _SourceBecome VD V _Out1Power supply service duct 21A comprises a switch controller 22A, a change-over circuit 23A and a feedback circuit 24A.Change-over circuit 23A is a decompression converting circuit, have power switching transistor 25A, inductance L 1, capacitor C 1, with diode D1, as coupling as graphic.Feedback circuit 24A provides an indication VD V by the bleeder circuit that resistance R a1 and Rb1 are formed _Out1Feedback signal FB1.Error amplifier EA1 among the feedback signal FB1 input switch controller 22A makes it to be compared to reference voltage V _Ref1Subsequently, PWM comparator PA1 exports the comparative result of the error voltage that oscillator signal TR1 and error amplifier EA1 are exported to driver DR1, thereby produce pwm control signal PWM1, in order to drive the power switching transistor 25A that is implemented by nmos pass transistor Q1.Particularly, when oscillator signal TR1 is gradually reduced to the moment that equals error voltage from peak value, PWM comparator PA1 makes pwm control signal PWM1 transition that driver DR1 exports for enabling (enable) state (being HIGH in the present embodiment), with conducting nmos pass transistor Q1.Subsequently, when oscillator signal TR1 increases to the moment that equals error voltage once more gradually from valley, PWM comparator PA1 makes pwm control signal PWM1 transition that driver DR1 exports for not enabling (unable) state (being LOW in the present embodiment), to close nmos pass transistor Q1.

Power supply service duct 21B adopts the voltage mode FEEDBACK CONTROL, operates in response to oscillator signal TR2, in order to conversion dc voltage source V _SourceBecome VD V _Out2Power supply service duct 21B comprises a switch controller 22B, a change-over circuit 23B and a feedback circuit 24B.Change-over circuit 23B is a decompression converting circuit, have power switching transistor 25B, inductance L 2, capacitor C 2, with diode D2, as coupling as graphic.The bleeder circuit of feedback circuit 24B for being made up of resistance R a2 and Rb2 provides an indication VD V _Out2Feedback signal FB2.Error amplifier EA2 among the feedback signal FB2 input switch controller 22B makes it to be compared to reference voltage V _Ref2Subsequently, PWM comparator PA2 exports the comparative result of the error voltage that oscillator signal TR2 and error amplifier EA2 are exported to driver DR2, thereby produce pwm control signal PWM2, in order to drive the power switching transistor 25B that is implemented by nmos pass transistor Q2.Particularly, when oscillator signal TR2 is gradually reduced to the moment that equals error voltage from peak value, the pwm control signal PWM2 transition that PWM comparator PA2 exports driver DR2 are enabled state (being HIGH in the present embodiment), with conducting nmos pass transistor Q2.Subsequently, when oscillator signal TR2 increases to the moment that equals error voltage once more gradually from valley, PWM comparator PA2 makes pwm control signal PWM2 transition that driver DR2 exports be enabled state (being LOW in the present embodiment) not, to close nmos pass transistor Q2.

Power supply service duct 21C adopts the voltage mode FEEDBACK CONTROL, operates in response to oscillator signal PC1 and auxiliary signal RM1, in order to conversion dc voltage source V _SourceBecome VD V _Out3Power supply service duct 21C comprises a switch controller 22C, a change-over circuit 23C and a feedback circuit 24C.Change-over circuit 23C is a decompression converting circuit, have power switching transistor 25C, inductance L 3, capacitor C 3, with diode D3, as coupling as graphic.Feedback circuit 24C provides an indication VD V by the bleeder circuit that resistance R a3 and Rb3 are formed _Out3Feedback signal FB3.Error amplifier EA3 among the feedback signal FB3 input switch controller 22C makes it to be compared to reference voltage V _Ref3And export an error voltage to PWM comparator PA3.Particularly, oscillator signal PC1 is in order to latch unit LA1 to be set, and the pwm control signal PWM3 transition that driver DR3 is exported are enabled state (being HIGH in the present embodiment), the power switching transistor 25C that is implemented by nmos pass transistor Q3 with conducting.On the other hand, because the trailing edge of auxiliary signal RM1 along with the rising edge of oscillator signal PC1 along taking place simultaneously, so the trailing edge of auxiliary signal RM1 is along also taking place simultaneously with the conducting of nmos pass transistor Q3.Subsequently, when the rising part of auxiliary signal RM1 increases to the moment that equals error voltage gradually, PWM comparator PA3 replacement latch unit LA1 makes pwm control signal PWM3 transition that driver DR3 exports be enabled state (being LOW in the present embodiment) not, to close nmos pass transistor Q3.

Power supply service duct 21D adopts the current-mode FEEDBACK CONTROL, operates in response to oscillator signal PC2 and auxiliary signal RM2, in order to conversion dc voltage source V _SourceBecome VD V _Out4Power supply service duct 21D comprises a switch controller 22D, a change-over circuit 23D and a feedback circuit 24D.Change-over circuit 23D is a decompression converting circuit, have power switching transistor 25D, inductance L 4, series resistance Rs, capacitor C 4, with diode D4, as coupling as graphic.Feedback circuit 24D comprises a current sense amplifier CA, and in order to feedback signal FB4 to be provided, its indication is crossed the potential difference that series resistance Rs is caused by inductive current.In addition, in order to carry out the slope-compensation of current-mode FEEDBACK CONTROL, feedback circuit 24D can also include a bleeder circuit of being made up of resistance R a4 and Rb4, and an indication VD V is provided _Out4Signal to error amplifier EA4, make it to be compared to reference voltage V _Ref4By analog operational circuit AD, after the error voltage that error amplifier EA4 is exported deducts auxiliary signal RM2, the end of oppisite phase of input PWM comparator PA4.The non-oppisite phase end of feedback signal FB4 input PWM comparator PA4.Oscillator signal PC2 is in order to be provided with latch unit LA2, and the pwm control signal PWM4 transition that driver DR4 is exported are enabled state (being HIGH in the present embodiment), the power switching transistor 25D that is implemented by nmos pass transistor Q4 with conducting.Because the trailing edge of auxiliary signal RM2 along with the rising edge of oscillator signal PC2 along taking place simultaneously, so the trailing edge of auxiliary signal RM2 is along also taking place simultaneously with the conducting of nmos pass transistor Q4.During nmos pass transistor Q4 conducting, inductive current increases the feedback signal FB4 that causes current sense amplifier CA to be exported linearly and increases linearly.Increase to the moment that equals the voltage that analog operational circuit exports as feedback signal FB4, PWM comparator PA4 replacement latch unit LA2, make pwm control signal PWM4 transition that driver DR4 exports be enabled state (being LOW in the present embodiment) not, to close nmos pass transistor Q4.

From the explanation of preamble as can be known, power switching transistor 25A is the sloping portion that is positioned at oscillator signal TR1 from closing transition to the time point of conducting, and power switching transistor 25B then is positioned at the sloping portion of oscillator signal TR2 from closing transition to the time point of conducting.Because the sloping portion of oscillator signal TR1 and TR2 is gone up non-overlapping copies in the time each other, shown in Fig. 2 (b), so prevent that effectively power switching transistor 25A and 25B are simultaneously from closing transition to conducting.As a result, the transition spike that caused of power switching transistor 25A and 25B can mutual superposition.

On the other hand, power switching transistor 25C from close transition to the rising edge of conducting system and oscillator signal PC1 along taking place simultaneously, power switching transistor 25D from close transition to conducting then with the rising edge of oscillator signal PC2 along taking place simultaneously.Because the rising edge of oscillator signal PC1 and PC2 is along non-overlapping copies in time each other, shown in Fig. 2 (b), so prevent that effectively power switching transistor 25C and 25D are simultaneously from closing transition to conducting.As a result, the transition spike that caused of power switching transistor 25C and 25D can mutual superposition.

In addition, clearly visible from Fig. 2 (b), since the rising edge of oscillator signal PC1 is along taking place simultaneously with the trough of oscillator signal TR1 and the crest of oscillator signal TR2, so the rising edge of oscillator signal PC1 is along not being positioned at oscillator signal TR1 and TR2 sloping portion separately.As a result, power switching transistor 25C is different from power switching transistor 25A and 25B from closing the time point of transition to conducting from closing transition to the time point of conducting.Similarly, since the rising edge of oscillator signal PC2 is along taking place simultaneously with the crest of oscillator signal TR1 and the trough of oscillator signal TR2, so the rising edge of oscillator signal PC2 is along not being positioned at oscillator signal TR1 and TR2 sloping portion separately.As a result, power switching transistor 25D is different from power switching transistor 25A and 25B from closing the time point of transition to conducting from closing transition to the time point of conducting.Thereby in foundation suitching type DC-DC converter 20 of the present invention, the transition spike that power switching transistor 25A to 25D is caused can mutual superposition.

Please note, though in the embodiment shown in fig. 3, power supply service duct 21A to 21C is all the voltage mode FEEDBACK CONTROL and power supply service duct 21D is a Current Feedback Control, but the invention is not restricted to this, to be all the situation of voltage mode FEEDBACK CONTROL or power supply service duct 21A and 21B be voltage mode FEEDBACK CONTROL and power supply service duct 21C and 21D are the situation of Current Feedback Control and can be applicable to power supply service duct 21A to 21D.

Please note, though in the embodiment shown in fig. 3, power switching transistor 25A to 25D is from closing the time point non-overlapping copies of transition to conducting, but the invention is not restricted to this, and can be applicable to power switching transistor 25A to 25D from the conducting transition to the time point non-overlapping copies of closing.In other words, according to the present invention, at least one switching transition of power switching transistor 25A to 25D are non-overlapping copies in time, wherein switch transition be meant from close transition to conducting or from the conducting transition to closing.

Fig. 4 shows the circuit block diagram according to many synchronous waveform of leggy oscillator 26 of the present invention.With reference to Fig. 4, many synchronous waveform of leggy oscillator 26 comprises an oscillator signal generator 41, an inverter 42 and an auxiliary signal generator 43.Particularly, oscillator signal generator 41 produces oscillator signal TR1.Subsequently, oscillator signal TR2 is by obtaining from oscillator signal TR1 via inverter 42.As a result, oscillator signal TR1 spends with the phasic difference mutually 180 of TR2.Except oscillator signal TR1, oscillator signal generator 41 also produces the oscillator signal PC1 and the PC2 of two phase phasic differences, 180 degree.At last, in response to oscillator signal PC1 and PC2, auxiliary signal generator 43 output auxiliary signal RM1 and RM2.Since oscillator signal TR1, TR2, PC1, described in detail with the wave character of PC2 and auxiliary signal RM1 and RM2, so locate to omit its explanation at preamble.

Fig. 5 shows the detailed circuit diagram according to first example of many synchronous waveform of leggy oscillator 26 of the present invention.With reference to Fig. 5, oscillator signal generator 41 comprises a peak comparator 411, a valley comparator 412, a latch unit 413, three inverters 414,419S and 419R, a switching device 415, one first current source 416, one second current source 417 and electric capacity 418.The non-oppisite phase end of peak comparator 411 (indicating with symbol "+") is coupled in a peak value setting voltage V _H, the end of oppisite phase of valley comparator 412 (indicating with symbol "-") then is coupled in a valley setting voltage V _LThe end of oppisite phase of peak comparator 411 with the non-oppisite phase end of valley comparator 412 coupled to each other in, and be coupled in output N _TR1The output of peak comparator 411 is coupled in being provided with of latch unit 413 and imports S, and the output of valley comparator 412 then is coupled in the replacement input R of latch unit 413.First current source 416 is connected in direct voltage source V _SourceWith output N _TR1Between, second current source 417 then is connected in output N via switching device 415 _TR1And between the ground.In the embodiment shown in fig. 5, the current value supplied of second current source 417 is the twice of the current value supplied of first current source 416.In the case, the triangular wave that produced of oscillator signal generator 41 is the equilateral triangle ripple that is equal to each other shared time of rising part and shared time of sloping portion.Please note to the invention is not restricted to this, and can be applicable to any situation that satisfies the condition (, subsequently detailed explanation will be arranged) of the current value that current value that second current source 417 supplied supplied greater than first current source 416 about this point.That is, also can produce shared time of rising part and unequal each other non-equilateral triangle ripple of shared time of sloping portion according to oscillator signal generator 41 of the present invention.Switching device 415 is controlled by an output signal of latch unit 413.In the embodiment shown in fig. 5, the normal output Q of latch unit 413 via inverter 414 control switch device 415.Please note because anti-phase output (InvertedOutput) Q of latch unit 413 is the inversion signal of normal output Q, so in another embodiment of the present invention, switching device 415 can be coupled directly to the anti-phase output Q of latch unit 413, can obtain the identical control effect of embodiment shown in Figure 5 equally.In the present invention, switching device 415 can be implemented by a switching transistor, for example nmos pass transistor, PMOS transistor or two-carrier transistor.Electric capacity 418 is connected in output N _TR1And between the ground.

Now describe oscillator signal generator 41 in detail with reference to Fig. 5 and Fig. 2 (b) and how to produce oscillator signal TR1 and oscillator signal PC1 and PC2.As output N _TR1The voltage at place is less than valley setting voltage V _LThe time, it is that the HIGH and the input R that resets are LOW that input S is set, causing normally exporting Q is HIGH.At this moment, inverter 414 output LOW make it not conducting to switching device 415.As a result, second current source 417 is closed obstructed, and 416 pairs of electric capacity of first current source 418 charging, makes output N _TR1The voltage at place rises.As output N _TR1The voltage at place rises to greater than valley setting voltage V _LBut still less than peak value setting voltage V _HThe time, it is that the HIGH and the input R that resets are HIGH that input S is set, causing normally exporting Q is HIGH.At this moment, inverter 414 output LOW make it not conducting to switching device 415.As a result, second current source 417 is still kept and is closed obstructedly, and first current source 416 continues electric capacity 418 chargings, makes output N _TR1The voltage at place continues to rise.As output N _TR1The voltage at place rises to greater than peak value setting voltage V _HThe time, it is that the LOW and the input R that resets are HIGH that input S is set, causing normally exporting Q is LOW.At this moment, inverter 414 output HIGH make it conducting to switching device 415.As a result, second current source, 417 conductings.Because the current value that the current value that second current source 417 is supplied is supplied greater than first current source 416,, make output N so electric capacity 418 is discharged to ground via second current source 417 _TR1The voltage at place descends.As output N _TR1The voltage at place drops to less than peak value setting voltage V _HBut still greater than valley setting voltage V _LThe time, it is that the HIGH and the input R that resets are HIGH that input S is set, causing normally exporting Q is LOW.At this moment, inverter 414 output HIGH make it conducting to switching device 415.As a result, second current source 417 is still kept conducting, makes electric capacity 418 continue to be discharged to ground via second current source 417, causes output N _TR1The voltage at place continues to descend.In the embodiment shown in fig. 5, the current value supplied of second current source 417 is the twice of the current value supplied of first current source 416.In the case, because the discharge current value of electric capacity 418 just equals the current value that first current source 416 is supplied, so the discharge rate of electric capacity 418 equals the charge rate of electric capacity 418 in the previous operational phase in this operational phase, cause the generation of equilateral triangle ripple.As output N _TR1The voltage at place drops to less than valley setting voltage V _LThe time, oscillator signal generator 41 promptly repeats aforesaid operation.Thereby, from output N _TR1The place can obtain desired oscillator signal TR1.

Oscillator signal PC1 makes the input of resetting R is anti-phase by inverter 419R to obtain.Similarly, oscillator signal PC2 makes by inverter 419S input to be set S is anti-phase obtains.

Referring again to Fig. 5, auxiliary signal generator 43 is made up of two ramp generator 43a and 43b, produces auxiliary signal RM1 and RM2 respectively.Ramp generator 43a comprises a sample and hold amplifier 431a, a sampling keeps electric capacity 432a, a voltage-to-current converter 433a, an output capacitance 434a and a switching device 435a.The non-oppisite phase end of sample and hold amplifier 431a is coupled in a reference voltage Vref a, and its output is coupled in the voltage input end of voltage-to-current converter 433a.Sampling keeps electric capacity 432a to be connected between the output and ground of sample and hold amplifier 431a.The current output terminal of voltage-to-current converter 433a is coupled in an output N _RM1Output capacitance 434a and switching device 435a are parallel to output N _RM1And between the ground.Output N _RM1Also be coupled in the end of oppisite phase of sample and hold amplifier 431a, form a feedback loop.On the other hand, ramp generator 43b comprises a sample and hold amplifier 431b, a sampling keeps electric capacity 432b, a voltage-to-current converter 433b, an output capacitance 434b and a switching device 435b.The non-oppisite phase end of sample and hold amplifier 431b is coupled in another reference voltage Vref b, and its output is coupled in the voltage input end of voltage-to-current converter 433b.Sampling keeps electric capacity 432b to be connected between the output and ground of sample and hold amplifier 431b.The current output terminal of voltage-to-current converter 433b is coupled in another output N _RM2Output capacitance 434b and switching device 435b are parallel to output N _RM2And between the ground.Output N _RM2Also be coupled in the end of oppisite phase of sample and hold amplifier 431b, form a feedback loop.

The output of the inverter 419S of oscillator signal generator 41 (that is oscillator signal PC2) is in order to controlled sampling hold amplifier 431a and switching device 435b.On the other hand, the output of the inverter 419R of oscillator signal generator 41 (that is oscillator signal PC1) is in order to controlled sampling hold amplifier 431b and switching device 435a.In the present invention, switching device 435a and 435b must be formed by a switching transistor respectively, for example nmos pass transistor, PMOS transistor or two-carrier transistor.

Now describe auxiliary signal generator 43 in detail with reference to Fig. 5 and Fig. 2 (b) and how to produce auxiliary signal RM1 and RM2.At first explanation is controlled ramp generator 43a to produce the method for auxiliary signal RM1 by oscillator signal PC1 and PC2.When oscillator signal PC1 and PC2 were all LOW, sample and hold amplifier 431a and switching device 435a all closed not conducting.In the case, the fixed voltage that sampling keeps electric capacity 432a to be kept converts fixed current to via voltage-to-current converter 433a, in order to output capacitance 434a is charged.As a result, output N _RM1The voltage at place rises gradually.When oscillator signal PC1 is HIGH and oscillator signal PC2 when being LOW, switching device 435a conducting.In the case, output capacitance 434a is discharged to ground and output N via the switching device 435a of conducting _RM1Be connected in ground via the switching device 435a of conducting.As a result, output N _RM1The voltage instantaneous at place is reduced to earth potential.Thereby, from output N _RM1The place can obtain desired auxiliary signal RM1.The stability of the auxiliary signal RM1 that obtains in order to promote, when oscillator signal PC1 is LOW and oscillator signal PC2 when being HIGH, sample and hold amplifier 431a conducting and via feedback loop output N relatively _RM1The voltage and the reference voltage Vref a at place, thus an error voltage exported, carry out FEEDBACK CONTROL for the voltage that keeps electric capacity 432a to be kept by sampling.Because the voltage that sampling keeps electric capacity 432a to be kept is to convert electric current to via voltage-to-current converter 433a, this electric current decision output N _RM1So the voltage climbing speed at place is from output N _RM1The auxiliary signal RM1 that the place obtains improves stability because of FEEDBACK CONTROL.In the embodiment shown in Fig. 5 and Fig. 2 (b), be the two/one-period place that is positioned at auxiliary signal RM1 since oscillator signal PC2 becomes the time point of HIGH, so reference voltage Vref a can be chosen to be the maximum V of auxiliary signal RM1 _Max1/2nd.Please note to the invention is not restricted to this, and can become the time point of HIGH and feedback voltage that non-oppisite phase end received and the output N of sample and hold amplifier 431a based on oscillator signal PC2 _RM1Proportionate relationship between the voltage at place, selected suitable reference voltage Vref a is to reach desired FEEDBACK CONTROL.

Then explanation is controlled ramp generator 43b to produce the method for auxiliary signal RM2 by oscillator signal PC1 and PC2.When oscillator signal PC1 and PC2 were all LOW, sample and hold amplifier 431b and switching device 435b all closed not conducting.In the case, the fixed voltage that sampling keeps electric capacity 432b to be kept converts fixed current to via voltage-to-current converter 433b, in order to output capacitance 434b is charged.As a result, output N _RM2The voltage at place rises.When oscillator signal PC1 is LOW and oscillator signal PC2 when being HIGH, switching device 435b conducting.In the case, output capacitance 434b is discharged to ground and output N via the switching device 435b of conducting _RM2Be connected in ground via the switching device 435b of conducting.As a result, output N _RM2The voltage instantaneous at place is reduced to earth potential.Thereby, from output N _RM2The place can obtain desired auxiliary signal RM2.The stability of the auxiliary signal RM2 that obtains in order to promote, when oscillator signal PC1 is HIGH and oscillator signal PC2 when being LOW, sample and hold amplifier 431b conducting and via feedback loop output N relatively _RM2The voltage and the reference voltage Vref b at place, thus an error voltage exported, carry out FEEDBACK CONTROL for the voltage that keeps electric capacity 432b to be kept by sampling.Because the voltage system that sampling keeps electric capacity 432b to be kept converts electric current to via voltage-to-current converter 433b, this electric current decision output N _RM2So the voltage climbing speed at place is from output N _RM2The auxiliary signal RM2 that the place obtains improves stability because of FEEDBACK CONTROL.In the embodiment shown in Fig. 5 and 2 (b), be the two/one-period place that is positioned at auxiliary signal RM2 since oscillator signal PC1 becomes the time point of HIGH, so reference voltage Vref b must be chosen to be the maximum V of auxiliary signal RM2 _Max1/2nd.Please note to the invention is not restricted to this, and can become the time point of HIGH and feedback voltage that non-oppisite phase end received and the output N of sample and hold amplifier 431b based on oscillator signal PC1 _RM2Proportionate relationship between the voltage at place, selected suitable reference voltage Vref b is to reach desired FEEDBACK CONTROL.

Fig. 6 shows the detailed circuit diagram according to second example of many synchronous waveform of leggy oscillator 26 of the present invention.Except for the variation of making amendment in order to the circuit that produces oscillator signal PC1 and PC2 and method, second example shown in Figure 6 is same as first example shown in Figure 5.Thereby, be to use similar in appearance to the reference symbol of Fig. 5 similar in appearance to the part of Fig. 5 in the circuit unit shown in Figure 6 to indicate.For the purpose of simplifying the description, hereinafter only describe second example in detail and be different from the first example part.

As shown in Figure 6, second example uses first and second single-shot generator (One ShotGenerator) 611 and 612 to replace the inverter 419R and the 419S of first example shown in Figure 5.Particularly, the first single-shot generator 611 be a rising edge along the single-shot generator, its input is coupled in the normal output Q of latch unit 413.The rising edge that detects normal output Q whenever the first single-shot generator 611 along the time, the first single-shot generator 611 is promptly exported one and is had for example 100 nanoseconds the pulse of predetermined width.Since the rising edge of normally exporting Q is along betiding when oscillator signal TR1 arrives trough, so the first single-shot generator 611 produces desired oscillator signal PC1.On the other hand, the second single-shot generator 612 is a decline edge single-shot generator, and its input is coupled in the normal output Q of latch unit 413.The trailing edge that detects normal output Q whenever the second single-shot generator 612 along the time, the second single-shot generator 612 is promptly exported one and is had for example 100 nanoseconds the pulse of predetermined width.Since the trailing edge of normally exporting Q is along betiding when oscillator signal TR1 arrives crest, so the second single-shot generator 612 produces desired oscillator signal PC2.

Second example shown in Figure 6 provides an extra advantage as described below.Because oscillator signal PC1 and PC2 are by using first and second single-shot generator 611 and 612 generations respectively, so oscillator signal PC1 and PC2 have the pulse of fixed width respectively.As previously mentioned, since oscillator signal PC1 and PC2 be control switch device 435a and 435b respectively, so the pulse of fixed width is guaranteed to fix the discharge time of output capacitance 434a and 434b, thereby the charging interval is also fixed.As a result, the amplitude stability of auxiliary signal RM1 and RM2 is improved more.

In one embodiment of this invention, switch controller 22A to 22D, feedback circuit 24A to 24D, be integrated in the single IC for both chip with many oscillating waveforms of leggy device 26.Change-over circuit 23A to 23D then forms the external circuit of this single IC for both chip, is embodied as decompression converting circuit or voltage up converting circuit, designs according to application demand usually.In another embodiment of the present invention, power switching transistor 25A to 25D among the change-over circuit 23A to 23D also can be integrated in the single IC for both chip with switch controller 22A to 22D, feedback circuit 24A to 24D and many oscillating waveforms of leggy device 26, and the feasible only remainder of change-over circuit 23A to 23D forms the external circuit of this single IC for both chip.

Moreover many synchronous waveform of leggy oscillator 26 also forms an integrated circuit (IC) chip independently separably, is coupled in the integrated circuit (IC) chip that includes power supply service duct 22A to 22D via distribution subsequently.In addition, the also exportable a plurality of oscillator signals of many synchronous waveform of leggy oscillator 26 are given a plurality of integrated circuit (IC) chip with single power supply service duct of individual packages.

Though the present invention is illustrated as illustration by preferred embodiment, the person of should be appreciated that the invention is not restricted to the embodiment that this is described.On the contrary, this invention is intended to contain for those skilled in the art is tangible various modification and equivalent arrangements.Therefore, protection scope of the present invention should be according to the widest annotation, to contain all this type of modification and equivalent arrangements.

Claims (19)

1. suitching type DC-DC converter comprises:

One first power supply service duct is coupled between a direct current voltage source and the ground, becomes one first VD in order to change this direct voltage source;

One second source service duct is coupled between this direct voltage source and the ground, becomes one second VD in order to change this direct voltage source, and this second VD and this first VD are separated; And

One oscillator, one first oscillator signal that has a period 1 in order to output be to this first power supply service duct, and one second oscillator signal that has a second round in order to output is to this second source service duct, wherein:

In each cycle of this period 1, this first oscillator signal has a crest, a trough, increases to a rising part of this crest gradually and be gradually reduced to a decline part of this trough from this crest from this trough, makes the switching transition of this first power supply service duct betide in this rising part and one of them time range that is contained of this sloping portion of this first oscillator signal;

In each cycle of this second round, this second oscillator signal has the edge of transition in a flash, one of them takes place this crest of the edge of these moment transition and this first oscillator signal and this trough simultaneously, makes the switching transition of this second source service duct and the edge of these moment transition take place simultaneously.

2. suitching type DC-DC converter according to claim 1, wherein:

This oscillator comprises:

One valley comparator is in order to relatively this first oscillator signal and a valley setting voltage; And

One inverter, its input are coupled in an output of this valley comparator, in order to produce this second oscillator signal.

3. suitching type DC-DC converter according to claim 1, wherein:

This oscillator comprises:

One peak comparator is in order to relatively this first oscillator signal and a peak value setting voltage;

One valley comparator is in order to relatively this first oscillator signal and a valley setting voltage;

One latch unit, it is provided with the output that input is coupled in this peak comparator, and its replacement input is coupled in an output of this valley comparator, in order to produce a normally output; And

One rising edge is along the single-shot generator, in order to produce this second oscillator signal in response to this normal output.

4. suitching type DC-DC converter according to claim 1, wherein:

This oscillator is also exported one first auxiliary signal to this second source service duct, wherein this first auxiliary signal is an oblique wave oscillator signal, have a rising part and a decline edge, make this trailing edge edge and the edge of these moment transition of this second oscillator signal take place simultaneously.

5. suitching type DC-DC converter according to claim 4, wherein:

This oscillator comprises:

One peak comparator is in order to relatively this first oscillator signal and a peak value setting voltage;

One valley comparator is in order to relatively this first oscillator signal and a valley setting voltage;

One first inverter, its input are coupled in an output of this valley comparator, in order to produce this second oscillator signal;

One second inverter, its input are coupled in an output of this peak comparator;

One auxiliary output is in order to export this first auxiliary signal;

One sample and hold amplifier is controlled by this second inverter, in order to relatively this first auxiliary signal and a reference voltage;

One sampling keeps electric capacity, is coupled between the output and ground of this sample and hold amplifier;

One voltage-to-current converter, its voltage input end are coupled in this output of this sample and hold amplifier, and its current output terminal is coupled in this auxiliary output;

One output capacitance is coupled between this auxiliary output and the ground;

And

One switching device shifter is coupled between this auxiliary output and the ground, is controlled by this first inverter.

6. suitching type DC-DC converter according to claim 4, wherein:

This oscillator comprises:

One peak comparator is in order to relatively this first oscillator signal and a peak value setting voltage;

One valley comparator is in order to relatively this first oscillator signal and a valley setting voltage;

One latch unit, it is provided with the output that input is coupled in this peak comparator, and its replacement input is coupled in an output of this valley comparator, in order to produce a normally output;

One rising edge is along the single-shot generator, in order to produce this second oscillator signal in response to this normal output;

One decline edge single-shot generator should normally be exported in order to receive;

One auxiliary output is in order to export this first auxiliary signal;

One sample and hold amplifier is controlled along the single-shot generator by this trailing edge, in order to relatively this first auxiliary signal and a reference voltage;

One sampling keeps electric capacity, is coupled between the output and ground of this sample and hold amplifier;

One voltage-to-current converter, its voltage input end are coupled in this output of this sample and hold amplifier, and its current output terminal is coupled in this auxiliary output;

One output capacitance is coupled between this auxiliary output and the ground; And

One switching device shifter is coupled between this auxiliary output and the ground, is controlled along the single-shot generator by this rising edge.

7. suitching type DC-DC converter according to claim 1 also comprises:

One the 3rd power supply service duct is coupled between this direct voltage source and this ground, becomes one the 3rd VD in order to change this direct voltage source, and the 3rd VD and this first is separated with this second VD, wherein:

This oscillator also export have a period 3 one the 3rd oscillator signal to the 3rd power supply service duct;

In each cycle of this period 3, the 3rd oscillator signal has a crest, a trough, increases to a rising part of this crest and a decline part that is gradually reduced to this trough from this crest gradually from this trough, make this crest of the 3rd oscillator signal and this trough of this first oscillator signal take place simultaneously, and this crest of this trough of the 3rd oscillator signal and this first oscillator signal take place simultaneously; And

At least one switching transition of the 3rd power supply service duct betide in this rising part and one of them time range that is contained of this sloping portion of the 3rd oscillator signal.

8. suitching type DC-DC converter according to claim 1 also comprises:

One the 4th power supply service duct is coupled between this direct voltage source and this ground, becomes one the 4th VD in order to change this direct voltage source, and the 4th VD and this first is separated with this second VD, wherein:

This oscillator also export have a period 4 one the 4th oscillator signal to the 4th power supply service duct;

In each cycle of this period 4, the 4th oscillator signal has the edge of transition in a flash, and one of them takes place edge that wherein should the moment transition and this crest of this first oscillator signal and this trough simultaneously;

Have preset time skew between the edge of the edge of these moment transition of the 4th oscillator signal and these moment transition of this second oscillator signal; And

The edge of at least one switching transition of the 4th power supply service duct and these moment transition of the 4th oscillator signal takes place simultaneously.

9. suitching type DC-DC converter according to claim 8, wherein:

This oscillator is also exported one second auxiliary signal to the 4th power supply service duct, wherein this second auxiliary signal is an oblique wave oscillator signal, have a rising part and a decline edge, make this trailing edge edge and the edge of these moment transition of the 4th oscillator signal take place simultaneously.

10. suitching type DC-DC converter according to claim 9, wherein:

This oscillator comprises:

One auxiliary output is in order to export this second auxiliary signal;

One sample and hold amplifier is controlled by this second oscillator signal, in order to relatively this second auxiliary signal and a reference voltage;

One sampling keeps electric capacity, is coupled between the output and ground of this sample and hold amplifier;

One voltage-to-current converter, its voltage input end are coupled in this output of this sample and hold amplifier, and its current output terminal is coupled in this auxiliary output;

One output capacitance is coupled between this auxiliary output and the ground;

And

One switching device shifter is coupled between this auxiliary output and the ground, is controlled by the 4th oscillator signal.

11. an oscillator comprises:

One installs, and has one first oscillator signal of a period 1 in order to output; And

One device, one second oscillator signal that has a second round in order to output, wherein:

In each cycle of this period 1, this first oscillator signal has a crest, a trough, increases to a rising part of this crest and a decline part that is gradually reduced to this trough from this crest gradually from this trough; And

In each cycle of this second round, this second oscillator signal has the edge of transition in a flash, and one of them takes place edge that wherein should the moment transition and this crest of this first oscillator signal and this trough simultaneously.

12. oscillator according to claim 11, wherein:

This first oscillator signal is a triangular wave oscillation signal.

13. oscillator according to claim 11, wherein:

This second oscillator signal is an impulse oscillation signal, in each cycle of this second round, have rising edge edge, a pulse duration, with a decline edge, and the edge of these moment transition of this second oscillator signal is meant its this rising edge edge.

14. oscillator according to claim 11 also comprises:

One device, in order to export one first auxiliary signal, wherein this first auxiliary signal is an oblique wave oscillator signal, has a rising part and a decline edge, makes this trailing edge edge and the edge of these moment transition of this second oscillator signal take place simultaneously.

15. oscillator according to claim 11 also comprises:

One device has one the 3rd oscillator signal of a period 3 in order to output, wherein:

In each cycle of this period 3, the 3rd oscillator signal has a crest, a trough, increases to a rising part of this crest and a decline part that is gradually reduced to this trough from this crest gradually from this trough, make this crest of the 3rd oscillator signal and this trough of this first oscillator signal take place simultaneously, and this crest of this trough of the 3rd oscillator signal and this first oscillator signal take place simultaneously.

16. oscillator according to claim 15, wherein:

The 3rd oscillator signal is the inversion signal of this first oscillator signal.

17. oscillator according to claim 11 also comprises:

One device has one the 4th oscillator signal of a period 4 in order to output, wherein:

In each cycle of this period 4, the 4th oscillator signal has the edge of transition in a flash, and one of them takes place edge that wherein should the moment transition and this crest of this first oscillator signal and this trough simultaneously, and

Have preset time skew between the edge of the edge of these moment transition of the 4th oscillator signal and these moment transition of this second oscillator signal.

18. oscillator according to claim 17, wherein:

The 4th oscillator signal is an impulse oscillation signal, in each cycle of this period 4, have rising edge edge, a pulse duration, with a decline edge, and the edge of these moment transition of the 4th oscillator signal is meant its this rising edge edge.

19. oscillator according to claim 17 also comprises:

One device, in order to export one second auxiliary signal, wherein this second auxiliary signal is an oblique wave oscillator signal, has a rising part and a decline edge, makes this trailing edge edge and the edge of these moment transition of the 4th oscillator signal take place simultaneously.

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