过压保护电路

Abstract

本实用新型涉及电路技术领域，具体公开一种过压保护电路，包括电压检测模块、比较器模块、供电模块以及低边开关模块；电压检测模块用于检测输入电压源对电路的输入电压，并将检测到的输入电压反馈给比较器模块，比较器模块可根据判断输入电压源的输入电压与预设的对于负载的过压保护阈值的大小，控制低边开关模块的通断，从而控制过压保护电路的通断，以实现对负载的过压保护的效果。通过采用快速检测和切断电压源的方式实现过压保护，有效避免了因能量冲击导致的元件温升问题，提升过压保护的可靠性和稳定性。

Claims

1. An overvoltage protection circuit for overvoltage protection of a load, characterized in that It includes a voltage detection module, a comparator module, a power supply module, and a low-side switch module; The comparator module includes a comparator chip, a reference voltage source, and a fourth resistor; the first end of the fourth resistor is connected to the reference voltage source, and the second end of the fourth resistor is connected to the non-inverting input pin of the comparator chip. The voltage detection module includes a first resistor and a second resistor; a first end of the first resistor is connected to an input voltage source, and a second end of the first resistor is connected to both the inverting input pin of the comparator chip and the first end of the second resistor, while the second end of the second resistor is grounded; the comparator chip receives a reference voltage from the reference voltage source through a non-inverting input pin and receives a sampled voltage from the voltage detection module through the inverting input pin. The input terminal of the power supply module is connected to the input voltage source, and the output terminal of the power supply module is connected to the power supply pin of the comparator chip. The low-side switching module includes a first MOSFET; the first terminal of the first MOSFET is connected to the output pin of the comparator chip, the second terminal of the first MOSFET is connected to the ground pin of the comparator, the third terminal of the first MOSFET is connected to the low end of the load, and the high end of the load is connected to the input voltage source.

2. The overvoltage protection circuit of claim 1, wherein, The first MOS transistor is a first N-channel MOS transistor, the first electrode is the gate of the first N-channel MOS transistor, the second electrode is the source of the first N-channel MOS transistor, and the third electrode is the drain of the first N-channel MOS transistor.

3. The overvoltage protection circuit of claim 2, wherein, The comparator module further includes a fifth resistor; the first end of the fifth resistor is connected to both the output terminal of the power supply module and the power supply pin of the comparator chip, and the second end of the fifth resistor is connected to both the output pin of the comparator chip and the gate of the first N-channel MOS transistor.

4. The overvoltage protection circuit of claim 3, wherein, The low-side switching module further includes a second N-channel MOS transistor; the gate of the second N-channel MOS transistor is connected to the output pin of the comparator chip and the second end of the fifth resistor simultaneously; the source of the second N-channel MOS transistor is connected to the source of the first N-channel MOS transistor and the ground pin of the comparator chip, and the drain of the second N-channel MOS transistor is grounded.

5. The overvoltage protection circuit of claim 4, wherein, The low-side switching module further includes a sixth resistor; the first end of the sixth resistor is connected to the output pin of the comparator chip, the gate of the first N-channel MOSFET and the gate of the second N-channel MOSFET, and the second end of the sixth resistor is connected to the source of the first N-channel MOSFET and the source of the second N-channel MOSFET.

6. The overvoltage protection circuit of claim 1, wherein, The power supply module includes an NPN transistor and an eighth resistor; the collector of the NPN transistor is connected to both the input voltage source and the first end of the eighth resistor, the emitter of the NPN transistor is connected to the power supply pin of the comparator chip, and the second end of the eighth resistor is connected to the base of the NPN transistor.

7. The overvoltage protection circuit of claim 6, wherein, The power supply module also includes a second Zener diode; the negative terminal of the second Zener diode is connected to both the base of the NPN transistor and the second terminal of the eighth resistor, and the positive terminal of the second Zener diode is grounded.

8. The overvoltage protection circuit of claim 1, wherein, The comparator module further includes a first Zener diode; the first Zener diode is reverse-connected between the reference voltage source and ground.

9. The overvoltage protection circuit of claim 8, wherein, The comparator module further includes a third resistor; the first end of the third resistor is connected to a reference voltage source, and the second end of the third resistor is simultaneously connected to the first end of the fourth resistor and the negative terminal of the first Zener diode; the positive terminal of the first Zener diode is grounded.

10. The overvoltage protection circuit of claim 1, wherein, The comparator module further includes a second capacitor; one end of the second capacitor is connected to both the second end of the fourth resistor and the non-inverting input pin of the comparator chip, and the other end of the second capacitor is grounded.

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