CN102957319A

CN102957319A - Pulse width modulation control circuit of power converter and control method thereof

Info

Publication number: CN102957319A
Application number: CN2011102507074A
Authority: CN
Inventors: 邱月美
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-08-29
Filing date: 2011-08-29
Publication date: 2013-03-06
Anticipated expiration: 2031-08-29
Also published as: CN102957319B

Abstract

The invention discloses a power supply conversion pulse width modulation control circuit and a control method thereof, the pulse width modulation control circuit comprises a virtual current ripple pulse width modulation circuit, the virtual current ripple pulse width modulation circuit is provided with an integration and direct current bias eliminating unit for inputting the phase node voltage signal and a signal reflecting output voltage, and generates a virtual current ripple parameter signal positioned at a direct current reference voltage level, a phase synthesizing unit for synthesizing the virtual current ripple parameter signal and an output voltage signal slope vector into a pulse width modulation parameter signal, a double-track reference voltage level generating unit for generating an upper direct current reference voltage level and a lower direct current reference voltage level, and the pulse width modulation parameter signal is compared with the upper direct current reference voltage level and the lower direct current reference voltage level to generate a pulse width modulation signal to be input into a driver. The invention can not only reduce the manufacturing cost of the power converter, but also reduce the volume of the power supply.

Description

Power supply changeover device pulse width modulating control circuit and control method thereof

Technical field

The present invention relates to a kind of power supply changeover device pulse width modulating control circuit and control method thereof, espespecially a kind ofly exempt from pulse width modulating control circuit and the control method thereof that compensation adjustment is stablized in the loop circuit.

Background technology

Power supply changeover device occupies very important status for general electronic equipment, its conversion electric power required voltage so that the electronic equipment start to be provided.And for the user, the vitality of electronic device works time often becomes when buying electronic equipment, and how therefore one of major consideration allow the electronic equipment can be in running order for a long time, become the main design goal of present power supply changeover device.

The design of power supply changeover device mainly is as main take exchange type power transducer (Switching Power Supplies) at present, the exchange type power transducer is by judging the required power output of load, output voltage or output current, utilize the means of pulse width modulation (PWM Pulse-width modulation), so that power supply changeover device, can more precisely be controlled the electric energy that exports load in output during electric energy and for load.Be difficult for when therefore the exchange type power transducer uses producing unnecessary waste of energy, and the loss of being saved electric energy.

See also the Patent Case of United States Patent (USP) notification number US6433525, it is proposed a kind of exchange type power transducer by Intersil company, mainly be to utilize the circuit of detecting inductive current to come the polarity of detecting current whether to change, and the time of arranging in pairs or groups and utilizing counter to come the current status of sensing lead to begin to change, and the output mode of selection electric energy, therefore when this exchange type power transducer is in the high current loads state, can select the pulse-width modulation adjusting control circuit to control the electric energy of output; And when the low current load state, can select sluggishness (ripples) control circuit to control the electric energy of output; Thereby reach the purpose of saving electric energy output, to prolong the time of electronic equipment continuous firing.

But, the counter of this kind exchange type power transducer changes at the current status of detecting load, between the electric energy output mode of selecting to be fit to, have a time drop, and cause the exchange type power transducer can't accurately cooperate the current status of load, suitable electric energy is provided, for example: when load is transformed into low current condition by high current status, time error when understanding because of counter works, cause this AC system power supply changeover device still to use sluggishness (ripples) adjusting control circuit to control the electric energy of output, cause the electric energy of output can't cooperate load required, and then cause the loss of electric energy.Therefore, this kind utilizes the exchange type power transducer of counter, and be relatively poor for the regulating effect of output electric energy, and can produce unnecessary electric energy loss.

Add the design of this kind exchange type power transducer, pulse width modulating control circuit is in order to be stablized out-put supply to load, must compensate adjustment to the power supply of input load, and need to arrange in pairs or groups sluggish (ripples) adjusting control circuit or other circuit, can't only reach the effect of stable control output voltage with single control circuit, and the design cost that causes this kind exchange type power transducer is higher, volume is larger, under the trend of constantly dwindling for present electronic product volume, the design of this kind power supply changeover device is real the necessity that must improve.

Summary of the invention

Purpose of the present invention provide a kind of and reduce transducer outlet side inductance, capacitance characteristic affects the pulse-width modulation control signal, and can have accurately control, the cost effect.

The transducer that the present invention relates to comprises at least one upper axle assemble, axle assemble once, and on being somebody's turn to do, lower axle assemble is electrically connected input power, and on being somebody's turn to do, lower axle assemble connects through the phase node, and the phase node be subjected to by the action of the driver of pulse-width modulation signal controlling so that on, lower axle assemble is done the switching over action, this phase node connects outputting inductance again, output capacitance, and control outputting inductance electric current is to output capacitance charging generation output voltage, wherein pulse width modulating control circuit of the present invention comprises virtual current ripple pulse-width modulation circuit, this virtual current ripple pulse-width modulation circuit has integration and Dc bias is eliminated the unit, the accurate generation unit of phase place synthesis unit and double track reference voltage position, this integration and Dc bias are eliminated the signal that aforementioned phase node voltage signal and reaction output voltage are inputted in the unit, and generation is positioned at the virtual current ripple parameter signal of DC reference voltage position standard, this phase place synthesis unit makes this virtual current ripple parameter signal and the synthetic pulse-width modulation parameter signal of output voltage signal slope vector, the accurate generation unit in this double track reference voltage position produces, lower DC reference voltage position is accurate, and this pulse-width modulation parameter signal and upper, lower DC reference voltage position standard relatively produces pulse-width modulation signal input aforementioned drives.

Virtual ripple current pulse-width modulation circuit of the present invention comprises accurate unit, a direct current reference voltage position, an integration and Dc bias elimination unit, a phase place synthesis unit, the accurate generation unit in a double track reference voltage position, a pulse-width modulation generation unit, and wherein accurate unit, DC reference voltage position provides one with reference to direct voltage position standard; This integration and Dc bias are eliminated the unit input and are connected aforementioned phase node voltage signal, and connection accurate unit, reference voltage position, and make the square wave of phase node voltage signal eliminate to form the triangular wave that is positioned at the direct current reference level through integration and Dc bias, but and this triangular wave slope reacting phase node voltage signal intensity; This phase place synthesis unit receives integrated waveform voltage and the converter output voltage of integration and Dc bias elimination unit output and makes the synthetic approximate triangle wave voltage of ratio stack generation, and this voltage is as the pulse-width modulation parameter signal; The input side of this accurate generation unit in double track reference voltage position connects accurate unit, DC reference voltage position again, and export the pulse-width modulation generation unit to, this accurate generation unit in double track reference voltage position is just producing the accurate voltage in corresponding reference voltage position again, on the double track of negative with difference, lower DC reference voltage, this pulse-width modulation generation unit input side connects phase place synthesis unit output and the accurate generation unit output in double track reference voltage position again, and make upper direct current reference level by the accurate generation unit of pulse-width modulation parameter signal and double track reference voltage position of phase place synthesis unit input, lower direct current reference level relatively, and produce the pulse-width modulation signal, and this pulse-width modulation signal enter drive is with in the control, lower axle assemble action.

Like this, the present invention comes the designing power supply transducer by this virtual ripple current pulse-width modulation circuit, do not need the component characteristic impedance of accurate control outputting inductance and filter capacitor to reach high stability and the design of easy-to-use power supply changeover device with the frequency response characteristic that adds the line adjustment error amplifier fully, no matter can make this power supply changeover device be in high load condition, when perhaps hanging down load condition, this virtual ripple current pulse-width modulation circuit all can reach the purpose of stabilized power supply output, not only be minimized the cost of manufacture of power supply changeover device, also can dwindle the volume of power supply unit, and solve the weak point of prior art.

The present invention also provides a kind of pulse-width modulation control method that compensation adjustment is stablized in the loop circuit of exempting from, and may further comprise the steps:

A. get the square wave voltage signal of phase node, and establish DC reference voltage position standard, this signal produces the virtual current ripple parameter signal that is positioned at DC reference voltage position standard through integration and Dc bias Processing for removing again;

B. will react the synthetic pulse-width modulation parameter signal with approximate triangular wave of output voltage signal and virtual current ripple parameter signal stack;

C. detect the pulse-width modulation parameter signal and produce the pulse-width modulation signal to control upper and lower axle assemble action.

It is accurate that wherein the detection mode of aforementioned c step is established the upper and lower DC reference voltage position of the accurate identical positive and negative voltage difference in corresponding DC reference voltage position, and the position that the rising of this pulse-width modulation parameter signal, decline wavelength-division are not positioned at upper and lower direct current reference level signal can produce the pulse-width modulation signal on time.

Description of drawings

Fig. 1 is circuit framework schematic diagram of the present invention.

Fig. 2 is virtual current ripple pulse-width modulation circuit box schematic diagram of the present invention.

Fig. 3 is virtual current ripple pulse-width modulation circuit of the present invention and action waveforms view.

Fig. 4 is action waveforms schematic diagram of the present invention.

Fig. 5 is that embodiments of the invention integration and Dc bias are eliminated the element circuit schematic diagram.

Fig. 5 A is the waveform schematic diagram of corresponding diagram 5 of the present invention.

Fig. 6 is that the another embodiment of the present invention Dc bias is eliminated the partial circuit schematic diagram.

Fig. 6 A is the waveform schematic diagram of corresponding diagram 6 of the present invention.

Fig. 6 B is the waveform schematic diagram of corresponding diagram 6 of the present invention.

Fig. 7 is embodiments of the invention phase place synthesis unit circuit diagram.

Fig. 8 is the accurate generation unit circuit diagram in embodiments of the invention double track reference voltage position.

Fig. 9 is embodiments of the invention pulse-width modulation element circuit schematic diagram.

Figure 10 is the heterogeneous application schematic diagram of the present invention.

Among the figure:

Axle assemble under the upper axle assemble Q2 of Q1

A phase node 91 drivers

92 outputting inductances, 93 output capacitances

94 resistance, 95 resistance

1 virtual current ripple pulse-width modulation circuit

Accurate unit, 2 DC reference voltage positions

3 integrations and Dc bias are eliminated the unit

4 phase place synthesis units

The accurate generation unit in 5 double track reference voltage positions

6 pulse-width modulation generation units

61 soft starting circuits, 31 integral parts

32 Dc biases are eliminated part 33 Dc biases and are eliminated part.

Embodiment

In order further to explain technical scheme of the present invention, the present invention will be described in detail below by specific embodiment.

Please refer to shown in Figure 1, it is the converter circuit Organization Chart that the present invention relates to, the transducer that the present invention relates to comprises axle assemble Q1 on, axle assemble Q2 once, and on, lower axle assemble Q1, Q2 is electrically connected input power VIN, and on being somebody's turn to do, lower axle assemble Q1, Q2 connects through phase node A, phase node A be subjected to driver 91 action so that on, lower axle assemble Q1, Q2 does the switching over action, and aforementioned lower axle assemble Q2 also can be diode (not indicating among the figure), this phase node A connects outputting inductance 92 again, output capacitance 93, and control outputting inductance 92 electric currents are to output capacitance 93 charging generation output voltage VO UT, and in the present embodiment, get

divider resistance

94,95 branch pressure voltage changes with detecting output voltage VO UT, the present invention has a virtual current ripple pulse-width modulation circuit 1 again, and this virtual current ripple pulse-width modulation circuit 1 aforementioned phase node A voltage signal of input and reaction output voltage VO UT signal, and export driver 91 to in the control, lower axle assemble Q1, Q2 does switch motion.

Please in the lump referring to figs. 1 through shown in Figure 4, virtual current ripple pulse-width modulation circuit 1 of the present invention comprises accurate unit 2, a direct current reference voltage position, one integration and Dc bias are eliminated unit 3, one phase place synthesis unit 4, the accurate generation unit 5 in one double track reference voltage position, one pulse-width modulation generation unit 6, wherein accurate unit 2, DC reference voltage position provides one with reference to the accurate VREF in direct voltage position (with reference to Fig. 4), integration and Dc bias are eliminated unit 3 inputs connection phase node A voltage VSW signal again, and connect accurate unit 2, DC reference voltage position, and tool integral part 31, Dc bias is eliminated part 32.

As shown in Figure 3 and Figure 4, the square wave of this phase node A voltage signal is eliminated the triangular wave Vint that unit 3 formation are positioned at the direct current reference level through integration and Dc bias, its waveform as shown in Figure 4, and but this triangular wave slope reacting phase node A voltage signal changes, and the present embodiment Vint waveform shown in Figure 4 is anti-phase kenel, also can be the homophase kenel.

Phase place synthesis unit 4 receives integrated waveform voltage that integrations and Dc bias eliminate unit 3 outputs and transducer and feedbacks detecting output voltage V FB and do the ratio stack and synthesize triangle wave voltage, VEA among its waveform such as Fig. 4, and this VEA voltage is as the pulse-width modulation parameter signal, and VEA is the corresponding VSW phase wiggles of the anti-phase rear formation of Vint among the figure.

Accurate generation unit 5 input sides in double track reference voltage position connect accurate unit 2, DC reference voltage position, and exporting pulse-width modulation generation unit 6 to, the accurate generation unit 6 in this double track reference voltage position produces the upper and lower direct current reference level of double track VREF+, the VREF-such as the positive and negative identical difference of the corresponding accurate VREF voltage in reference voltage position of Fig. 4 again.

Pulse-width modulation generation unit 6 input sides connect phase place synthesis unit 4 outputs and accurate generation unit 5 outputs in double track reference voltage position, and the upper direct current reference level VREF+, the lower direct current reference level VREF-that are inputted by the accurate generation unit 5 of pulse-width modulation parameter signal VEA and double track reference voltage position of phase place synthesis unit 4 inputs compare, and produce the pulse-width modulation signal, and this pulse-width modulation signal enter drive 91 is to control upper and lower axle assemble Q1, Q2 action.

See also Fig. 4, transducer reset voltage of the present invention is VFB, and this VFB voltage when reducing in the T1 time on axle assemble Q1 conducting, and the voltage of VSW raises, and make, lower axle assemble Q1, the VSW voltage of Q2 phase node A is VIN voltage, the again T2 time output voltage VO UT at present axle assemble Q2 conducting that raises, and VSW voltage namely reduces, and phase node A voltage is earth potential, and since the internal resistance of output capacitance 93 characteristics (indicating among the figure) by outputting inductance 92 current charges, this feedbacks the ripple of VFB to should the different peak values of output capacitance 93 characteristic tools, this Vint is that integration and Dc bias are eliminated unit 3 output voltages again, and can be corresponding VSW voltage produce the triangle wave voltage of tool reference voltage VREF position standard, and the triangle wave voltage of the present embodiment is the anti-phase of VSW voltage, also can be the homophase design, VEA is that phase place synthesis unit 4 input converter reset voltage VFB and Vint voltage superpose and reverse pulse-width modulation parameter voltage again, and because of this VEA be that aforementioned Vint waveform is anti-phase again, thereby can produce corresponding VSW voltage phase wiggles, this VREF+ again, VREF-is for just being positioned at reference voltage VREF, negative direct current reference level voltage, and VEA voltage waveform slope of the present invention can more react the change in voltage of VFB, and can produce approximate triangular wave, thereby when the VEA voltage drop to the B position of T1 time and VREF-handing-over or VEA voltage can make the pulse-width modulation unit produce the pulse-width modulation signal when rising to the C position of T2 time and VREF+ handing-over to reach with control driver 91, lower axle assemble Q1, the Q2 action, and make the present invention can accurately react the variation of output pressure to promote output voltage stability.

The integration that the present invention relates to and Dc bias are eliminated unit 3, phase place synthesis unit 4, the accurate generation unit 5 in double track reference voltage position, pulse-width modulation generation unit 6 can be the various aforementioned functional design of reaching, extremely shown in Figure 5 such as Fig. 1, the integration that the present invention relates to and Dc bias are eliminated unit 3 and are had integral part 31 and Dc bias elimination part 32, and integral part 31 tools the first operational amplifier OP1, and its inverting input connects the first resistance R 1 and is electrically connected with phase node a-signal SW, inverting input connects the second resistance R 2 and Dc bias and eliminates the output bias of part 32 and be connected again, be connected the first capacitor C 1 between the output of the first operational amplifier OP1 and inverting input again, and integration time constant is by R1, C1 determines, and its in-phase input end connects the DC reference voltage accurate unit 2 output contact REF in position, and the phase node A voltage VSW integration of square wave can be formed triangular signal, it is accurate that bias produces voltage capable of regulating output direct current position again, Dc bias is eliminated part 32 tool integrating circuit again, error amplifying circuit, and this integrating circuit input connects the output of integral part 31, error amplifying circuit connects output and the DC reference voltage position accurate unit output contact REF of integrating circuit again, so that the duty cycle square wave of integral part 31 corresponding phase node a-signal VSW forms the accurate triangular wave in different direct currents position (consulting Fig. 3), and can form corresponding direct current position quasi wave shape through integrating circuit, and by error amplifying circuit the accurate VREF in DC reference voltage position of this accurate unit 2 of direct current position quasi wave shape and DC reference voltage position is compared again, and its dc error amount is through amplifying again input integral part 31, so that the accurate triangle wave voltage in integral part 31 output different direct currents positions can be adjusted to the triangular wave Vint that is positioned at the accurate VREF in DC reference voltage position, and this Dc bias elimination part 32 has the second operational amplifier OP2, the 3rd operational amplifier OP3, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the second capacitor C 2, and the inverting input of this second operational amplifier OP2 connects the 3rd resistance R 3 and is connected with the output of the first operational amplifier OP1, and the 4th resistance R 4 in parallel and the second capacitor C 2 between its inverting input and output, its in-phase input end connects the output contact REF of accurate unit 2, DC reference voltage position again, and makes the second operational amplifier OP2 form integrating circuit; The inverting input of the 3rd operational amplifier OP3 connects the 5th resistance R 5 and is connected with the output of the second operational amplifier OP2 again, and being connected the 6th resistance R 6 between its inverting input and output, its in-phase input end connects the output contact REF of accurate unit 2, DC reference voltage position again.

See also Fig. 5 and Fig. 5 A, when Vint of the present invention exported without dc error, VCR (the output capacitance 93 interior resistance voltages) triangular wave that Vint is output as behind the VSW integration added that the VREF position is accurate; When aforementioned circuit makes the triangular signal of integral part 31 inputs the second operational amplifier OP2 that dc error be arranged, can eliminate VCR via the anti-phase integration of the second operational amplifier OP2 again and form corresponding dc waveform signal Vdet output, again the dc waveform voltage of this second operational amplifier OP2 output input the 3rd operational amplifier OP3 and with the reference level voltage ratio, and after error is amplified, become again the first operational amplifier OP1 inverting input of feed-in integral part 31 of Vbias voltage, thereby make the VCR triangular wave behind integration and the Dc bias elimination unit 3 output VSW integrations add that the position standard of VREF forms the virtual ripple current triangular signal Vint of corresponding DC reference voltage position standard.

See also Fig. 1 to Fig. 6, integral part 31 same Fig. 5 of another embodiment of the present invention, and Dc bias is eliminated part 33 by comparison circuit, anti-phase integrator forms, and the comparison circuit of the present embodiment has four-operational amplifier OP4, and its inverting input connects the output of integral part 31, its in-phase input end connects the DC reference voltage accurate unit 2 output contact REF in position again, integrating circuit has the 7th resistance R 7 again, the 3rd capacitor C 3, large device OP5 is imitated in the 5th computing, and the four-operational amplifier OP4 output that the inverting input of the 5th operational amplifier OP5 connects the 7th resistance R 7 and comparison circuit is connected, this inverting input connects the 3rd capacitor C 3 and is connected with the output of the 5th operational amplifier OP5 again, the in-phase input end of the 5th operational amplifier OP5 connects the DC reference voltage accurate unit 2 output contact REF in position again, so that when Vint exports without dc error, the VCR triangular wave that Vint is output as behind the VSW integration adds that the position of VREF is accurate, Fig. 6 and for example, shown in Fig. 6 A and Fig. 6 B, the integrated waveform that integral part 31 receives when Vint output has dc error is take DC reference voltage position standard as direct current reference level VREF, compare through comparison circuit and direct current reference level VREF, the square wave that produces is shown in Fig. 6 A dotted line, if the duty ratio of direct current root-mean-square value then this square wave identical with reference level voltage is 50%, this comparison circuit output Vcomp is 2x reference level voltage, K=2 wherein, behind the integrating circuit integration, produce again the Vbias voltage of corresponding Vint dc error amount, and shown in Fig. 5 and Fig. 6 B, this Vbias voltage can be inputted the bias end points of aforementioned integral part 31, it is accurate to adjust integral part 31 output direct current positions that its phase place can be offseted the dc error of Vint, and form the triangular wave Vint signal that is positioned at corresponding DC reference voltage position standard.

Please refer to Fig. 1 to Fig. 4 and Fig. 7, phase place synthesis unit 4 has error amplifier, and input side input integral and Dc bias elimination unit 3 output voltage V int and transducer reset voltage VFB, and through the synthetic output pulse width modulation parameter signal that superposes, and the present embodiment tool the 6th operational amplifier OP6, and the inverting input of the 6th operational amplifier OP6 connects the 8th resistance R 8 and the integration Dc bias is eliminated unit 3 output contact Vint, this inverting input connects the 9th resistance R 9 and is connected with the output of the 6th operational amplifier OP6 again, and this inverting input and the 8th resistance R 8,9 tool phases of the 9th resistance R node, the in-phase input end of the 6th operational amplifier OP6 connects transducer reset voltage contact FB again, and capable of regulating the 8th resistance R 8, the resistance of the 9th resistance R 9 is got output voltage proper proportion and the transducer reset voltage VFB of corresponding integration and Dc bias elimination unit 3, the desirable Vint 1/20 corresponding VFB voltage of preferably, and this aforesaid voltage and transducer reset voltage VFB stack are synthesized, and make integration and Dc bias eliminate the output voltage triangular signal slope of unit 3 and the synthetic output pulse width parameter signal VEA that forms of variation slope vector of transducer reset voltage VFB.

See also Fig. 1 to Fig. 4 and Fig. 8, this accurate generation unit 5 in double track reference voltage position has two comparison circuits, and an input of this two comparison circuit connects direct current reference level signal, and this two comparison circuits contact resistance, and the resistance by resistance is set the upper and lower direct current reference level of exporting respectively the accurate identical positive negative difference in corresponding DC reference voltage position.In the present embodiment, it has the 7th operational amplifier OP7, the 8th operational amplifier OP8, and the 7th operational amplifier OP7, the in-phase input end of the 8th operational amplifier OP8 connects the DC reference voltage accurate unit 2 output contact REF in position, and the inverting input of the 7th operational amplifier OP7 connects the tenth resistance R 10 ground connection, and inverting input connects the 11 resistance R 11 and is connected with output, and the upper direct current reference level VREF+ of the 7th operational amplifier OP7 output generation, the inverting input of the 8th operational amplifier OP8 connects the 12 resistance R 12 and is connected with the output of the 7th operational amplifier OP7 again, and this inverting input connects the 13 resistance R 13 and is connected with the 8th operational amplifier OP8 output, and the inverting input of the 12 resistance R 12 and the 13 resistance R 13 and the 8th operational amplifier OP8 has the phase node, and the output that makes the 8th operational amplifier OP8 produces lower direct current reference level VREF-, and should the upper accurate VREF+ in DC reference voltage position be VREF+ (VREF * R11/R10), descending again the accurate VREF-in DC reference voltage position is [(VREF+-VREF) *-1]+VREF, if establishing reference level VREF voltage is 1V, the tenth resistance R 10 is 99K, the 11 resistance R 11 resistances are 1K, VREF+=1+ (1 * 1K/99K)=1.01V, again VREF-=[(1.01V-1V then) *-1]+1V=0.99V.

Please refer to Fig. 1 to Fig. 4 and Fig. 9, pulse-width modulation generation unit 6 tools two comparison circuits of the present invention, and this comparison circuit input connects pulse-width modulation parameter signal EA and upper direct current reference level REF+, another comparison circuit input connects the pulse-width modulation parameter with signal EA and lower direct current reference level REF-, and the square-wave signal of two comparison circuit output formation reaction pulse-width modulation parameter signal slope variation, and this square wave signal can amplify and cooperation soft starting circuit generation pulse-width modulation signal through flip-flop, and the present embodiment has the 9th operational amplifier OP9, the tenth operational amplifier OP10, the RS flip-flop, soft starting circuit 61, and this soft starting circuit 61 is the known techniques of power supply changeover device, no longer give stating more, the in-phase input end of the 9th operational amplifier OP9 connects the pulse-width modulation parameter signal EA of phase place synthesis unit 4 inputs again, the inverting input of the 9th operational amplifier OP9 connects upper direct current reference level REF+ again, and the pulse-width modulation parameter signal EA of the tenth operational amplifier OP10 inverting input connection phase place synthesis unit 4 inputs, and its in-phase input end connects lower direct current reference level REF-, the 9th operational amplifier OP9 again, the output of the tenth operational amplifier OP10 connects respectively the R end of RS flip-flop, the S end, the Q of RS flip-flop end is connected the AND lock with the output of soft starting circuit 61 again, and this AND lock output produces pulse-width modulation signal PWM, so that rising to punctual the 9th operational amplifier OP9 in VREF+ position, the voltage waveform slope of VEA exports a high potential square wave, and to make RS flip-flop output Q be that electronegative potential is to reduce converter output voltage, the voltage waveform slope of VEA is reduced to punctual the tenth operational amplifier OP10 in VREF-position and exports a high potential square wave again, and to make RS flip-flop output Q be that high potential is to promote converter output voltage.

Please refer to Figure 10, the pulse-width modulation framework of tool virtual current ripple pulse-width modulation circuit 1 of the present invention and driver 91 and upper and lower axle assemble Q1, Q2 can give parallel connection, and connect respectively outputting inductance 92 and be connected with same output capacitance 93 and do heterogeneous configuration, and make the present invention can cooperate loading demand to promote output current, and be that two groups of pulse-width modulation frameworks are in parallel shown in the figure, also can cooperate load to make two groups of above pulse-width modulation frameworks and be arranged in parallel.

Aforementioned circuit of the present invention is illustration of the present invention, is not as claim restriction of the present invention, and all change according to the equivalence shown in the spirit of the present invention also should belong to the contained lid of the present patent application claim.

Claims

1. A power converter pulse width modulation control circuit, the power converter includes at least one upper bridge component and a lower bridge component, and the upper and lower bridge components are electrically connected to the input power supply, and the upper and lower bridge components are passed through The phase node is connected, and the parallel phase node is operated by the driver controlled by the pulse width modulation signal to make the upper and lower bridge components switch. In addition, the phase node is connected to the output inductor and output capacitor, and the output inductor current is controlled to charge the output capacitor. Generate an output voltage; it is characterized in that the pulse width modulation control circuit includes a virtual current ripple pulse width modulation circuit, and the virtual current ripple pulse width modulation circuit has an integration and DC bias elimination unit, a phase synthesis unit and A dual-rail reference voltage level generation unit, the integration and DC bias elimination unit inputs the aforementioned phase node voltage signal and the signal reflecting the output voltage, and generates a virtual current ripple parameter signal at the DC reference voltage level, and the phase synthesis unit enables The virtual current ripple parameter signal and the slope vector of the output voltage signal synthesize a pulse width modulation parameter signal, and the dual-rail reference voltage level generation unit generates an upper and lower DC reference voltage level, and the pulse width modulation parameter signal is combined with the upper and lower DC reference voltage levels. The lower DC reference voltage level is compared to generate a pulse width modulation signal that is input to the aforementioned driver.

2. The power converter pulse width modulation control circuit according to claim 1, wherein the virtual current ripple pulse width modulation circuit further comprises a DC reference voltage level unit and a pulse width modulation generating unit , the DC reference voltage level unit provides a reference DC voltage level; the input terminal of the integration and DC bias elimination unit is connected to the aforementioned phase node voltage signal, and connected to the reference voltage level unit, and makes the square wave of the phase node voltage signal After integration and DC bias elimination, a triangular wave at the DC reference level is formed. The slope of the triangular wave can reflect the change of the phase node voltage signal. The phase synthesis unit receives the integrated waveform voltage output by the integration and DC bias elimination unit and the output voltage of the converter. Perform proportional superposition to generate a synthetic approximate triangular wave voltage, and use the voltage as a pulse width modulation parameter signal; the input side of the dual-rail reference voltage level generating unit is connected to a DC reference voltage level unit, and is output to the pulse width modulation generating unit; The dual-rail reference voltage level generation unit generates a dual-rail DC reference voltage unit corresponding to the positive and negative reference voltage level voltage difference; the input side of the pulse width modulation generation unit is connected to the output terminal of the phase synthesis unit and the dual-rail reference voltage level generation unit The output terminal of the unit, and compare the pulse width modulation parameter signal input by the phase synthesis unit with the upper DC reference level and the lower DC reference level of the dual-rail reference voltage level generation unit, and generate a pulse width modulation signal.

3. The power converter pulse width modulation control circuit as claimed in claim 2, wherein the integration and DC bias elimination unit has an integration part and a DC bias elimination part, and the integration part connects the upper and lower bridge components The signal integration of the square wave at the phase node forms a triangular wave signal. The DC bias elimination part has an integration circuit and an error amplifier circuit. The input terminal of the integration circuit is connected to the output terminal of the integration part. The reference voltage level unit outputs, and makes the output of the integral part correspond to the phase node signal of the upper and lower bridge components. The corresponding DC level waveform can be formed through the integration circuit, and then the error amplifier circuit makes the DC level waveform and the DC reference voltage level The DC reference voltage level of the unit is compared, and the DC error voltage is amplified and then input to the integral part, so that the triangular wave voltage output by the integral part at different DC levels can be adjusted to a triangular wave at the DC reference voltage level.

4. The power converter pulse width modulation control circuit according to claim 2, wherein the integration and DC bias elimination unit has an integration part and a DC bias elimination part, and the integration part connects the upper and lower bridge components The signal integration of the square wave at the phase node forms a triangular wave signal. The DC bias elimination part is composed of a comparison circuit and an integration circuit. The input terminal of the comparison circuit is connected to the output signal of the integration part and the output signal of the DC reference voltage level unit. The integration circuit The input terminal is connected to the comparison circuit and the output signal of the DC reference voltage level unit, so that the integral waveform received by the integral part takes the DC reference voltage level as the DC reference level, and is compared with the DC reference level voltage by the comparison circuit, and then integrated by the integration circuit Then generate a DC error output voltage corresponding to the DC reference voltage level corresponding to the reference level voltage, and input the voltage into the aforementioned integration part to adjust the output DC level of the integration part, and form a triangle wave at the corresponding DC reference voltage level.

5. The pulse width modulation control circuit of a power converter as claimed in claim 2, wherein the phase synthesizing unit has an error amplifier, and the input side of the error amplifier is input to an integration and DC bias elimination unit and a converter output back Supplied voltage, and output pulse width modulation parameter signal through superposition synthesis.

6. The power converter pulse width modulation control circuit according to claim 2, wherein the dual-rail reference voltage level generation unit has two comparison circuits, and one input terminal of the two comparison circuits is connected to a DC reference level, The two comparator circuits are connected with resistors, and the resistance values of the resistors are used to set the upper and lower DC reference levels corresponding to the same positive and negative difference of the DC reference voltage levels.

7. The power converter pulse width modulation control circuit according to claim 2, wherein the pulse width modulation generating unit has two comparison circuits, and the input terminal of the comparison circuit is connected to the pulse width modulation parameter signal and The upper DC reference level signal is connected to the input terminal of the other comparator circuit with the PWM parameter signal and the lower DC reference level signal, and the output of the two comparator circuits forms a square wave signal reflecting the slope change of the PWM parameter signal.

8. The pulse width modulation control circuit of a power converter according to claim 2, wherein the pulse width modulation structure composed of the virtual current ripple pulse width modulation circuit, the driver, and the upper and lower bridge components is connected in parallel , and respectively connect the output inductor and the same output capacitor for multi-phase configuration.

9. A pulse width modulation control method for a power converter, the power converter includes at least one upper bridge component and a lower bridge component, and the upper and lower bridge components are electrically connected to the input power supply, and the upper and lower bridge components are passed through The phase node is connected, and the parallel phase node is operated by the driver controlled by the pulse width modulation signal to make the upper and lower bridge components switch. In addition, the phase node is connected to the output inductor and output capacitor, and the output inductor current is controlled to charge the output capacitor. Generate an output voltage; it is characterized in that, the pulse width modulation control method comprises the following steps:

a. Take the square wave voltage signal of the phase node, and set the DC reference voltage level, and the signal is processed by integration and DC bias elimination to generate a virtual current ripple parameter signal at the DC reference voltage level;

b. Superimpose the response output voltage signal and the virtual current ripple parameter signal to synthesize a pulse width modulation parameter signal with an approximate triangular wave;

c. Detect the pulse width modulation parameter signal and generate a pulse width modulation signal to control the action of the upper and lower bridge components.

10. The pulse width modulation control method of a power converter as claimed in claim 9, wherein the detection method of the aforementioned step c is provided with an upper and a lower DC reference voltage corresponding to the same positive and negative voltage difference of the DC reference voltage level. The voltage level, and the pulse width modulation signal can be generated when the rising and falling waves of the pulse width modulation parameter signal are respectively at the level of the upper and lower DC reference level signals.