Circuit for improving PWM (Pulse Width Modulation) driving power

Abstract

The utility model discloses a circuit for improving PWM (Pulse Width Modulation) driving power. The control circuit comprises a control module, a voltage following module and a switch module, the control module is electrically connected with the voltage following module and the switch module respectively, the voltage following module is electrically connected with the switch module, and the switch module is electrically connected with the rectifying circuit and the load circuit. According to the characteristic of the voltage following module, that is, the output signal is equal to the input signal, the voltage following module can enable the input impedance to be high and the output impedance to be low, the high input impedance is equivalent to the open circuit of the input end circuit, and the low output impedance is equivalent to the output end capable of outputting constant power, so that the output signal can be output constantly; and the influence of circuit element loss and line impedance is avoided, so that the driving power of an output signal is improved. Therefore, the driving power of the PWM driving signal is not weakened, and the situation that the switch module cannot be normally driven due to insufficient driving power of the PWM driving signal is prevented.

Description

Technical Field

[0001] The utility model relates to the field of circuits, and in particular to a circuit for improving PWM drive power. Background Art

[0002] In the wiring layout of the PCB, the ground wire needs to be connected to each grounding point, so the area of ​​the ground wire will be relatively large. Due to the influence of the wiring layout of the PCB and the electronic components, the ground wire routing often needs to be set in a curved way to avoid the electronic components. However, due to the bending of the ground wire and the large area of ​​the ground wire routing set on the PCB, the ground wire routing is too long, and the ground wire resistance will increase due to the increase in the length of the ground wire, which will lead to a relatively large line resistance of the ground wire. The drive signal output by the MCU will be weakened during the transmission process due to the loss of the ground wire length and the ground wire resistance, especially the drive signal driven by PWM. The impact is particularly obvious. Therefore, the drive signal driven by PWM is weakened, resulting in insufficient power of the output drive signal, which cannot normally drive components such as MOS tubes. Utility Model Content

[0003] In view of the shortcomings of the prior art, the utility model provides a circuit for improving PWM drive power.

[0004] The purpose of the utility model is achieved through the following solutions:

[0005] A circuit for improving PWM drive power includes: a rectifier circuit, a control circuit and a load circuit, wherein the control circuit includes a control module, a voltage follower module and a switch module, wherein the control module is electrically connected to the voltage follower module and the switch module respectively, wherein the voltage follower module is electrically connected to the switch module, and wherein the switch module is electrically connected to the rectifier circuit and the load circuit.

[0006] In one embodiment, the control module includes a control chip and a driving power supply VCC, the control chip has terminals 1 to 8, the driving power supply VCC is electrically connected to terminal 7 of the control chip, the voltage follower module is electrically connected to terminal 8 of the control chip, and the switch module is electrically connected to terminal 2 of the control chip.

[0007] In one embodiment, the control module further includes a first filter module, and the first filter module is electrically connected to terminal 1 of the control chip and a ground GND.

[0008] In one embodiment, the control module further includes a first differential module, and the first differential module is electrically connected to terminal 6 of the control chip and a ground GND.

[0009] In one embodiment, the control module further includes a second filter module, and the second filter module is electrically connected to terminal 3 of the control chip and a ground GND.

[0010] In one embodiment, the control module further includes a second differential module, and the second differential module is electrically connected to terminal 5 of the control chip and a ground GND.

[0011] In one embodiment, the control module further includes a regulating module, and the regulating module is electrically connected to terminal 4 of the control chip and a ground GND.

[0012] In one embodiment, the voltage follower module includes an operational amplifier OP1 and a working power supply VIN, the operational amplifier OP1 has terminal 1, terminal 2, terminal 3 and terminal 4, terminal 1 of the operational amplifier OP1 is electrically connected to the switch module; terminal 2 of the operational amplifier OP1 is electrically connected to terminal 1; terminal 3 is electrically connected to the control module; and terminal 4 is electrically connected to the working power supply VIN.

[0013] In one embodiment, the switch module includes a MOS tube Q1, which has a drain D1, a gate G1 and a source S1, the drain D1 of the MOS tube Q1 is electrically connected to the rectifier circuit, the gate G1 of the MOS tube Q1 is electrically connected to the voltage follower module, and the source S1 of the MOS tube Q1 is electrically connected to the control module (21).

[0014] Compared with the prior art, the utility model has at least the following advantages:

[0015] The utility model provides a circuit for improving PWM driving power by setting a voltage follower module. According to the characteristics of the voltage follower module, that is, the output signal is equal to the input signal, the voltage follower module can make the input impedance high and the output impedance low. The high input impedance is equivalent to the input end circuit being open, and the very low output impedance is equivalent to the output end being able to output constant power, so that the output signal can be outputted constantly without being affected by the loss of circuit components and the impedance of the line, thereby improving the driving power of the output signal. As a result, the driving power of the PWM driving signal will not be weakened, preventing the switch module from being unable to be driven normally due to insufficient driving power of the PWM driving signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 This is a circuit structure diagram of the utility model;

[0018] Figure 2 for Figure 1 Circuit diagram of the control circuit;

[0019] Among them, the figure markings are, 10. Rectification module; 20. Control circuit; 21. Control module; 211. Control chip; 212. Driving power supply VCC; 213. First filter module; 214. First differential module; 215. Second filter module; 216. Second differential module 217. Adjustment module; 22. Voltage follower module; 23. Switch module; 30. Load circuit. DETAILED DESCRIPTION

[0020] The following will disclose multiple embodiments of the present invention with drawings. For the purpose of clear description, many practical details will be described together in the following description. However, it should be understood that these practical details should not be used to limit the present invention. In other words, in some embodiments of the present invention, these practical details are not necessary. In addition, in order to simplify the drawings, some conventional structures and components will be depicted in a simple schematic manner in the drawings.

[0021] It should be noted that all directional indications such as up, down, left, right, front, back... in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, in the present utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present utility model. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0023] In order to further understand the content, features and functions of the utility model, the following embodiments are given as examples and described in detail with the accompanying drawings: Check the connection and marking of components in accordance with the modification of the claims

[0024] like Figure 1As shown, a circuit for improving PWM drive power includes: a rectifier circuit 10, a control circuit 20 and a load circuit 30, the control circuit 20 includes a control module 21, a voltage follower module 22 and a switch module 23, the control module 21 is electrically connected to the voltage follower module 22 and the switch module 23 respectively, the voltage follower module 22 is electrically connected to the switch module 23, and the switch module 22 is electrically connected to the rectifier circuit 10 and the load circuit 30. When in use, the mains is connected, the mains is electrically connected to the rectifier circuit 10, the rectifier circuit 10 converts the alternating current of the mains into direct current, and provides power to the control circuit 20 and the load circuit 30, and the control circuit 20 is used to control the on and off of the load circuit 30.

[0025] Further, the control module 21 includes a control chip 211 and a driving power source VCC 212, the control chip 211 has terminals 1 to 8, the driving power source VCC 212 is electrically connected to terminal 7 of the control chip 211, the voltage follower module 222 is electrically connected to terminal 8 of the control chip 211, and the switch module 23 is electrically connected to terminal 2 of the control chip 211. The control chip 211 controls the voltage follower module 22 and the switch module 23, and the driving power source VCC 212 is used to provide power to the control chip 211. In this embodiment, the control chip 211 adopts ICE3PCS03GXUMA1.

[0026] Specifically, the control module 21 further includes a first filter module 213, which is electrically connected to terminal 1 of the control chip 211 and the ground GND. The first filter module 213 includes a capacitor C1, which has a terminal 1 and a terminal 2, the terminal 1 of the capacitor C1 is electrically connected to the terminal 1 of the control chip 211, and the terminal 2 of the capacitor C1 is electrically connected to the ground GND. It should be noted that the capacitor C1 can be used for filtering to eliminate noise interference with the control chip 211.

[0027] Specifically, the control module 21 also includes a first differential module 214, and the first differential module 214 is electrically connected to the terminal 6 of the control chip 211 and the ground GND. The first differential module 214 includes a resistor R3, a resistor R4 and a capacitor C5, and the resistor R3, the resistor R4 and the capacitor C5 have a terminal 1 and a terminal 2 respectively, and the terminal 1 of the resistor R3, the resistor R4 and the capacitor C5 is electrically connected to the terminal 2 of the control chip 211, and the terminal 2 of the resistor R3, the resistor R4 and the capacitor C5 is electrically connected to the ground GND. It should be noted that the resistor R3, the resistor R4 and the capacitor C5 constitute the first differential module 214 to improve the response speed of the control chip 211 and adjust the voltage value of the input control chip 211 more quickly.

[0028] Specifically, the control module 21 also includes a second filter module 215, and the second filter module 215 is electrically connected to the terminal 3 of the control chip 211 and the ground GND. Among them, the second filter module 215 includes a capacitor C2, and the capacitor C2 has a terminal 1 and a terminal 2. The terminal 1 of the capacitor C2 is electrically connected to the terminal 3 of the control chip 211, and the terminal 2 of the capacitor C2 is electrically connected to the ground GND. It should be noted that the capacitor C2 can effectively reduce high-frequency noise and provide current loop compensation for the control chip 211.

[0029] Specifically, the control module 21 also includes a second differential module 216, and the second differential module 216 is electrically connected to the No. 5 terminal of the control chip 211 and the ground GND. Among them, the second differential module 216 includes a capacitor C3, a capacitor C4 and a capacitor R2, and the capacitor C3, the capacitor C4 and the capacitor R2 have a No. 1 terminal and a No. 2 terminal respectively. The No. 1 terminal of the capacitor C3, the capacitor C4 and the capacitor R2 is electrically connected to the No. 5 terminal of the control chip 211, and the No. 2 terminal is electrically connected to the ground GND. The working principle of the second differential module 216 is the same as that of the first differential module 214, which will not be repeated here.

[0030] Specifically, the control module 21 further includes an adjustment module 217, and the adjustment module 217 is electrically connected to the terminal 4 of the control chip 211 and the ground GND. The adjustment module 217 includes a resistor R1, which has a terminal 1 and a terminal 2. The terminal 1 of the resistor R1 is electrically connected to the terminal 4 of the control chip 211, and the terminal 2 thereof is electrically connected to the ground GND.

[0031] Further, the voltage follower module 22 includes an operational amplifier OP1 and a working power supply VIN. The operational amplifier OP1 has a terminal 1, a terminal 2, a terminal 3 and a terminal 4. The terminal 1 of the operational amplifier OP1 is electrically connected to the switch module 23; the terminal 2 of the operational amplifier OP1 is electrically connected to the terminal 1; the terminal 3 is electrically connected to the control module 21; and the terminal 4 is electrically connected to the working power supply VIN. Among them, the terminal 3 of the operational amplifier OP1 is electrically connected to the terminal 8 of the control chip 211. It should be noted that the terminal 2 of the operational amplifier OP1 is electrically connected to the terminal 1 to form a feedback loop to stabilize the output signal, reduce output fluctuations, and enhance the anti-interference ability of the circuit; the terminal 4 is electrically connected to the working power supply VIN, and the working power supply VIN provides power for the operational amplifier OP1; the control chip 211 sends a signal through the terminal 3 of the operational amplifier OP1, and outputs it from the terminal 1 to the switch module 23.

[0032] Further, the switch module 23 includes a MOS transistor Q1, which has a drain D1, a gate G1 and a source S1, the drain D1 of the MOS transistor Q1 is electrically connected to the rectifier circuit 10, the gate G1 of the MOS transistor Q1 is electrically connected to the voltage follower module 22, and the source S1 of the MOS transistor Q1 is electrically connected to the control module 21. Among them, the gate G1 of the MOS transistor Q1 is electrically connected to the terminal 1 of the operational amplifier OP1, and the source S1 of the MOS transistor Q1 is electrically connected to the terminal 2 of the control chip.

[0033] In the specific implementation, the mains is connected to the PWM drive power circuit, the mains inputs the AC power to the rectifier module 10, the rectifier module 10 converts the AC power to DC power and steps down the voltage internally, and inputs the stepped-down DC power to the gate D1 of the MOS tube Q1, thereby the control chip 211 sends the PWM drive signal to the outside through the 8th terminal. At this time, the PWM drive signal passes through the operational amplifier OP1, and the operational amplifier OP1 adopts the characteristics of the voltage follower module 22, that is, the PWM drive signal input to the operational amplifier OP1 is equal to the PWM drive signal output from the operational amplifier OP1, and the source S1 of the MOS tube Q1 is electrically connected to the ground GND of the control chip 211. Since the operational amplifier OP1 is used as the voltage follower module 22, the PWM drive signal will not be attenuated during the transmission process, and at the same time, the voltage of the gate G1 is greater than the voltage of the source S1, so the driving power of the PWM drive signal is sufficient to turn on the MOS tube Q1. After the MOS tube Q1 is turned on, the DC power input by the rectifier module 10 can flow into the load circuit 30 through the MOS tube Q1. It should be noted that the operational amplifier OP1 acts as a voltage follower module 22, and the driving power of the PWM driving signal is not weakened by the line resistance of the transmission line such as the ground line, so that the driving power of the PWM driving signal is sufficient to drive the conduction of the MOS tube Q1, thereby controlling the operation and shutdown of the load circuit 30; when the MOS tube Q1 needs to be turned off, the PWM driving signal is sent through the operational amplifier OP1 to the gate G1 of the MOS tube Q1 through the 8th terminal of the control chip 211. At this time, the PWM driving signal sent is a low-level signal, which is less than the voltage of the source S1 of the MOS tube Q1, thereby turning off the MOS tube Q1, thereby controlling the shutdown of the load circuit. In this embodiment, the rectifier module 10 uses a full-bridge rectifier, and the internal step-down adopts a BUCK circuit.

[0034] The above is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A circuit for improving PWM driving power, characterized in that: The invention comprises a rectifier circuit (10), a control circuit (20) and a load circuit (30); the control circuit (20) comprises a control module (21), a voltage follower module (22) and a switch module (23); the control module (21) is electrically connected to the voltage follower module (22) and the switch module (23) respectively; the voltage follower module (22) is electrically connected to the switch module (23); and the switch module (23) is electrically connected to the rectifier circuit (10) and the load circuit (30).

2. A circuit for improving PWM driving power according to claim 1, characterized in that: The control module (21) comprises a control chip (211) and a driving power source VCC (212); the control chip (211) has terminals 1 to 8; the driving power source VCC (212) is electrically connected to terminal 7 of the control chip (211); the voltage follower module (22) is electrically connected to terminal 8 of the control chip (211); and the switch module (23) is electrically connected to terminal 2 of the control chip (211).

3. A circuit for improving PWM driving power according to claim 2, characterized in that: The control module (21) further comprises a first filter module (213), wherein the first filter module (213) is electrically connected to terminal No. 1 of the control chip (211) and to a ground GND.

4. A circuit for improving PWM driving power according to claim 2, characterized in that: The control module (21) further comprises a first differential module (214), wherein the first differential module (214) is electrically connected to terminal 6 of the control chip (211) and to a ground GND.

5. The circuit for improving PWM driving power according to claim 2, characterized in that: The control module (21) further comprises a second filter module (215), wherein the second filter module (215) is electrically connected to terminal No. 3 of the control chip (211) and to a ground GND.

6. The circuit for improving PWM driving power according to claim 2, characterized in that: The control module (21) further comprises a second differential module (216), and the second differential module (216) is electrically connected to terminal 5 of the control chip (211) and to a ground GND.

7. The circuit for improving PWM driving power according to claim 2, characterized in that: The control module (21) further comprises an adjustment module (217), and the adjustment module (217) is electrically connected to terminal No. 4 of the control chip (211) and to a ground GND.

8. The circuit for improving PWM driving power according to claim 1, characterized in that: The voltage follower module (22) comprises an operational amplifier OP1 and a working power supply VIN, the operational amplifier OP1 having a terminal 1, a terminal 2, a terminal 3 and a terminal 4, the terminal 1 of the operational amplifier OP1 being electrically connected to the switch module (23); the terminal 2 of the operational amplifier OP1 being electrically connected to the terminal 1; the terminal 3 being electrically connected to the control module (21); and the terminal 4 being electrically connected to the working power supply VIN.

9. The circuit for improving PWM driving power according to claim 1, characterized in that: The switch module (23) comprises a MOS tube Q1 having a drain D1, a gate G1 and a source S1; the drain D1 of the MOS tube Q1 is electrically connected to the rectifier circuit (10); the gate G1 of the MOS tube Q1 is electrically connected to the voltage follower module (22); and the source S1 of the MOS tube Q1 is electrically connected to the control module (21).

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