CN114337190A - An output voltage compensation circuit and compensation method - Google Patents

Abstract

The embodiment of the invention discloses an output voltage compensation circuit and a compensation method, wherein the circuit comprises: the device comprises a control module, a PWM output module, a power conversion module, a current detection module, a voltage compensation regulation module and a feedback module; the power conversion module is used for converting a signal at a voltage input end according to the PWM signal output by the PWM output module and then outputting the converted signal from the voltage output end; the current detection module is used for detecting the current flowing through the power conversion module, and the voltage compensation adjustment module is used for outputting compensation voltage to the feedback module according to the current detected by the current detection module and the voltage output by the power conversion module; the control module is used for adjusting the PWM signal output by the PWM output module according to the compensation voltage output by the voltage compensation adjustment module so as to adjust the output voltage of the power conversion module. The voltage drop generated by the wiring impedance can be compensated without remote feedback and increase of a feedback line, and the wiring complexity and cost are further reduced.

Description

An output voltage compensation circuit and compensation method

technical field

Embodiments of the present invention relate to the field of electronic technology, and in particular, to an output voltage compensation circuit and a compensation method.

Background technique

In the process of outputting current of the switching power supply, due to the equivalent resistance of the printed circuit board (Printed Circuit Board, PCB) trace, the voltage drop of the power supply will be caused when the current is transmitted from the output end of the power supply to the load end. The voltage drop is compensated by means of feedback.

At present, there are three main ways of switching power supply feedback, near-end feedback, far-end single-end feedback and far-end differential feedback. Proximal feedback is used to power power insensitive units, and far end feedback is used to power power sensitive units (eg, a central processing unit). The function of the remote feedback is that the switching power supply compensates the voltage drop caused by the PCB trace by collecting the voltage with the voltage drop at the load end as feedback. Ground trace voltage drop. However, in order to make the power supply more accurate, the remote feedback line needs to be connected from the load chip (chip out of the ball), and for complex multi-power supply systems (such as smart terminals such as mobile phones), it will increase the wiring cost and wiring complexity. .

SUMMARY OF THE INVENTION

The invention provides an output voltage compensation circuit and a compensation method, so as to realize the compensation of the voltage drop caused by the impedance of the wiring without remote feedback and without adding a feedback line, thereby reducing the complexity of the wiring and the manufacturing cost.

In a first aspect, an embodiment of the present invention provides an output voltage compensation circuit, the output voltage compensation circuit includes: a control module, a PWM output module, a power conversion module, a current detection module, a voltage compensation adjustment module, and a feedback module;

The control module is electrically connected to the PWM output module, the PWM output module is electrically connected to the power conversion module, and the PWM output module is used to output a PWM signal to the power conversion module, and the power conversion module The module is used to convert the signal of the voltage input terminal according to the PWM signal output by the PWM output module and output it from the voltage output terminal;

The current detection module is respectively electrically connected to the power conversion module and the voltage compensation adjustment module, the voltage compensation adjustment module is respectively electrically connected to the voltage output end of the power conversion module and the feedback module, the feedback The modules are respectively electrically connected with the current detection module and the control module; wherein, the current detection module is used for detecting the current flowing through the power conversion module, and the voltage compensation adjustment module is used for detecting the current according to the current detection module The detected current and the voltage output by the power conversion module output a compensation voltage to the feedback module;

Wherein, the control module is configured to adjust the PWM signal output by the PWM output module according to the compensation voltage output by the voltage compensation adjustment module to adjust the output voltage of the power conversion module.

In a second aspect, an embodiment of the present invention further provides a compensation method for an output voltage compensation circuit, characterized in that it is performed by an output voltage compensation circuit, and the output voltage compensation circuit includes a control module, a PWM output module, a power conversion module, a current A detection module, a voltage compensation adjustment module and a feedback module; wherein the control module is electrically connected to the PWM output module, the PWM output module is electrically connected to the power conversion module, and the PWM output module is used to output a PWM signal To the power conversion module, the power conversion module is used to convert the signal of the voltage input terminal and output it from the voltage output terminal according to the PWM signal output by the PWM output module; the current detection module is respectively connected with the power conversion module and the power conversion module. The voltage compensation adjustment module is electrically connected, and the voltage compensation adjustment module is respectively electrically connected with the voltage output end of the power conversion module and the feedback module, and the feedback module is respectively connected with the current detection module and the control module Electrical connection; wherein, the current detection module is used to detect the current flowing through the power conversion module, and the voltage compensation adjustment module is used to output according to the current detected by the current detection module and the voltage output by the power conversion module compensating the voltage to the feedback module;

The compensation method includes: adjusting the PWM signal output by the PWM output module according to the compensation voltage output by the voltage compensation adjustment module to adjust the output voltage of the power conversion module.

The invention provides an output voltage compensation circuit, which comprises: a control module, a PWM output module, a power conversion module, a current detection module, a voltage compensation adjustment module and a feedback module; wherein, the control module is electrically connected with the PWM output module, and the PWM output module is electrically connected to the PWM output module. The output module is electrically connected with the power conversion module, the PWM output module is used for outputting a PWM signal to the power conversion module, and the power conversion module is used for converting the signal of the voltage input terminal according to the PWM signal output by the PWM output module and outputting it from the voltage output terminal; current detection The modules are electrically connected to the power conversion module and the voltage compensation adjustment module respectively, the voltage compensation adjustment module is respectively electrically connected to the voltage output end of the power conversion module and the feedback module, and the feedback module is electrically connected to the current detection module and the control module respectively; The module is used to detect the current flowing through the power conversion module, and the voltage compensation adjustment module is used to output the compensation voltage to the feedback module according to the current detected by the current detection module and the voltage output by the power conversion module; wherein, the control module is used to compensate the adjustment module according to the voltage The output compensation voltage adjusts the PWM signal output by the PWM output module to adjust the output voltage of the power conversion module. It can be seen that the circuit can solve the problems of high wiring complexity and high wiring manufacturing cost in the existing compensation method, and can compensate the voltage drop caused by the wiring impedance without remote feedback and without adding feedback lines. , thereby reducing the wiring complexity and manufacturing cost.

Description of drawings

1 is a schematic structural diagram of an output voltage compensation circuit in Embodiment 1 of the present invention;

2 is a schematic structural diagram of an output voltage compensation circuit in Embodiment 2 of the present invention;

3 is a schematic structural diagram of an output voltage compensation circuit in Embodiment 3 of the present invention;

FIG. 4 is a flowchart of a compensation method for an output voltage compensation circuit in Embodiment 4 of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all structures related to the present invention.

Example 1

1 is a schematic structural diagram of an output voltage compensation circuit provided in Embodiment 1 of the present invention. Referring to FIG. 1 , the output voltage compensation circuit includes: a control module 10 , a PWM output module 20 , a power conversion module 30 , and a current detection module 40 , a voltage compensation adjustment module 50 and a feedback module 60;

The control module 10 is electrically connected to the PWM output module 20, the PWM output module 20 is electrically connected to the power conversion module 30, the PWM output module 20 is used for outputting PWM signals to the power conversion module 30, and the power conversion module 30 is used for outputting the module according to the PWM The PWM signal output by 20 converts the signal at the voltage input terminal and outputs it from the voltage output terminal;

The current detection module 40 is electrically connected to the power conversion module 30 and the voltage compensation adjustment module 50 respectively, the voltage compensation adjustment module 50 is respectively electrically connected to the voltage output end of the power conversion module 30 and the feedback module 60 , and the feedback module 60 is respectively connected to the current detection module 40 is electrically connected to the control module 10; wherein, the current detection module 40 is used to detect the current flowing through the power conversion module 30, and the voltage compensation adjustment module 50 is used to output compensation according to the current detected by the current detection module 40 and the voltage output by the power conversion module 30 voltage to the feedback module 60;

The control module 10 is configured to adjust the PWM signal output by the PWM output module 20 according to the compensation voltage output by the voltage compensation adjustment module 50 to adjust the output voltage of the power conversion module 30 .

The control module 10 may be a control chip with a trigger function. The current detection module 40 may be a current source detection chip.

In the technical solution of this embodiment, the implementation process of the output voltage compensation circuit is: referring to FIG. 1 , the control module 10 controls the PWM output module 20 to output a PWM signal to the power conversion module 30 , and controls the output of the power conversion module 30 through the PWM signal . Since the power supply wiring has a certain equivalent impedance, the voltage output by the power conversion module 30 will generate a certain voltage drop through the power supply wiring, so that the voltage requirement of the load terminal cannot be guaranteed. Therefore, in this embodiment of the present invention, the current flowing through the power conversion module 30 is detected by the current detection module 40 , and the detected current is output to the voltage compensation adjustment module 50 , and the output compensation voltage is adjusted by the voltage compensation adjustment module 50 to the feedback module 60 , and then It is output from the feedback module 60 to the control module 10 , and the control module 10 controls the PWM output module 20 to output the PWM signal according to the compensation voltage fed back by the feedback module 60 to adjust the output voltage of the power conversion module 30 . Therefore, by feeding back the compensation voltage output by the voltage compensation adjustment module 50 to the control module 10, the control module 10 adjusts the PWM signal output by the PWM output module 20 according to the compensation voltage to adjust the voltage output of the power conversion module 30, thereby compensating for the power conversion The voltage output by the module 30 is due to the voltage drop caused by the impedance of the power traces. Therefore, the problems of high wiring complexity and high wiring manufacturing cost in the existing compensation method can be solved by the embodiments of the present invention, and the voltage drop caused by the wiring impedance can be compensated without remote feedback and without adding a feedback line. , thereby reducing the wiring complexity and manufacturing cost.

The embodiment of the present invention provides an output voltage compensation circuit, the circuit includes: a control module, a PWM output module, a power conversion module, a current detection module, a voltage compensation adjustment module and a feedback module; wherein, the control module is electrically connected to the PWM output module , the PWM output module is electrically connected with the power conversion module, the PWM output module is used to output the PWM signal to the power conversion module, and the power conversion module is used to convert the signal of the voltage input terminal according to the PWM signal output by the PWM output module and output from the voltage output terminal; The current detection module is respectively electrically connected with the power conversion module and the voltage compensation adjustment module, the voltage compensation adjustment module is respectively electrically connected with the voltage output end of the power conversion module and the feedback module, and the feedback module is electrically connected with the current detection module and the control module respectively; wherein, The current detection module is used for detecting the current flowing through the power conversion module, and the voltage compensation adjustment module is used for outputting the compensation voltage to the feedback module according to the current detected by the current detection module and the voltage output by the power conversion module; wherein, the control module is used for compensation according to the voltage The compensation voltage output by the adjustment module adjusts the PWM signal output by the PWM output module to adjust the output voltage of the power conversion module. It can be seen that the circuit can solve the problems of high wiring complexity and high wiring manufacturing cost in the existing compensation method, and can compensate the voltage drop caused by the wiring impedance without remote feedback and without adding feedback lines. , thereby reducing the wiring complexity and manufacturing cost.

Embodiment 2

2 is a schematic structural diagram of an output voltage compensation circuit provided in Embodiment 2 of the present invention. On the basis of Embodiment 1 above, referring to FIG. 2 , the power conversion module 30 includes a first transistor M1, a second transistor M2, a The three transistors M3 and the first inductor L1, the control terminal of the first transistor M1 and the control terminal of the second transistor M2 are both electrically connected to the first output terminal of the PWM output module 20, and the control terminal of the third transistor M3 is electrically connected to the PWM output module 20 The second output terminal of the first transistor M1 and the first terminal of the second transistor M2 are both electrically connected to the voltage input terminal Vin, and the second terminal of the first transistor M1 is electrically connected to the first terminal of the third transistor M3. The terminals are electrically connected, the second terminal of the third transistor M3 is grounded, the second terminal of the second transistor M2 is electrically connected to the second terminal of the first transistor M1 and the first terminal of the first inductor L1 respectively, and the first terminal of the first inductor L1 The two terminals are electrically connected to the voltage output terminal Vout;

The first end of the second transistor M2 is also electrically connected to the current detection module 40, and the current detection module 40 is used for detecting the current flowing into the second transistor M2 from the voltage input terminal Vin.

2 , the control module 10 can control the turn-on or turn-off of the first transistor M1 , the second transistor M2 and the third transistor M3 by controlling the PWM output module 20 to output a PWM signal, thereby controlling the voltage input at the voltage input terminal Vin The voltage is output from the voltage output terminal Vout. The first transistor M1 and the second transistor M2 may be PMOS transistors, and the third transistor M3 may be an NMOS transistor.

Wherein, referring to FIG. 2 , the power conversion module 30 further includes an impedance element R3. The voltage input terminal Vin further includes a first capacitive element C1, and the voltage output terminal Vout further includes a second capacitive element C2. The first end of the first capacitive element C1 is electrically connected to the voltage input end Vin, and the second end is grounded. The first end of the second capacitive element C2 is electrically connected to the voltage output end Vout, and the second end is grounded. The first capacitive element C1 and the second capacitive element C2 are used for filtering.

Optionally, continuing to refer to FIG. 2 , the voltage compensation adjustment module 50 includes a proportional control unit 51 , an adder 52 and an output voltage adjustment unit 53 . The proportional control unit 51 is electrically connected to the first input terminals of the current detection module 40 and the adder 52 respectively. connected, the output voltage adjustment unit 53 is respectively electrically connected to the voltage output terminal Vout of the power conversion module 30 and the second input terminal of the adder 52, and the output terminal of the adder 52 is electrically connected to the feedback module 60;

The proportional control unit 51 is used to amplify the current detected by the current detection module 40 according to the preset proportional amplification factor and output it to the first input end of the adder 52, and the output voltage adjustment unit 53 is used to convert the power The voltage output by the voltage output terminal Vout of the module 30 is adjusted by the resistor and then output to the second input terminal of the adder 52. The adder 52 is used to superimpose the voltages input from the first input terminal and the second input terminal and output to the feedback module 60.

The voltage output by the superposition of the voltages input from the first input terminal and the second input terminal of the adder 52 is the compensation voltage, and the compensation voltage is output to the second input terminal of the feedback module 60 , and is combined with the voltage input from the first input terminal of the feedback module 60 . The reference voltage signal Vref is compared and output to the control module 10, and the control module 10 controls the PWM output module 20 to output a PWM signal according to the feedback compensation voltage to adjust the output voltage of the power conversion module 30, thereby compensating for the voltage drop caused by the impedance of the power supply wiring .

The proportional control unit 51 may be a proportional amplifier. The voltage output by the power conversion module 30 can be compensated by adjusting the preset proportional amplification factor of the proportional amplifier. The voltage of the voltage output terminal Vout of the power conversion module 30 can be adjusted by adjusting the output voltage adjusting unit 53 . Optionally, the preset proportional amplification factor of the proportional control unit 51 may be configured by a separate digital control module (eg, a single-chip microcomputer). The output voltage adjustment unit can also be adjusted by the digital control module to adjust the output voltage of the voltage output terminal Vout of the power conversion module 30 .

Optionally, continuing to refer to FIG. 2 , the output voltage adjusting unit 53 includes a first resistor R1 and a second resistor R2, the first end of the first resistor R1 is electrically connected to the voltage output end Vout, and the second end of the first resistor R1 is respectively It is electrically connected to the second input terminal of the adder 52 and the first terminal of the second resistor R2, and the second terminal of the second resistor R2 is grounded.

The voltage output by the first resistor R1 is output to the second input terminal of the adder 52 , and the voltage output by the proportional control unit 51 is output to the first input terminal of the adder 52 . The voltage output by the adder 52 after superimposing the voltages input from the first input terminal and the second input terminal is the compensated feedback voltage, and the compensated feedback voltage is output to the control module 10 through the feedback module 60, and the control module 10 according to this The feedback voltage after compensation controls the PWM output module 20 to output a PWM signal to adjust the output voltage of the power conversion module 30 , thereby compensating for the voltage drop caused by the impedance of the power supply wiring.

Optionally, the first resistor R1 is a variable resistor.

The resistance value of the first resistor can be configured by a separate digital control module (eg, a single-chip microcomputer) to adjust the voltage of the voltage output terminal Vout of the power conversion module 30 . In addition, the first resistor R1 can also be a sliding varistor.

Optionally, with continued reference to FIG. 2 , the voltage compensation adjustment module 50 further includes a filter unit 54 , and the filter unit 54 is electrically connected to the current detection module 40 and the proportional control unit 51 , respectively.

The filtering unit 54 may be a low-pass filter.

Optionally, continuing to refer to FIG. 2 , the feedback module 60 includes an operational amplifier B1 and a comparator B2, the first input terminal of the operational amplifier B1 is connected to the reference voltage signal Vref, and the second input terminal of the operational amplifier B1 is connected to the voltage compensation adjustment module 50. Electrically connected, the output terminal of the operational amplifier B1 is electrically connected to the first input terminal of the comparator B2, the second input terminal of the comparator B2 is electrically connected to the current detection module 40, and the output terminal of the comparator B2 is electrically connected to the control module 10.

The operational amplifier B1 may be an error amplifier, which is used to amplify the error between the compensation voltage output by the output end of the adder 52 and the reference voltage signal Vref. Among them, the reference voltage signal Vref is a bandgap reference source. The comparator B2 is used for outputting the compensated feedback voltage output by the amplifier operational amplifier B1 to the feedback terminal R of the control module 10 . In addition, the feedback module 60 also includes a ramp compensation module Vramp, and the ramp compensation module Vramp is used to superimpose the current signal output by the current detection module 40 and the ramp signal output by the ramp compensation module Vramp and output to the positive pole of the operational amplifier, thereby , the stability of the current signal can be improved by the superposition compensation of the signal.

In the technical solution of this embodiment, the working principle of the voltage compensation adjustment module 50 and the feedback module 60 is as follows: with reference to FIG. 2 , it is assumed that the average current input by the voltage input terminal Vin of the power conversion module 30 is Iin, and the voltage output terminal Vout outputs the average current of Iin. If the voltage is Vo, the average output current is Io, the impedance of the PCB trace loop is R0, and the impedance of the power trace loop inside the load chip is R1, the power supply voltage drop that needs to be compensated is Io*(R0+R1).

Since the current output by the current detection module 40 is proportional to the average current Iin input by the voltage input terminal Vin, and the proportional coefficient is set to be a, the voltage V1 output by the filter unit 54 is:

V1=a*Iin

Assuming that the efficiency of the power supply is η, where the efficiency η can be obtained by testing, in the case where the input and output are determined, η is related to the load, and usually takes the maximum value, then the average output current Io can be calculated as:

The voltage V2 output by the proportional control unit 51 is:

V2=-Io*(R0+R1)*Vref/Vo

Wherein, Vref is the reference voltage input by the first input terminal of the operational amplifier B1.

Therefore, according to the above two formulas V1 and V2, the proportional amplification coefficient P of the proportional control unit 51 can be obtained as:

Among them, R1, η, Vref, a are determined by the chip itself and are fixed parameters of the chip. R0, Vo and Vin are determined by specific products and can be adjusted according to actual usage. Among them, in order to ensure the stability of the system, a can take the minimum value under the chip technology, the efficiency η of the power supply can take the maximum value under all loads, and the impedance of the PCB trace loop is the difference between R0 and the power trace loop inside the load chip. The impedance R1 can be obtained by simulation technology, and Vo can be adjusted by adjusting the output voltage adjusting unit 53 .

Therefore, in the process of compensating and adjusting the output voltage compensation circuit, the output voltage of the output voltage adjusting unit 53 can be adjusted by a separate digital control module (such as a single-chip microcomputer) to adjust the voltage of the voltage output terminal Vout of the power conversion module 30, The impedance R0 of the PCB trace loop and the impedance R1 of the power trace loop inside the load chip are obtained through simulation technology. According to the voltage of the voltage output terminal Vout, the impedance R0 of the PCB trace loop and the impedance of the power trace loop inside the load chip Parameters such as R1 can configure the preset proportional amplification factor of the proportional control unit 51, so that the proportional control unit outputs the voltage value that needs to be compensated by the power conversion module 30, and feeds back the voltage value to be compensated to the control unit through the adder 52 and the feedback module 60. At the feedback terminal R of the module 10 , the control module 10 controls the PWM output module 20 to output the PWM signal according to the feedback signal to adjust the output voltage of the power conversion module 30 .

Optionally, an overcurrent protection module 70 is further included, and the overcurrent protection module 70 is electrically connected to the current detection module 40 and the control module 10 respectively.

The overcurrent protection module 70 is electrically connected to the power conversion module 30 for inputting the detected current of the power conversion module 30 to the overcurrent protection feedback terminal of the control module 10 to detect whether the power conversion module 30 is overcurrent.

In addition, referring to FIG. 2 , the output voltage compensation circuit further includes an overvoltage protection module OVP, a frequency configuration module PFM and a signal source S. The overvoltage protection module OVP is used to protect the circuit when overvoltage occurs, and the frequency configuration module PFM can configure the frequency of the control module 10, and the provided frequency is used when the power supply is lightly loaded.

Embodiment 3

FIG. 3 is a schematic structural diagram of an output voltage compensation circuit provided in Embodiment 3 of the present invention. On the basis of the above embodiment, referring to FIG. 3 , the power conversion module 30 includes a fourth transistor M4, a fifth transistor M5 and a second transistor M4. Inductor L2, the control terminal of the fourth transistor M4 is electrically connected to the first output terminal of the PWM output module 20, the first terminal of the fourth transistor M4 is electrically connected to the voltage input terminal Vin, and the second terminal of the fourth transistor M4 is respectively connected to the first output terminal of the PWM output module 20. The first terminal of the fifth transistor M5 is electrically connected to the first terminal of the second inductor L2, the control terminal of the fifth transistor M5 is electrically connected to the second output terminal of the PWM output module 20, the second terminal of the fifth transistor M5 is grounded, and the first terminal of the fifth transistor M5 is electrically connected to the second output terminal of the PWM output module 20. The second terminal of the two inductors L2 is electrically connected to the voltage output terminal Vout;

The first end and the second end of the second inductor L2 are respectively electrically connected to the current detection module 40, and the current detection module 40 is used for detecting the current flowing into the second inductor L2.

The control module 10 can control the fourth transistor M4 and the fifth transistor M5 to be turned on or off by controlling the PWM output module 20 to output a PWM signal, thereby controlling the voltage input from the voltage input terminal Vin to be output from the voltage output terminal Vout. The fourth transistor M4 may be a P-type MOS transistor, and the fifth transistor M5 may be an N-type MOS transistor.

In the technical solution of the present embodiment, the working principle of the voltage compensation adjustment module 50 and the feedback module 60 is as follows: with reference to FIG. 2 , assuming that the voltage output by the voltage output terminal Vout of the power conversion module 30 is Vo and the average output current is Io, the first The resistance of an inductor L1 is RL, the impedance of the PCB trace loop is R0, and the impedance of the power trace loop inside the load chip is R1, so the power supply voltage drop that needs to be compensated is Io*(R0+R1).

Since the current output by the current detection module 40 is proportional to the average current of the voltage output terminal as Io, and the proportional coefficient is set as a, the voltage V1 output by the filter unit 54 is:

V1=a*Io*RL

The voltage V2 output by the proportional control unit 51 is:

V2=-Io*(R0+R1)*Vref/Vo

Wherein, Vref is the reference voltage input by the first input terminal of the operational amplifier B1.

Therefore, according to the above two formulas V1 and V2, the proportional amplification coefficient P of the proportional control unit 51 can be obtained as:

Among them, R1, Vref, a are determined by the chip itself and are fixed parameters of the chip. R0, Vo and RL are determined by specific products and can be adjusted according to actual usage. Among them, in order to ensure the stability of the system, a can take the minimum value under the chip technology, RL can take the minimum value of the first inductance, the impedance of the PCB trace loop is R0 and the impedance of the power trace loop inside the load chip is R1 can be obtained by simulation technology, and Vo can be adjusted by adjusting the output voltage adjusting unit 53 .

Therefore, in the process of compensating and adjusting the output voltage compensation circuit, the output voltage of the output voltage adjusting unit 53 can be adjusted by a separate digital control module (such as a single-chip microcomputer) to adjust the voltage of the voltage output terminal Vout of the power conversion module 30. The simulation technology obtains the impedance R0 of the PCB trace loop and the impedance R1 of the power trace loop inside the load chip. According to the voltage of the voltage output terminal Vout, the impedance R0 of the PCB trace loop and the impedance R1 of the power trace loop inside the load chip and other parameters can configure the preset proportional amplification factor of the proportional control unit 51, so that the proportional control unit outputs the voltage value that needs to be compensated by the power conversion module 30, and feeds back the voltage value to be compensated to the control module through the adder 52 and the feedback module 60 The feedback terminal R of 10 is controlled by the control module 10 according to the feedback signal to control the PWM output module 20 to output the PWM signal to adjust the output voltage of the power conversion module 30 .

Embodiment 4

4 is a flowchart of an output voltage compensation circuit compensation method provided in Embodiment 4 of the present invention, which is executed by the output voltage compensation circuit, and the output voltage compensation circuit includes a control module, a PWM output module, a power conversion module, a current detection module, Voltage compensation adjustment module and feedback module; wherein, the control module is electrically connected with the PWM output module, the PWM output module is electrically connected with the power conversion module, the PWM output module is used for outputting PWM signals to the power conversion module, and the power conversion module is used for outputting according to the PWM The PWM signal output by the module converts the signal of the voltage input terminal and outputs it from the voltage output terminal; the current detection module is electrically connected with the power conversion module and the voltage compensation adjustment module respectively, and the voltage compensation adjustment module is respectively connected with the voltage output terminal of the power conversion module and the feedback module. The feedback module is electrically connected to the current detection module and the control module respectively; wherein, the current detection module is used to detect the current flowing through the power conversion module, and the voltage compensation adjustment module is used to output the current detected by the current detection module and the power conversion module The voltage output compensation voltage to the feedback module;

This embodiment is applicable to the implementation process of the output voltage compensation circuit, and the method may be performed by the output voltage compensation circuit provided by any embodiment of the present invention. Referring to FIG. 4 , the method specifically includes the following steps:

Step 110: Adjust the PWM signal output by the PWM output module according to the compensation voltage output by the voltage compensation adjustment module to adjust the output voltage of the power conversion module.

In the technical solution of this implementation, the current flowing through the power conversion module is detected by the current detection module, the detected current is output to the voltage compensation adjustment module, the output compensation voltage is adjusted by the voltage compensation adjustment module to the feedback module, and then the feedback module It is output to the control module, and the control module controls the PWM output module to output the PWM signal according to the feedback signal of the feedback module to adjust the output voltage of the power conversion module. Therefore, by feeding back the compensation voltage output by the voltage compensation adjustment module to the control module, the control module adjusts the PWM signal output by the PWM output module according to the compensation voltage to adjust the voltage output of the power conversion module, thereby compensating the power conversion module due to the PCB wiring. , the voltage drop caused by the impedance of the internal power supply wiring of the load chip. Therefore, the embodiments of the present invention can solve the problems of high wiring complexity and high wiring manufacturing cost in the existing compensation method, and realize that the voltage drop caused by the wiring impedance can be compensated without remote feedback and adding feedback lines, This further reduces wiring complexity and manufacturing costs.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention. The scope is determined by the scope of the appended claims.

Claims (10)

1. An output voltage compensation circuit, comprising: the device comprises a control module, a PWM output module, a power conversion module, a current detection module, a voltage compensation regulation module and a feedback module;

the control module is electrically connected with the PWM output module, the PWM output module is electrically connected with the power conversion module, the PWM output module is used for outputting a PWM signal to the power conversion module, and the power conversion module is used for converting a signal at a voltage input end according to the PWM signal output by the PWM output module and then outputting the converted signal from a voltage output end;

the current detection module is respectively and electrically connected with the power conversion module and the voltage compensation adjustment module, the voltage compensation adjustment module is respectively and electrically connected with the voltage output end of the power conversion module and the feedback module, and the feedback module is respectively and electrically connected with the current detection module and the control module; the current detection module is used for detecting the current flowing through the power conversion module, and the voltage compensation adjustment module is used for outputting compensation voltage to the feedback module according to the current detected by the current detection module and the voltage output by the power conversion module;

the control module is used for adjusting the PWM signal output by the PWM output module according to the compensation voltage output by the voltage compensation adjusting module so as to adjust the output voltage of the power conversion module.

2. The output voltage compensation circuit of claim 1, wherein the power conversion module comprises a first transistor, a second transistor, a third transistor, and a first inductor, the control end of the first transistor and the control end of the second transistor are both electrically connected with the first output end of the PWM output module, a control terminal of the third transistor is electrically connected with the second output terminal of the PWM output module, a first terminal of the first transistor and a first terminal of the second transistor are both electrically connected to the voltage input terminal, a second terminal of the first transistor is electrically connected to a first terminal of the third transistor, a second terminal of the third transistor is grounded, a second end of the second transistor is electrically connected with a second end of the first transistor and a first end of the first inductor respectively, and a second end of the first inductor is electrically connected with the voltage output end;

the first end of the second transistor is electrically connected to the current detection module, and the current detection module is configured to detect a current flowing into the second transistor from the voltage input end.

3. The output voltage compensation circuit of claim 1, wherein the power conversion module comprises a fourth transistor, a fifth transistor and a second inductor, a control terminal of the fourth transistor is electrically connected to the first output terminal of the PWM output module, a first terminal of the fourth transistor is electrically connected to the voltage input terminal, a second terminal of the fourth transistor is electrically connected to the first terminal of the fifth transistor and the first terminal of the second inductor, respectively, a control terminal of the fifth transistor is electrically connected to the second output terminal of the PWM output module, a second terminal of the fifth transistor is grounded, and a second terminal of the second inductor is electrically connected to the voltage output terminal;

the first end and the second end of the second inductor are respectively electrically connected with the current detection module, and the current detection module is used for detecting current flowing into the second inductor.

4. The output voltage compensation circuit of claim 1, wherein the voltage compensation adjustment module comprises a proportional control unit, an adder and an output voltage adjustment unit, the proportional control unit is electrically connected to the current detection module and a first input terminal of the adder respectively, the output voltage adjustment unit is electrically connected to a voltage output terminal of the power conversion module and a second input terminal of the adder respectively, and an output terminal of the adder is electrically connected to the feedback module;

the proportional control unit is configured to adjust the current detected by the current detection module according to a preset proportional amplification factor and output the current to a first input end of the adder, the output voltage adjustment unit is configured to adjust the voltage output by the voltage output end of the power conversion module and output the voltage to a second input end of the adder, and the adder is configured to superimpose the voltages input by the first input end and the second input end of the adder and output the voltage to the feedback module.

5. The output voltage compensation circuit of claim 4, wherein the output voltage adjustment unit comprises a first resistor and a second resistor, a first end of the first resistor is electrically connected to the voltage output terminal, a second end of the first resistor is electrically connected to the second input terminal of the adder and the first end of the second resistor, respectively, and a second end of the second resistor is grounded.

6. The output voltage compensation circuit of claim 5, wherein the first resistor is a variable resistor.

7. The output voltage compensation circuit of claim 4, wherein the voltage compensation adjustment module further comprises a filtering unit electrically connected to the current detection module and the proportional control unit, respectively.

8. The output voltage compensation circuit of claim 1, wherein the feedback module comprises an operational amplifier and a comparator, a first input terminal of the operational amplifier is connected to a reference voltage signal, a second input terminal of the operational amplifier is electrically connected to the voltage compensation adjustment module, an output terminal of the operational amplifier is electrically connected to a first input terminal of the comparator, a second input terminal of the comparator is electrically connected to the current detection module, and an output terminal of the comparator is electrically connected to the control module.

9. The output voltage compensation circuit of claim 1, further comprising an over-current protection module electrically connected to the current detection module and the control module, respectively.

10. The output voltage compensation circuit compensation method is characterized by being executed by an output voltage compensation circuit, wherein the output voltage compensation circuit comprises a control module, a PWM output module, a power conversion module, a current detection module, a voltage compensation regulation module and a feedback module; the control module is electrically connected with the PWM output module, the PWM output module is electrically connected with the power conversion module, the PWM output module is used for outputting a PWM signal to the power conversion module, and the power conversion module is used for converting a signal at a voltage input end according to the PWM signal output by the PWM output module and then outputting the converted signal from a voltage output end; the current detection module is respectively and electrically connected with the power conversion module and the voltage compensation adjustment module, the voltage compensation adjustment module is respectively and electrically connected with the voltage output end of the power conversion module and the feedback module, and the feedback module is respectively and electrically connected with the current detection module and the control module; the current detection module is used for detecting the current flowing through the power conversion module, and the voltage compensation adjustment module is used for outputting compensation voltage to the feedback module according to the current detected by the current detection module and the voltage output by the power conversion module;

the compensation method comprises the following steps: and adjusting the output voltage of the power conversion module according to the compensation voltage output by the voltage compensation adjustment module and the PWM signal output by the PWM output module.

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