CN115395775A - Slope compensation circuit and PWM modulation circuit - Google Patents

Slope compensation circuit and PWM modulation circuit Download PDF

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Publication number
CN115395775A
CN115395775A CN202211213340.3A CN202211213340A CN115395775A CN 115395775 A CN115395775 A CN 115395775A CN 202211213340 A CN202211213340 A CN 202211213340A CN 115395775 A CN115395775 A CN 115395775A
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China
Prior art keywords
circuit
slope compensation
resistor
target
switch tube
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CN202211213340.3A
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Chinese (zh)
Inventor
刘鸿志
耿程飞
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Invt Power Electronics Suzhou Co ltd
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Invt Power Electronics Suzhou Co ltd
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Priority to CN202211213340.3A priority Critical patent/CN115395775A/en
Publication of CN115395775A publication Critical patent/CN115395775A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • H02M1/092—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices the control signals being transmitted optically
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K7/00—Modulating pulses with a continuously-variable modulating signal
    • H03K7/08—Duration or width modulation ; Duty cycle modulation

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The application discloses slope compensation circuit belongs to power electronics technical field, and this circuit includes: the voltage detection module is used for detecting the input voltage of the target topology circuit to obtain a target input voltage; the target topological circuit is a circuit with subharmonic oscillation; and the slope compensation module is used for outputting a slope compensation signal and adaptively adjusting the strength of the slope compensation signal so as to enable the strength of the slope compensation signal to form a negative correlation with the target input voltage and eliminate subharmonic oscillation of the target topological circuit. The slope compensation circuit can be suitable for the whole input voltage range with the subharmonic oscillation circuit topology on the premise of not influencing the working performance of the circuit topology. Correspondingly, the PWM modulation circuit provided by the application has the beneficial effects.

Description

Slope compensation circuit and PWM modulation circuit
Technical Field
The invention relates to the technical field of power electronics, in particular to a slope compensation circuit and a PWM (pulse-width modulation) circuit.
Background
For a circuit topology with subharmonic oscillation, the subharmonic oscillation in the circuit topology can be suppressed by adding the slope compensation circuit, but the existing slope compensation circuit cannot be well adapted to the whole input voltage range of the circuit topology, and the application of the slope compensation circuit in the whole input voltage range of the circuit topology is met by sacrificing some performance indexes of the circuit topology under many conditions.
In the prior art, the following three ramp compensation circuits are generally used to suppress the subharmonics generated by the oscillating circuit topology with subharmonics. The first one is to add a capacitor of pF level between the oscillation pin and the current detection pin of the power management chip to realize slope compensation of the circuit topology, however, the slope compensation circuit is only suitable for the circuit topology with narrow input voltage range and can not be suitable for the circuit topology with large input voltage range; the second method is to add an NPN triode between an oscillation pin and a current detection pin of a power management chip to realize slope compensation of the subharmonic oscillation circuit topology, but the method can influence the loading capacity of the circuit topology; the third is to divide the input voltage with the subharmonic oscillation circuit topology into a plurality of gears, and design the slope compensation intensity of the slope compensation circuit into a plurality of gears, so that the input voltage with different circuit topologies can correspond to slope compensation with different intensities, but the method has the problem of back-and-forth switching of the slope compensation shift dividing point, which seriously affects the stability of the circuit topology in the working process. At present, no effective solution exists for the technical problem.
Disclosure of Invention
In view of the above, the present invention provides a slope compensation circuit and a PWM modulation circuit, so that the slope compensation circuit can be applied to the whole input voltage range with the sub-harmonic oscillation circuit topology without affecting the operation performance of the circuit topology. The specific scheme is as follows:
a slope compensation circuit, comprising:
the voltage detection module is used for detecting the input voltage of the target topology circuit to obtain a target input voltage; wherein the target topology circuit is a circuit with subharmonic oscillation;
and the slope compensation module is used for outputting a slope compensation signal and adaptively adjusting the intensity of the slope compensation signal so as to enable the intensity of the slope compensation signal to form a negative correlation with the target input voltage and eliminate subharmonic oscillation of the target topological circuit.
Preferably, the slope compensation module is a compensation circuit which is built by a transistor, an optical coupler, an operational amplifier or a controllable precise voltage-stabilizing source.
Preferably, the slope compensation module includes: the optical coupler comprises a first switch tube, a second switch tube, an optical coupler, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor and a power management chip;
the first end of the first switch tube is connected with the first input end of the optical coupler, the second input end of the optical coupler is connected with the first end of the first resistor, the first output end of the optical coupler is respectively connected with the first end of the second resistor and the first end of the second switch tube, the second output end of the optical coupler is connected with the first end of the third resistor, the second end of the third resistor is respectively connected with the second end of the second resistor and the CURRENT terminal of the power management chip, the second end of the first resistor is connected with the second end of the second switch tube, the first end of the fourth resistor and the VREF terminal of the power management chip, the control end of the second switch tube is respectively connected with the second end of the fourth resistor, the first end of the first capacitor and the RC/CT terminal of the power management chip, the second end of the first capacitor is grounded, and the VFB terminal of the power management chip is grounded;
correspondingly, the control terminal of the first switching tube is configured to receive the target input voltage, the OUT terminal of the power management chip is an output terminal of the slope compensation module, the CURRENT terminal of the power management chip is configured to receive the slope compensation signal, and the CURRENT of the target topology circuit is fed back to the CURRENT terminal of the power management chip through the target port in the target topology circuit.
Preferably, the first switch tube is specifically a PNP triode, and the second switch tube is specifically an NPN triode;
correspondingly, the base of the PNP triode is the control end of the first switch tube, the emitter of the PNP triode is the first end of the first switch tube, the collector of the PNP triode is the second end of the first switch tube, the base of the NPN triode is the control end of the second switch tube, the collector of the NPN triode is the first end of the second switch tube, and the emitter of the NPN triode is the second end of the second switch tube.
Preferably, the method further comprises the following steps: a second capacitor;
and the first end of the second capacitor is connected with the second end of the second resistor, and the second end of the second capacitor is grounded.
Preferably, the voltage detection module includes: a fifth resistor and a sixth resistor;
the second end of the fifth resistor is connected with the first end of the sixth resistor and the control end of the first switching tube respectively;
correspondingly, the first end of the fifth resistor is used for receiving the input signal of the target topology circuit, and the second end of the sixth resistor is grounded.
Preferably, the method further comprises the following steps: a seventh resistor;
the first end of the seventh resistor is connected with the CURRENT end of the power management chip.
Preferably, the optical coupler is a linear optical coupler.
Preferably, the target topology circuit is a BUCK circuit, a flyback circuit or a forward circuit.
Correspondingly, the invention also discloses a PWM modulation circuit, which comprises the slope compensation circuit disclosed in the foregoing.
Therefore, in the slope compensation circuit provided by the invention, since the strength of the slope compensation signal output by the slope compensation module can form a negative correlation with the target input voltage of the target topology circuit detected by the voltage detection module, the slope compensation signal output by the slope compensation module can be adaptively changed along with the change of the input voltage of the target topology circuit. Compared with the prior art, the slope compensation circuit is not limited by the influence of the input voltage range of the target topological circuit, and the working performance of the target topological circuit is not influenced. Therefore, the slope compensation circuit can be applied to the whole input voltage range with the subharmonic oscillation circuit topology on the premise of not influencing the working performance of the circuit topology. Correspondingly, the PWM modulation circuit provided by the invention also has the beneficial effects.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a structural diagram of a slope compensation circuit according to an embodiment of the present invention;
fig. 2 is a structural diagram of a slope compensation module according to an embodiment of the present invention;
fig. 3 is a block diagram of another slope compensation circuit according to an embodiment of the present invention;
FIG. 4 is a schematic diagram illustrating the slope compensation of the BUCK circuit by the slope compensation circuit shown in FIG. 3.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a structural diagram of a slope compensation circuit according to an embodiment of the present invention, the circuit includes:
the voltage detection module 11 is configured to detect an input voltage of the target topology circuit to obtain a target input voltage; the target topological circuit is a circuit with secondary slope oscillation;
and the slope compensation module 12 is configured to output a slope compensation signal, and adaptively adjust the strength of the slope compensation signal, so that the strength of the slope compensation signal forms a negative correlation with the target input voltage, and the subharmonic oscillation of the target topology circuit is eliminated.
In the present embodiment, a slope compensation circuit is provided, by which the slope compensation circuit can be applied to the whole input voltage range with the sub-harmonic oscillation circuit topology without affecting the operation performance of the circuit topology.
The slope compensation circuit is provided with a voltage detection module 11 and a slope compensation module 12, wherein the voltage detection module 11 is used for detecting an input voltage of a target topology circuit to obtain a target input voltage. In practical applications, the voltage detection module 11 may be set as a resistance voltage divider circuit to detect the input voltage of the target topology circuit, the voltage detection module 11 may be set as an operational amplifier to detect the input voltage of the target topology circuit, or the voltage detector may be directly used to detect the input voltage of the target topology circuit.
The slope compensation module 12 is configured to output a slope compensation signal, and adaptively adjust the strength of the slope compensation signal, so that the strength of the slope compensation signal and the target input voltage of the target topology circuit form a negative correlation relationship, thereby eliminating the subharmonic oscillation of the target topology circuit. It can be thought that, when the strength of the slope compensation signal output by the slope compensation module 12 can form a negative correlation with the target input voltage of the target topology circuit, the slope compensation signal output by the slope compensation module 12 can change in real time along with the change of the target topology circuit input voltage, which is equivalent to that the slope compensation module 12 can adaptively adjust the strength of the slope compensation signal output by the slope compensation module according to the target topology circuit input voltage, so that the working performance of the target topology circuit is not affected in this setting mode. Moreover, since the strength of the slope compensation signal output by the slope compensation module 12 can form a negative correlation with the target input voltage of the target topology circuit, the slope compensation circuit can be applied to the whole input voltage range of the target topology circuit.
Specifically, in practical application, the slope compensation module 12 may be built by using a transistor, an optical coupler, an operational amplifier or a controllable precision voltage regulator, because the building manner of the slope compensation module 12 is common knowledge of those skilled in the art, specific structures of the slope compensation module 12 are not described in detail here.
In addition, in practical application, the target topology circuit can be set as a BUCK circuit (BUCK converter circuit), a flyback circuit or a forward circuit, and since these circuits are typically circuits with subharmonic oscillation, the slope compensation circuit provided by the present application can be used to eliminate the subharmonic oscillation of the BUCK circuit, the flyback circuit or the forward circuit in practical operation, so that the BUCK circuit, the flyback circuit or the forward circuit can work better.
As can be seen, in the slope compensation circuit provided in this embodiment, since the strength of the slope compensation signal output by the slope compensation module can form a negative correlation with the target input voltage of the target topology circuit detected by the voltage detection module, the slope compensation signal output by the slope compensation module can adaptively change along with the change of the input voltage of the target topology circuit. Compared with the prior art, the slope compensation circuit is not limited by the influence of the input voltage range of the target topological circuit, and the working performance of the target topological circuit is not influenced. Therefore, the slope compensation circuit can be applied to the whole input voltage range with the subharmonic oscillation circuit topology on the premise of not influencing the working performance of the circuit topology.
Based on the above embodiments, the present embodiment further describes and optimizes the technical solution, please refer to fig. 2, and fig. 2 is a structural diagram of a slope compensation module according to an embodiment of the present invention. As a preferred embodiment, the slope compensation circuit includes: the circuit comprises a first switch Q1 tube, a second switch Q2 tube, an optocoupler PC, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1 and a power management chip U;
the first end of the first switch Q1 tube is connected with the first input end of the optocoupler PC, the second input end of the optocoupler PC is connected with the first end of the first resistor R1, the first output end of the optocoupler PC is respectively connected with the first end of the second resistor R2 and the first end of the second switch Q2 tube, the second output end of the optocoupler PC is connected with the first end of the third resistor R3, the second end of the third resistor R3 is respectively connected with the second end of the second resistor R2 and the CURRENT end of the power management chip U, the second end of the first resistor R1 is connected with the second end of the second switch Q2 tube, the first end of the fourth resistor R4 and the VREF end of the power management chip U, the control end of the second switch Q2 tube is respectively connected with the second end of the fourth resistor R4, the first end of the first capacitor C1 and the RC/CT end of the power management chip U, the second end of the first capacitor C1 is grounded, and the B end of the VFU is grounded;
correspondingly, the control end of the first switch Q1 is used for receiving the target input voltage, the OUT end of the power management chip is the output end of the slope compensation module, the CURRENT end of the power management chip is used for receiving the slope compensation signal, and the CURRENT of the target topology circuit is fed back to the CURRENT end of the power management chip through the target port in the target topology circuit.
In the slope compensation circuit provided in this embodiment, the control terminal of the first switching tube Q1 is configured to receive a target input voltage of a target topology circuit. In practical applications, the first switch tube Q1 and the second switch tube Q2 may be configured as MOS transistors (Metal Oxide Semiconductor Field Effect transistors), IGBTs (Insulated Gate Bipolar transistors), or triodes.
Specifically, in this embodiment, the first switch tube Q1 may be configured as a PNP triode, and the second switch tube Q2 may be configured as an NPN triode, because the triode has a lower cost compared with other types of switch tubes, when the first switch tube Q1 is configured as the PNP triode and the second switch tube Q2 is configured as the NPN triode, the setting cost required by the slope compensation circuit may be further reduced.
When the first switch tube Q1 is set to be a PNP triode and the second switch tube Q2 is set to be an NPN triode, the base of the first switch tube Q1 is used for receiving a target input voltage of a target topology circuit, the emitter of the first switch tube Q1 is connected with the first input end of the optocoupler PC, the second input end of the optocoupler PC is connected with the first end of the first resistor R1, the first output end of the optocoupler PC is connected with the emitter of the second switch tube Q2, the second output end of the optocoupler PC is connected with the third resistor R3, and the second resistor R2 and the third resistor R3 are connected with the CURRENT pin of the power management chip U together. The second end of the first resistor R1 is connected with a VREF pin of the power management chip U and used for outputting a reference voltage. The fourth resistor R4 and the first capacitor C1 form an oscillation circuit which is used for enabling an RC/CT pin of the power management chip U to generate sawtooth waves, and the second switch tube Q2 and the second resistor R2 jointly form a slope compensation circuit with fixed strength.
In this embodiment, can set up the opto-coupler PC as linear opto-coupler, because the current transmission characteristic curve of linear opto-coupler is close to the straight line, can carry out isolation control with linear characteristic, if use nonlinear opto-coupler, probably can make the oscillation waveform go bad, the phenomenon of unusual oscillation appears, so, in this embodiment, need set up opto-coupler PC as linear opto-coupler.
Referring to fig. 3, fig. 3 is a structural diagram of another slope compensation circuit according to an embodiment of the invention. In this embodiment, in order to filter the sampling CURRENT of the CURRENT pin of the power management chip U, a second capacitor C2 may be further disposed in the slope compensation circuit, wherein a first end of the second capacitor C2 is connected to a second end of the second resistor R2, and a second end of the second capacitor C2 is grounded.
In addition, in order to further simplify the circuit structure of the slope compensation circuit, two resistors can be directly used for building a voltage detection module. That is, the voltage detection module 11 is built by using the fifth resistor R5 and the sixth resistor R6; the second end of the fifth resistor R5 is connected with the first end of the sixth resistor R6 and the control end of the first switch tube Q1 respectively; correspondingly, a first end of the fifth resistor R5 is used for receiving an input signal of the target topology circuit, and a second end of the sixth resistor R6 is grounded.
As a preferred embodiment, the slope compensation circuit further includes: a seventh resistor R7;
the first end of the seventh resistor R7 is connected to the CURRENT end of the power management chip U.
It is understood that the CURRENT port of the power management chip U can feed back the instantaneous CURRENT output by the power management chip U. In this embodiment, in order to enable the instantaneous CURRENT in the power management chip U to be fed back to the circuit connected to the rear end of the power management chip U more gradually, a seventh resistor R7 may be connected to the CURRENT end of the power management chip U to limit the instantaneous CURRENT output by the power management chip U.
Referring to fig. 3, in fig. 3, the BUCK circuit is connected to the rear end of the power management chip U. And the CURRENT of the BUCK circuit feeds back the CURRENT inside the BUCK circuit to the CURRENT end of the power management chip U through a CS port in the BCUK circuit, and meanwhile, the OUT end of the power management chip U is connected with the control end of a switch tube VT in the BUCK circuit through an isolation module. The operation of the slope compensation circuit shown in fig. 3 will now be described in detail. After the BUCK circuit receives power supply, the proportional voltage division circuit formed by the fifth resistor R5 and the sixth resistor R6 enables the voltage at the two ends of the sixth resistor R6 to be in the amplification region of the first switch tube Q1. When the input voltage of the BUCK circuit rises, the slope compensation intensity required by the BUCK circuit is reduced, and the slope compensation CURRENT required by the CURRENT end of the power management chip U is reduced. Then the working principle of the slope compensation circuit at this time is: the input voltage of the BUCK circuit is increased → the voltage at two ends of the sixth resistor R6 is increased → the base CURRENT of the first switch tube Q1 is reduced → the CURRENT of the collector of the first switch tube Q1 is reduced → the CURRENT of the primary side of the optical coupler PC is reduced → the CURRENT of the secondary side of the optical coupler PC is reduced → the CURRENT flowing from the third resistor R3 to the CURRENT end of the power management chip U is reduced, so that the working mechanism that the higher the input voltage of the BCUK circuit is, the weaker the slope compensation intensity of the slope compensation circuit is realized.
When the input voltage of the BUCK circuit is reduced, the slope compensation intensity required by the BCUK circuit is increased, and the slope compensation CURRENT required by the CURRENT end of the power management chip U is increased. Then the working principle of the slope compensation circuit at this time is: the input voltage of the BUCK circuit is reduced → the voltage at two ends of the sixth resistor R6 is reduced → the base CURRENT of the first switch tube Q1 is increased → the CURRENT of the collector of the first switch tube Q1 is increased → the CURRENT of the primary side of the optical coupler PC is increased → the CURRENT of the secondary side of the optical coupler PC is increased → the CURRENT flowing from the third resistor R3 to the CURRENT management chip U is increased, so that the working mechanism that the lower the input voltage of the BUCK circuit is, the stronger the slope compensation intensity of the slope compensation circuit is realized.
Referring to fig. 4, fig. 4 is a schematic diagram illustrating a slope compensation of the BUCK circuit by using the slope compensation circuit shown in fig. 3. In fig. 4, the abscissa represents time t and the ordinate represents voltage V. Curve 1 represents the input voltage variation curve of the BUCK circuit; a curve 2 represents a change curve of the slope compensation intensity output by the slope compensation circuit with fixed intensity to the BUCK circuit, wherein the slope compensation circuit consists of a second switch tube Q2 and a second resistor R2; a curve 3 represents a change curve of the slope compensation intensity output by the adaptive adjustment intensity slope compensation circuit to the BUCK circuit, wherein the change curve is composed of a first switch tube Q1, a second switch tube Q2, an optocoupler PC, a first resistor R1, a third resistor R3, a fourth resistor R4, a first capacitor C1 and a second capacitor C2; the curve 4 represents a change curve of the slope compensation intensity output by the combined slope compensation circuit to the BUCK circuit, which is formed by combining the first switch tube Q1, the second switch tube Q2, the optocoupler PC, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the first capacitor C1 and the second capacitor C2. As can be seen from fig. 4, the strength of the slope compensation signal provided to the BUCK circuit can be adaptively adjusted by the slope compensation circuit provided in the present application.
Obviously, by the technical scheme provided by the embodiment, the slope compensation circuit can be applied to the whole input voltage range of the BUCK circuit on the premise of not influencing the working performance of the BUCK circuit.
Correspondingly, the embodiment of the invention also discloses a PWM modulation circuit, which comprises the slope compensation circuit disclosed in the foregoing.
The PWM (Pulse Width Modulation) Modulation circuit provided in the embodiment of the present invention has the beneficial effects of the slope compensation circuit disclosed above.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The slope compensation circuit and the PWM modulation circuit provided by the present invention are described in detail above, and the principle and the implementation of the present invention are explained in this document by applying specific examples, and the description of the above embodiments is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims (10)

1. A slope compensation circuit, comprising:
the voltage detection module is used for detecting the input voltage of the target topology circuit to obtain a target input voltage; wherein the target topology circuit is a circuit with subharmonic oscillation;
and the slope compensation module is used for outputting a slope compensation signal and adaptively adjusting the strength of the slope compensation signal so as to enable the strength of the slope compensation signal to form a negative correlation with the target input voltage and eliminate subharmonic oscillation of the target topological circuit.
2. The slope compensation circuit according to claim 1, wherein the slope compensation module is a compensation circuit constructed by a transistor, an optical coupler, an operational amplifier or a controllable precision voltage regulator.
3. The slope compensation circuit of claim 2, wherein the slope compensation module comprises: the circuit comprises a first switch tube, a second switch tube, an optocoupler, a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor and a power management chip;
the first end of the first switch tube is connected with the first input end of the optical coupler, the second input end of the optical coupler is connected with the first end of the first resistor, the first output end of the optical coupler is respectively connected with the first end of the second resistor and the first end of the second switch tube, the second output end of the optical coupler is connected with the first end of the third resistor, the second end of the third resistor is respectively connected with the second end of the second resistor and the CURRENT terminal of the power management chip, the second end of the first resistor is connected with the second end of the second switch tube, the first end of the fourth resistor and the VREF terminal of the power management chip, the control end of the second switch tube is respectively connected with the second end of the fourth resistor, the first end of the first capacitor and the RC/CT terminal of the power management chip, the second end of the first capacitor is grounded, and the VFB terminal of the power management chip is grounded;
correspondingly, the control terminal of the first switching tube is configured to receive the target input voltage, the OUT terminal of the power management chip is the output terminal of the slope compensation module, the CURRENT terminal of the power management chip is configured to receive the slope compensation signal, and the CURRENT of the target topology circuit is fed back to the CURRENT terminal of the power management chip through the target port of the target topology circuit.
4. The slope compensation circuit according to claim 3, wherein the first switching tube is a PNP transistor, and the second switching tube is an NPN transistor;
correspondingly, the base of the PNP triode is the control end of the first switch tube, the emitter of the PNP triode is the first end of the first switch tube, the collector of the PNP triode is the second end of the first switch tube, the base of the NPN triode is the control end of the second switch tube, the collector of the NPN triode is the first end of the second switch tube, and the emitter of the NPN triode is the second end of the second switch tube.
5. The slope compensation circuit of claim 3, further comprising: a second capacitor;
and the first end of the second capacitor is connected with the second end of the second resistor, and the second end of the second capacitor is grounded.
6. The slope compensation circuit of claim 3, wherein the voltage detection module comprises: a fifth resistor and a sixth resistor;
the second end of the fifth resistor is respectively connected with the first end of the sixth resistor and the control end of the first switching tube;
correspondingly, the first end of the fifth resistor is used for receiving the input signal of the target topology circuit, and the second end of the sixth resistor is grounded.
7. The slope compensation circuit of claim 3, further comprising: a seventh resistor;
the first end of the seventh resistor is connected with the CURRENT end of the power management chip.
8. The slope compensation circuit of claim 3, wherein the optocoupler is specifically a linear optocoupler.
9. The slope compensation circuit according to any one of claims 1 to 8, wherein the target topology circuit is in particular a BUCK circuit, a flyback circuit or a forward circuit.
10. A PWM modulation circuit comprising a slope compensation circuit according to any one of claims 1 to 9.
CN202211213340.3A 2022-09-30 2022-09-30 Slope compensation circuit and PWM modulation circuit Pending CN115395775A (en)

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CN202211213340.3A CN115395775A (en) 2022-09-30 2022-09-30 Slope compensation circuit and PWM modulation circuit

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Application Number Priority Date Filing Date Title
CN202211213340.3A CN115395775A (en) 2022-09-30 2022-09-30 Slope compensation circuit and PWM modulation circuit

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101212184A (en) * 2007-12-21 2008-07-02 康舒科技股份有限公司 Slope compensation method and circuit for power switching circuit
US20110018507A1 (en) * 2009-07-22 2011-01-27 Mccloy-Stevens Mark Switched power regulator
CN102323841A (en) * 2011-05-06 2012-01-18 杭州矽力杰半导体技术有限公司 Current hysteresis control circuit, current hysteresis control method and direct current-direct current converter applying both of same
CN102938611A (en) * 2011-08-15 2013-02-20 美国亚德诺半导体公司 Slope compensation voltage generation circuit and method, switch regulator and power source
JP2017099156A (en) * 2015-11-25 2017-06-01 株式会社デンソー Current mode control switching power supply device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101212184A (en) * 2007-12-21 2008-07-02 康舒科技股份有限公司 Slope compensation method and circuit for power switching circuit
US20110018507A1 (en) * 2009-07-22 2011-01-27 Mccloy-Stevens Mark Switched power regulator
CN102323841A (en) * 2011-05-06 2012-01-18 杭州矽力杰半导体技术有限公司 Current hysteresis control circuit, current hysteresis control method and direct current-direct current converter applying both of same
CN102938611A (en) * 2011-08-15 2013-02-20 美国亚德诺半导体公司 Slope compensation voltage generation circuit and method, switch regulator and power source
JP2017099156A (en) * 2015-11-25 2017-06-01 株式会社デンソー Current mode control switching power supply device

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