CN203813661U - Primary control flyback switch power supply control chip and output line voltage compensating circuit - Google Patents

Primary control flyback switch power supply control chip and output line voltage compensating circuit Download PDF

Info

Publication number
CN203813661U
CN203813661U CN201420117412.9U CN201420117412U CN203813661U CN 203813661 U CN203813661 U CN 203813661U CN 201420117412 U CN201420117412 U CN 201420117412U CN 203813661 U CN203813661 U CN 203813661U
Authority
CN
China
Prior art keywords
input
output
termination
circuit
voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN201420117412.9U
Other languages
Chinese (zh)
Inventor
周健
宗强
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Fei Kepu Electronic Science And Technology Co Ltd
Original Assignee
Shanghai Fei Kepu Electronic Science And Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Fei Kepu Electronic Science And Technology Co Ltd filed Critical Shanghai Fei Kepu Electronic Science And Technology Co Ltd
Priority to CN201420117412.9U priority Critical patent/CN203813661U/en
Application granted granted Critical
Publication of CN203813661U publication Critical patent/CN203813661U/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The utility model discloses a primary control flyback switch power supply control chip. The primary control flyback switch power supply control chip comprises a constant voltage control circuit, a demagnetization detection circuit, an output line voltage compensating circuit, a peak value current comparator and a switch signal generation circuit, the demagnetization detection circuit obtains demagnetization signals by the detection of output feedback voltage of a primary control flyback switch power supply, and the output line voltage compensating circuit outputs a pull-down current and a pull-down output feedback voltage by the detection of the duty ratio of the demagnetization signals. The higher of the output current of the primary control flyback switch power supply, the higher of the duty ratio of the demagnetization signals, and the higher of the pull-down current so that the output voltage of the primary control flyback switch power supply is higher. According to the primary control flyback switch power supply control chip, output line voltage compensation can be realized without external capacitors, the cost of the primary control flyback switch power supply is lowered, and the reliability is improved. The utility model also discloses an output line voltage compensating circuit.

Description

Inverse-excitation type switch power-supply control chip and output line voltage compensating circuit are controlled in former limit
Technical field
The utility model relates to switch power technology, and particularly inverse-excitation type switch power-supply control chip and output line voltage compensating circuit are controlled in former limit.
Background technology
With respect to conventional linear power supply, to have volume little because of it for Switching Power Supply, good stability, and the high and low characteristic of cost of conversion efficiency has been a requisite technology in microprocessor and other electronic products.
In various types of Switching Power Supplies, inverse-excitation type switch power-supply is the most common.One of core parts of inverse-excitation type switch power-supply are transformers, and it provides the electrical isolation of input and output.Conventionally this transformer has former limit winding and secondary winding, and one or more auxiliary winding.Inverse-excitation type switch power-supply is generally used in low cost, lower powered occasion.
The inverse-excitation type switch power-supply of controlling with respect to secondary, the inverse-excitation type switch power-supply that former limit is controlled is by when former limit switching tube turn-offs, utilize an auxiliary winding of transformer to reflect that the voltage of secondary winding realizes the object of controlling power output, saved the cost of photoelectrical coupler.
In the face of current increasing cellular li-ion battery electric weight on the market, large charging current becomes a kind of trend.The inverse-excitation type switch power-supply that former limit is controlled can provide at the port of printed circuit version accurate output voltage, but at the interface that really accesses mobile phone terminal, but because large electric current is flowed through, the reason generation voltage of output line falls, output current is larger, output line equivalent resistance is larger, and falling of voltage is also just larger.
The method that is generally used on the market at present output line voltage compensation is an external building-out capacitor, and this electric capacity, by filtered switch signal, obtains the information of output line electric current, then according to gained current information, carries out output line voltage compensation.But this technology, because introduce the reason of external building-out capacitor, has caused the rising of cost and the decline of reliability.
Fig. 1 is that inverse-excitation type switch power-supply structure is controlled on traditional former limit with output line voltage compensation, and it comprises three-winding transformer 20a, control chip 10a; Three-winding transformer 20a comprises former limit winding 201a, auxiliary winding 202a, secondary winding 203a; Auxiliary winding 202a powers to control chip 10a and provides former limit to control the measuring ability of the output voltage of inverse-excitation type switch power-supply; Control chip 10a carrys out the turn-on and turn-off of control switch pipe Q by output switching signal Vd, thereby realizes the function of the output voltage modulation of controlling inverse-excitation type switch power-supply in former limit.
Inverse-excitation type switch power-supply is controlled on traditional former limit with output line voltage compensation, and the demagnetization testing circuit 102a of control chip 10a exports the feedback voltage Vfb signal Demag that obtains demagnetizing by detection; Described demagnetization signal Demag is high while controlling the secondary rectifier diode D2 conducting of inverse-excitation type switch power-supply on former limit, is low during shutoff; The output current detection circuit 103a of control chip 10a and external capacitor C L control voltage Vc by the filtering of demagnetization signal Demag is obtained to constant voltage, and the output current that inverse-excitation type switch power-supply is controlled on former limit is larger, and it is higher that constant voltage is controlled voltage Vc; Constant voltage is controlled voltage Vc and is added and obtains constant voltage reference voltage Vref2 with chip internal reference voltage V ref1 according to a certain percentage; The output voltage of constant-voltage control circuit 101a is controlled at constant voltage reference voltage Vref2 constantly in the demagnetization of output feedback voltage Vfb, thereby realizes the function of output line voltage compensation.When in former limit winding 201a, electric current is greater than the reference current Iref of peak current comparator 106a positive input terminal access, control chip 10a control switch pipe Q turn-offs.
The control chip 10a of inverse-excitation type switch power-supply is controlled on above-mentioned traditional former limit with output line voltage compensation, need the demagnetize filtering of signal Demag of external capacitor C L, and the ratio of output line voltage compensation is fixed.
Utility model content
The technical problems to be solved in the utility model is to provide a kind of former limit and controls inverse-excitation type switch power-supply control chip, does not need external electric capacity, and output line voltage compensating proportion capable of regulating in the situation that former limit control inverse-excitation type switch power-supply does not increase external devices.
For solving the problems of the technologies described above, inverse-excitation type switch power-supply control chip is controlled on the former limit that the utility model provides, and it comprises that constant-voltage control circuit, demagnetization testing circuit, output line voltage compensating circuit, peak current comparator, switching signal produce circuit, drive circuit, feedback voltage input, detect current input terminal, switching signal output;
Described constant-voltage control circuit, feedback voltage input described in input termination, switching signal produces the Continuity signal input of circuit described in output termination; Described constant-voltage control circuit, when the voltage of input is while being greater than setting voltage, exports a pulse through a delay time, and the described delay time is directly proportional to the voltage of input;
Described peak current comparator, the detection current input terminal of negative input termination control chip, positive input termination reference current, switching signal produces the cut-off signals input of circuit described in output termination;
Described demagnetization testing circuit, the feedback voltage input of input termination control chip, the input of output line voltage compensating circuit described in output termination; Described demagnetization testing circuit, for exporting demagnetization signal, when the voltage of input is greater than setting voltage, the demagnetization signal of output is high level, when the voltage of input is less than or equal to setting voltage, the demagnetization signal of output is low level;
Described output line voltage compensating circuit, the feedback voltage input of output termination control chip; Described output line voltage compensating circuit, for demagnetization signal is carried out to filtering, and output to after filtering after the pull-down current that is directly proportional of demagnetization signal;
Described switching signal produces circuit, drive circuit input described in output termination; Described switching signal produces circuit, when cut-off signals input level is jumped to when high by low, starts to export high level; When Continuity signal input level is jumped to when high by low, start output low level;
Described drive circuit, the switching signal output of output termination control chip; Described drive circuit, for output after input signal is amplified.
Preferably, described output line voltage compensating circuit, comprises that a prefilter, a switching capacity filter and a voltage turn current circuit;
Described prefilter, the input of output line voltage compensating circuit described in input termination, the first input end of switching capacity filter described in output termination;
Described switching capacity filter, the input of output line voltage compensating circuit described in the second input termination, voltage turns the input of current circuit described in output termination;
Described voltage turns current circuit, the output of output line voltage compensating circuit described in output termination.
Preferably, described prefilter, comprises the 4th resistance, the 4th electric capacity;
Described the 4th resistance, the input of prefilter described in a termination, the output of prefilter described in another termination;
Described the 4th electric capacity, the output of prefilter described in a termination, other end ground connection.
Preferably, described switching capacity filter, comprises inverter, the 5th electric capacity, the 6th electric capacity, the first control switch, the second control switch;
Conducting when the first control switch, the second control switch are high at control end current potential, turn-offs when low;
Described inverter, the second input of switching capacity filter and the control end of described the first control switch described in input termination, the control end of the second control switch described in output termination;
Described the first control switch, the first input end of switching capacity filter described in a conduction current termination, one end of the 5th electric capacity and a conduction current end of described the second control switch described in another conduction current termination;
The 6th one end of electric capacity and the output of described switching capacity filter described in another conduction current termination of described the second control switch;
The other end ground connection of the other end of described the 5th electric capacity and described the 6th electric capacity.
Preferably, described voltage turns current circuit, comprises operational amplifier, the 5th resistance, a PMOS pipe, the 2nd PMOS pipe, the 3rd NMOS pipe, the 4th NMOS pipe, the 5th NMOS pipe;
Described operational amplifier, voltage turns the input of current circuit described in positive input termination, the source electrode of the 3rd NMOS pipe described in negative input termination, the grid of the 3rd NMOS pipe described in output termination;
Described the 3rd NMOS pipe, drain electrode connects the drain electrode of a described PMOS pipe and the grid of grid and described the 2nd PMOS pipe;
The source electrode of a described PMOS pipe and described the 2nd PMOS pipe joins;
Described the 2nd PMOS pipe, drain electrode connects the drain electrode of described the 4th NMOS pipe and the grid of grid and described the 5th NMOS pipe;
The source ground of described the 4th NMOS pipe and described the 5th NMOS pipe;
Described the 5th NMOS pipe, drain electrode connects the output that described voltage turns current circuit;
Described the 5th resistance, the negative input end of operational amplifier described in a termination, other end ground connection.
The invention also discloses a kind of output line voltage compensating circuit, comprise that a prefilter, a switching capacity filter and a voltage turn current circuit;
Described prefilter, the input of output line voltage compensating circuit described in input termination, the first input end of switching capacity filter described in output termination;
Described switching capacity filter, the input of output line voltage compensating circuit described in the second input termination, voltage turns the input of current circuit described in output termination;
Described voltage turns current circuit, the output of output line voltage compensating circuit described in output termination.
Preferably, described prefilter, comprises the 4th resistance, the 4th electric capacity;
Described the 4th resistance, the input of prefilter described in a termination, the output of prefilter described in another termination;
Described the 4th electric capacity, the output of prefilter described in a termination, other end ground connection;
Described prefilter, time constant is arranged on hundred microsecond ranks.
Preferably, described switching capacity filter, comprises inverter, the 5th electric capacity, the 6th electric capacity, the first control switch, the second control switch;
Conducting when the first control switch, the second control switch are high at control end current potential, turn-offs when control end current potential is low;
Described inverter, the second input of switching capacity filter and the control end of described the first control switch described in input termination, the control end of the second control switch described in output termination;
Described the first control switch, the first input end of switching capacity filter described in a conduction current termination, one end of the 5th electric capacity and a conduction current end of described the second control switch described in another conduction current termination;
The 6th one end of electric capacity and the output of described switching capacity filter described in another conduction current termination of described the second control switch;
The other end ground connection of the other end of described the 5th electric capacity and described the 6th electric capacity.
Preferably, described voltage turns current circuit, comprises operational amplifier, the 5th resistance, a PMOS pipe, the 2nd PMOS pipe, the 3rd NMOS pipe, the 4th NMOS pipe, the 5th NMOS pipe;
Described operational amplifier, voltage turns the input of current circuit described in positive input termination, the source electrode of the 3rd NMOS pipe described in negative input termination, the grid of the 3rd NMOS pipe described in output termination;
Described the 3rd NMOS pipe, drain electrode connects the drain electrode of a described PMOS pipe and the grid of grid and described the 2nd PMOS pipe;
The source electrode of a described PMOS pipe and described the 2nd PMOS pipe joins;
Described the 2nd PMOS pipe, drain electrode connects the drain electrode of described the 4th NMOS pipe and the grid of grid and described the 5th NMOS pipe;
The source ground of described the 4th NMOS pipe and described the 5th NMOS pipe;
Described the 5th NMOS pipe, drain electrode connects the output that described voltage turns current circuit;
Described the 5th resistance, the negative input end of operational amplifier described in a termination, other end ground connection.
Inverse-excitation type switch power-supply control chip is controlled on former limit of the present utility model, demagnetization testing circuit is controlled the output feedback voltage of inverse-excitation type switch power-supply by detecting former limit, obtain the signal that demagnetizes, output line voltage compensating circuit is recently exported pull-down current by the demagnetize duty of signal of detection, drop-down output feedback voltage, the output current that inverse-excitation type switch power-supply is controlled on former limit is larger, the duty ratio of demagnetization signal is also just larger, pull-down current is larger, higher thereby the output voltage of reverse exciting switching voltage regulator is controlled on former limit.Inverse-excitation type switch power-supply control chip is controlled on former limit of the present utility model, do not need external electric capacity can realize former limit and control the compensation of inverse-excitation type switch power-supply output line voltage, can reduce former limit and control the cost of inverse-excitation type switch power-supply and improve the reliability that inverse-excitation type switch power-supply is controlled on former limit; And change former limit and control the ratio that value of the original feedback resistance of inverse-excitation type switch power-supply can adjust output line voltage compensation, thereby not increasing former limit control inverse-excitation type switch power-supply external devices is its output line voltage compensating proportion of capable of regulating, can improve the range of application that inverse-excitation type switch power-supply is controlled on former limit, for user provides larger facility.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical solution of the utility model, below the accompanying drawing of the required use of the utility model is briefly described, apparently, accompanying drawing in the following describes is only embodiment more of the present utility model, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is that inverse-excitation type switch power-supply structural representation is controlled on traditional former limit with output line voltage compensation;
Fig. 2 is that inverse-excitation type switch power-supply control chip one example structure schematic diagram is controlled on former limit of the present utility model;
Fig. 3 is the output line voltage compensating circuit structural representation that inverse-excitation type switch power-supply control chip one embodiment is controlled on former limit of the present utility model;
Fig. 4 is the switching capacity filter structural representation that the output line voltage compensating circuit of inverse-excitation type switch power-supply control chip one embodiment is controlled on former limit of the present utility model;
Fig. 5 is the work wave to each key node of former limit control inverse-excitation type switch power-supply output line voltage compensation that adopts control chip of the present utility model.
Embodiment
Below in conjunction with accompanying drawing, the technical scheme in the utility model is carried out to clear, complete description, obviously, described embodiment is a part of embodiment of the present utility model, rather than whole embodiment.Embodiment based in the utility model, all other embodiment that those of ordinary skills obtain under the prerequisite of not making creative work, belong to the scope that the utility model is protected.
Embodiment mono-
Inverse-excitation type switch power-supply control chip is controlled on former limit, as shown in Figure 2, control chip 10 comprises that constant-voltage control circuit 101, demagnetization testing circuit 102, output line voltage compensating circuit 103, peak current comparator 106, switching signal produce circuit 104, drive circuit 105, feedback voltage input, detect current input terminal, switching signal output;
Described constant-voltage control circuit 101, feedback voltage input described in input termination, switching signal produces the Continuity signal input of circuit 104 described in output termination; Described constant-voltage control circuit 101, when the voltage of input is while being greater than setting voltage, exports a pulse through a delay time, and the described delay time is directly proportional to the voltage of input;
Described peak current comparator 106, the detection current input terminal of negative input termination control chip 10, positive input termination reference current Iref, switching signal produces the cut-off signals input of circuit 104 described in output termination;
Described demagnetization testing circuit 102, the feedback voltage input of input termination control chip 10, the input of output line voltage compensating circuit 103 described in output termination; Described demagnetization testing circuit 102, be used for exporting demagnetization signal Demag, when the voltage of input is greater than setting voltage, the demagnetization signal Demag of output is high level, when the voltage of input is less than or equal to setting voltage, the demagnetization signal Demag of output is low level;
Described output line voltage compensating circuit 103, the feedback voltage input of output termination control chip 10; Described output line voltage compensating circuit 103, for demagnetization signal Demag is carried out to filtering, and output to after filtering after the pull-down current Ifb that is directly proportional of demagnetization signal;
Described switching signal produces circuit 104, drive circuit 105 inputs described in output termination; Described switching signal produces circuit 104, when cut-off signals input level is jumped to when high by low, starts to export high level; When Continuity signal input level is jumped to when high by low, start output low level;
Described drive circuit 105, the switching signal output of output termination control chip 10; Described drive circuit, for output after input signal is amplified.
As shown in Figure 2, the three-winding transformer 20 in inverse-excitation type switch power-supply is controlled on former limit, comprises former limit winding 201, auxiliary winding 202, secondary winding 203; Auxiliary winding 202 is powered to control chip 10 and is provided former limit to control the measuring ability of the output voltage of inverse-excitation type switch power-supply; Control chip 10 carrys out the turn-on and turn-off of control switch pipe Q by output switching signal Vd, thereby realize the function of the output voltage modulation of controlling inverse-excitation type switch power-supply in former limit, when winding 201 interior electric currents in former limit are greater than the reference current Iref of peak current comparator 106 positive input terminal accesses, control chip 10 control switch pipe Q turn-off.
Suppose that the maximum pull-down current under control chip 10 full load conditions is Ifbmax, full-load voltage is Ifbmax*R1*Ns/Na with respect to floating voltage in the amplitude of former limit control inverse-excitation type switch power-supply printed circuit board end lifting, wherein Na is the number of turn that the auxiliary winding 202 of the three-winding transformer 20 in reverse exciting switching voltage regulator is controlled on former limit, Ns is the number of turn of the secondary winding 203 of three-winding transformer 20, and R1 is the feedback resistance that inverse-excitation type switch power-supply is controlled on former limit.
Inverse-excitation type switch power-supply control chip is controlled on the former limit of embodiment mono-, demagnetization testing circuit 102 is controlled the output feedback voltage Vfb of inverse-excitation type switch power-supply by detecting former limit, signal Demag obtains demagnetizing, output line voltage compensating circuit 103 is recently exported pull-down current Ifb by the demagnetize duty of signal Demag of detection, drop-down output feedback voltage Vfb, the output current that inverse-excitation type switch power-supply is controlled on former limit is larger, the duty ratio of demagnetization signal Demag is also just larger, pull-down current Ifb is larger, higher thereby the output voltage of reverse exciting switching voltage regulator is controlled on former limit.Inverse-excitation type switch power-supply control chip is controlled on the former limit of embodiment mono-, do not need external electric capacity can realize former limit and control the compensation of inverse-excitation type switch power-supply output line voltage, can reduce former limit and control the cost of inverse-excitation type switch power-supply and improve the reliability that inverse-excitation type switch power-supply is controlled on former limit; And change former limit and control the ratio that value of the original feedback resistance R1 of inverse-excitation type switch power-supply can adjust output line voltage compensation, thereby not increasing former limit control inverse-excitation type switch power-supply external devices is its output line voltage compensating proportion of capable of regulating, can improve the range of application that inverse-excitation type switch power-supply is controlled on former limit, for user provides larger facility.
Embodiment bis-
Inverse-excitation type switch power-supply control chip is controlled on former limit based on embodiment mono-, and as shown in Figure 3, described output line voltage compensating circuit 103, comprises that a prefilter, a switching capacity filter and a voltage turn current module;
Described prefilter, the input of output line voltage compensating circuit 103 described in input termination, the first input end of switching capacity filter described in output termination;
Described switching capacity filter, the input of output line voltage compensating circuit described in the second input termination, voltage turns the input of current circuit described in output termination;
Described voltage turns current circuit, and output is as the output of described output line voltage compensating circuit 103.
Preferably, described prefilter, comprises the 4th resistance R 4, the 4th capacitor C 4;
The input of prefilter described in described the 4th resistance R 4, one terminations, the output of prefilter described in another termination;
The output of prefilter described in described the 4th capacitor C 4, one terminations, other end ground connection;
Described prefilter, time constant is preferably arranged on hundred microsecond ranks.
Preferably, described switching capacity filter, as shown in Figure 4, comprises inverter, the 5th capacitor C 5, the 6th capacitor C 6, the first control switch S1, the second control switch S2;
Conducting when the first control switch S1, the second control switch S2 are high at control end current potential, turn-offs when low;
Described inverter, the second input of switching capacity filter and the control end of described the first control switch S1 described in input termination, the control end of the second control switch S2 described in output termination;
Described the first control switch S1, a conduction current terminates at the first input end of described switching capacity filter, one end of the 5th capacitor C 5 and a conduction current end of described the second control switch S2 described in another conduction current termination;
The 6th one end of capacitor C 6 and the output of described switching capacity filter described in another conduction current termination of described the second control switch S2;
The other end ground connection of the other end of described the 5th capacitor C 5 and described the 6th capacitor C 6.
The time constant filter of switching capacity filter is C6/ (C5*FDemag), and wherein FDemag is the operating frequency of demagnetization signal Demag.The switching frequency of system is lower, and the operating frequency of demagnetization signal Demag is lower, and the time constant filter of switching capacity filter is larger, and switching system is more stable.Operated by rotary motion the 5th capacitor C 5 is that 20 times of the 6th capacitor C 6 are above to realize the stability of switching system.
Preferably, described voltage turns current circuit, comprises operational amplifier, the 5th resistance R 5, a PMOS pipe M1, the 2nd PMOS pipe M2, the 3rd NMOS pipe M3, the 4th NMOS pipe M4, the 5th NMOS pipe M5;
Described operational amplifier, voltage turns the input of current circuit described in positive input termination, the source electrode of the 3rd NMOS pipe M3 described in negative input termination, the grid of the 3rd NMOS pipe M3 described in output termination;
Described the 3rd NMOS pipe M3, drain electrode connects the drain electrode of a described PMOS pipe M1 and the grid of grid and described the 2nd PMOS pipe M2;
The source electrode of a described PMOS pipe M1 and described the 2nd PMOS pipe M2 joins;
Described the 2nd PMOS pipe M2, drain electrode connects the drain electrode of described the 4th NMOS pipe M4 and the grid of grid and described the 5th NMOS pipe M5;
The source ground of described the 4th NMOS pipe M4 and described the 5th NMOS pipe M5;
Described the 5th NMOS pipe M5, drain electrode connects the output that described voltage turns current circuit;
The negative input end of operational amplifier described in described the 5th resistance R 5, one terminations, other end ground connection.
Inverse-excitation type switch power-supply control chip is controlled on the former limit of embodiment bis-, the switch control end of the switching capacity filter 303 in output line voltage compensating circuit 103 is demagnetization signal Demag, by the filter action of switching capacity filter, the direct current signal Vo of output reflection output current, output current is larger, and the direct current signal Vo of switching capacity filter output is higher.Voltage turns current circuit, exports pull-down current Ifb, Ifb=K*Vo/R5, and K is the image ratio of the current mirror of a PMOS pipe M1, the 2nd PMOS pipe M2, the 4th NMOS pipe M4, the 5th NMOS pipe M5 composition.The direct current signal Vo of switching capacity filter output is higher, and the pull-down current Ifb that voltage turns current circuit output is also just larger, thereby realizes the object of output line voltage compensation.
The switching power source control circuit of embodiment bis-, to the waveform of the key point of the output line voltage compensation of former limit control reverse exciting switching voltage regulator as shown in Figure 5.When the switching signal Vd of switching power source control circuit output is high potential, the main power tube Q conducting of reverse exciting switching voltage regulator is controlled on former limit, linear the increasing of electric current in the former limit winding 201 of three-winding transformer 20, when electric current is increased to reference current Iref, main power tube Q turn-offs, and the ON time of main power tube Q is tonp.After main power tube Q turn-offs, secondary winding 203 starts afterflow, sustained diode 2 conductings, output feedback voltage Vfb raises, and demagnetization signal Demag becomes high level, the output signal Vi of described prefilter starts to rise, described the first control switch S1 conducting, described the second control switch S2 turn-offs, and the voltage of described the 5th capacitor C 5 equals the output signal Vi of described prefilter, the direct current signal Vo of the output of switching capacity filter is constant, and time of afterflow is designated as Tons.When secondary coil 203 afterflows finish, sustained diode 2 is turn-offed, output feedback voltage Vfb reduces, demagnetization signal Demag becomes low level, the output signal Vi of described prefilter starts to decline, and described the first control switch S1 leads shutoff, described the second control switch S2 conducting, the 5th capacitor C 5 equates with the voltage of the 6th capacitor C 6, thereby realizes the effect of switching capacity.Because whole former limit is controlled inverse-excitation type switch power-supply and is operated in constant peak current-mode, the value that inverse-excitation type switch power-supply output current Iout is controlled on former limit is: Iout=Iref*Ns*Tons/[(Tons+Tonp+Toff) * Np], Toff is the difference that the delay time of described constant-voltage control circuit 101 output one pulses deducts time of afterflow Tons; When former limit control inverse-excitation type switch power-supply output current Iout becomes large, time of afterflow Tons ratio in whole switch periods becomes large, the rise time of the output signal Vi of described prefilter proportion in whole switch periods raises, it is large that the D. C. value of the direct current signal Vo of the output of switching capacity filter becomes, the pull-down current Ifb that voltage turns current circuit output increases, thereby realizes the object of switching power source control circuit output line voltage compensation.
Inverse-excitation type switch power-supply control chip is controlled on the former limit of embodiment bis-, by the switching capacity filter in its output line voltage compensating circuit 103, realize the filtering to demagnetization signal Demag, obtain the low frequency signal of output current, then by the output voltage height in this Signal Regulation different output current situation, thereby control chip, without external filter capacitor, is controlled the proportional current signal of inverse-excitation type switch power-supply output current to former limit for exportable one.
The foregoing is only preferred embodiment of the present utility model; not in order to limit the utility model; all within spirit of the present utility model and principle, any modification of making, be equal to replacement, improvement etc., within all should being included in the scope of the utility model protection.

Claims (9)

1. inverse-excitation type switch power-supply control chip is controlled on a former limit, it is characterized in that, control chip comprises that constant-voltage control circuit, demagnetization testing circuit, output line voltage compensating circuit, peak current comparator, switching signal produce circuit, drive circuit, feedback voltage input, detect current input terminal, switching signal output;
Described constant-voltage control circuit, feedback voltage input described in input termination, switching signal produces the Continuity signal input of circuit described in output termination; Described constant-voltage control circuit, when the voltage of input is while being greater than setting voltage, exports a pulse through a delay time, and the described delay time is directly proportional to the voltage of input;
Described peak current comparator, the detection current input terminal of negative input termination control chip, positive input termination reference current, switching signal produces the cut-off signals input of circuit described in output termination;
Described demagnetization testing circuit, the feedback voltage input of input termination control chip, the input of output line voltage compensating circuit described in output termination; Described demagnetization testing circuit, for exporting demagnetization signal, when the voltage of input is greater than setting voltage, the demagnetization signal of output is high level, when the voltage of input is less than or equal to setting voltage, the demagnetization signal of output is low level;
Described output line voltage compensating circuit, the feedback voltage input of output termination control chip; Described output line voltage compensating circuit, for demagnetization signal is carried out to filtering, and output to after filtering after the pull-down current that is directly proportional of demagnetization signal;
Described switching signal produces circuit, drive circuit input described in output termination; Described switching signal produces circuit, when cut-off signals input level is jumped to when high by low, starts to export high level; When Continuity signal input level is jumped to when high by low, start output low level;
Described drive circuit, the switching signal output of output termination control chip; Described drive circuit, for output after input signal is amplified.
2. inverse-excitation type switch power-supply control chip is controlled on former limit according to claim 1, it is characterized in that,
Described output line voltage compensating circuit, comprises that a prefilter, a switching capacity filter and a voltage turn current circuit;
Described prefilter, the input of output line voltage compensating circuit described in input termination, the first input end of switching capacity filter described in output termination;
Described switching capacity filter, the input of output line voltage compensating circuit described in the second input termination, voltage turns the input of current circuit described in output termination;
Described voltage turns current circuit, the output of output line voltage compensating circuit described in output termination.
3. inverse-excitation type switch power-supply control chip is controlled on former limit according to claim 2, it is characterized in that,
Described prefilter, comprises the 4th resistance, the 4th electric capacity;
Described the 4th resistance, the input of prefilter described in a termination, the output of prefilter described in another termination;
Described the 4th electric capacity, the output of prefilter described in a termination, other end ground connection.
4. inverse-excitation type switch power-supply control chip is controlled on former limit according to claim 3, it is characterized in that,
Described switching capacity filter, comprises inverter, the 5th electric capacity, the 6th electric capacity, the first control switch, the second control switch;
Conducting when the first control switch, the second control switch are high at control end current potential, turn-offs when low;
Described inverter, the second input of switching capacity filter and the control end of described the first control switch described in input termination, the control end of the second control switch described in output termination;
Described the first control switch, the first input end of switching capacity filter described in a conduction current termination, one end of the 5th electric capacity and a conduction current end of described the second control switch described in another conduction current termination;
The 6th one end of electric capacity and the output of described switching capacity filter described in another conduction current termination of described the second control switch;
The other end ground connection of the other end of described the 5th electric capacity and described the 6th electric capacity.
5. inverse-excitation type switch power-supply control chip is controlled on former limit according to claim 4, it is characterized in that,
Described voltage turns current circuit, comprises operational amplifier, the 5th resistance, a PMOS pipe, the 2nd PMOS pipe, the 3rd NMOS pipe, the 4th NMOS pipe, the 5th NMOS pipe;
Described operational amplifier, voltage turns the input of current circuit described in positive input termination, the source electrode of the 3rd NMOS pipe described in negative input termination, the grid of the 3rd NMOS pipe described in output termination;
Described the 3rd NMOS pipe, drain electrode connects the drain electrode of a described PMOS pipe and the grid of grid and described the 2nd PMOS pipe;
The source electrode of a described PMOS pipe and described the 2nd PMOS pipe joins;
Described the 2nd PMOS pipe, drain electrode connects the drain electrode of described the 4th NMOS pipe and the grid of grid and described the 5th NMOS pipe;
The source ground of described the 4th NMOS pipe and described the 5th NMOS pipe;
Described the 5th NMOS pipe, drain electrode connects the output that described voltage turns current circuit;
Described the 5th resistance, the negative input end of operational amplifier described in a termination, other end ground connection.
6. an output line voltage compensating circuit, comprises that a prefilter, a switching capacity filter and a voltage turn current circuit;
Described prefilter, the input of output line voltage compensating circuit described in input termination, the first input end of switching capacity filter described in output termination;
Described switching capacity filter, the input of output line voltage compensating circuit described in the second input termination, voltage turns the input of current circuit described in output termination;
Described voltage turns current circuit, the output of output line voltage compensating circuit described in output termination.
7. output line voltage compensating circuit according to claim 6, is characterized in that,
Described prefilter, comprises the 4th resistance, the 4th electric capacity;
Described the 4th resistance, the input of prefilter described in a termination, the output of prefilter described in another termination;
Described the 4th electric capacity, the output of prefilter described in a termination, other end ground connection;
Described prefilter, time constant is arranged on hundred microsecond ranks.
8. output line voltage compensating circuit according to claim 7, is characterized in that,
Described switching capacity filter, comprises inverter, the 5th electric capacity, the 6th electric capacity, the first control switch, the second control switch;
Conducting when the first control switch, the second control switch are high at control end current potential, turn-offs when control end current potential is low;
Described inverter, the second input of switching capacity filter and the control end of described the first control switch described in input termination, the control end of the second control switch described in output termination;
Described the first control switch, the first input end of switching capacity filter described in a conduction current termination, one end of the 5th electric capacity and a conduction current end of described the second control switch described in another conduction current termination;
The 6th one end of electric capacity and the output of described switching capacity filter described in another conduction current termination of described the second control switch;
The other end ground connection of the other end of described the 5th electric capacity and described the 6th electric capacity.
9. output line voltage compensating circuit according to claim 8, is characterized in that,
Described voltage turns current circuit, comprises operational amplifier, the 5th resistance, a PMOS pipe, the 2nd PMOS pipe, the 3rd NMOS pipe, the 4th NMOS pipe, the 5th NMOS pipe;
Described operational amplifier, voltage turns the input of current circuit described in positive input termination, the source electrode of the 3rd NMOS pipe described in negative input termination, the grid of the 3rd NMOS pipe described in output termination;
Described the 3rd NMOS pipe, drain electrode connects the drain electrode of a described PMOS pipe and the grid of grid and described the 2nd PMOS pipe;
The source electrode of a described PMOS pipe and described the 2nd PMOS pipe joins;
Described the 2nd PMOS pipe, drain electrode connects the drain electrode of described the 4th NMOS pipe and the grid of grid and described the 5th NMOS pipe;
The source ground of described the 4th NMOS pipe and described the 5th NMOS pipe;
Described the 5th NMOS pipe, drain electrode connects the output that described voltage turns current circuit;
Described the 5th resistance, the negative input end of operational amplifier described in a termination, other end ground connection.
CN201420117412.9U 2014-03-14 2014-03-14 Primary control flyback switch power supply control chip and output line voltage compensating circuit Expired - Fee Related CN203813661U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201420117412.9U CN203813661U (en) 2014-03-14 2014-03-14 Primary control flyback switch power supply control chip and output line voltage compensating circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201420117412.9U CN203813661U (en) 2014-03-14 2014-03-14 Primary control flyback switch power supply control chip and output line voltage compensating circuit

Publications (1)

Publication Number Publication Date
CN203813661U true CN203813661U (en) 2014-09-03

Family

ID=51452360

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201420117412.9U Expired - Fee Related CN203813661U (en) 2014-03-14 2014-03-14 Primary control flyback switch power supply control chip and output line voltage compensating circuit

Country Status (1)

Country Link
CN (1) CN203813661U (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104569548A (en) * 2014-12-30 2015-04-29 上海贝岭股份有限公司 Line voltage detection circuit for switching power supply
CN112769331A (en) * 2021-03-24 2021-05-07 苏州力生美半导体有限公司 Output line compensation circuit without overcharging

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104569548A (en) * 2014-12-30 2015-04-29 上海贝岭股份有限公司 Line voltage detection circuit for switching power supply
CN112769331A (en) * 2021-03-24 2021-05-07 苏州力生美半导体有限公司 Output line compensation circuit without overcharging
CN112769331B (en) * 2021-03-24 2021-08-27 苏州力生美半导体有限公司 Output line compensation circuit without overcharging

Similar Documents

Publication Publication Date Title
CN102801300B (en) Primary-side feedback controlled switching power line loss compensating system and method
CN102904449B (en) The Circuit tuning of cable compensation for power converter is provided
CN103248207B (en) Constant-current and constant-voltage fly-back converter based on primary side feedback
CN101924471B (en) Method for constantly outputting current and device thereof
US20060109039A1 (en) Pulse width modulation device with a power saving mode controlled by an output voltage feedback hysteresis circuit
CN101752893A (en) Cable voltage drop compensation for battery chargers
CN105375798A (en) Self-adaptive sampling circuit, primary side feedback constant voltage system and switching power supply system
CN102201751B (en) Flyback power converter
CN102055341B (en) Control circuit of switching power supply and switching power supply
CN102035395A (en) Switching power supply device
CN105356746A (en) Conduction time generation circuit for power supply converter, and power supply converter
CN103929063A (en) Primary-side feedback control method and isolation converter based on primary-side feedback control
CN103414323A (en) Circuit for reducing turn-on time of current control type switch adjusting system
CN203466720U (en) Circuit reducing opening time in current control type switching regulating system
CN103219893B (en) Switch power controller and switching power circuit
CN104426370A (en) Power supply adapter and adaptive control circuit and adaptive control method of power supply adapter
CN102545552B (en) Matching circuit and large-power pulse power supply using same
CN203813661U (en) Primary control flyback switch power supply control chip and output line voltage compensating circuit
CN105305833A (en) Programmable frequency decrease circuit for a programmable power supply and method of switching frequency
CN204906189U (en) Low pressure high frequency switching power supply circuit
CN203522531U (en) Switching power supply based on primary side feedback control power switch chip
CN103929048A (en) Zero-crossing detection circuit of switching power supply
CN104253544A (en) Compensating circuit of control chip of switch power source
CN202178706U (en) AC-DC power conversion chip and power conversion circuit
CN203896028U (en) Multi-port usb charger

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20140903

Termination date: 20200314

CF01 Termination of patent right due to non-payment of annual fee