buck circuit with overvoltage protection circuit

Abstract

The present invention discloses a Buck circuit with an overvoltage protection circuit. The Buck circuit with an overvoltage protection circuit includes a Buck circuit, a heating device short circuit and a safety device F1. The heating device short circuit includes a heating component R1. The heating component R1 is in close contact with the safety device F1, and when the Buck circuit outputs an overvoltage voltage, the heating device short circuit is turned on, and the heating component R1 generates heat to cut off the safety device F1. In the present invention, when the Buck circuit fails and the output voltage is too high, the heating device can be connected in time to short-circuit the circuit, thereby prompting the heating component R1 to generate heat, and because the safety device F1 is close to the heating component R1, the heat of the heating component R1 can be cut off The safety device F1 disconnects the voltage input of the Buck circuit, thereby preventing the Buck circuit from outputting too high a voltage, thereby preventing the back-end equipment connected to the Buck circuit from being damaged due to overvoltage, and at the same time protecting each electronic component of the entire circuit, ensuring The stable and safe operation of the circuit.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to a Buck circuit with an overvoltage protection circuit. Background technique [0002] Buck circuit is a step-down chopper circuit, which is one of the basic DC-DC circuits. It is used for step-down conversion from DC to DC. The internal power conversion circuit of the electrical equipment adopts the Buck circuit, and its application range is very wide. [0003] The current power converters using the Buck circuit all have a failure mode in which the switch tube is damaged or the voltage feedback circuit fails, resulting in a high output voltage. Most of the switching tubes use MOSFETs, and most of the failures of MOSFETs are due to internal low-resistance conduction, which is equivalent to the output voltage being equal to the input voltage, and it is easy to damage the back-end circuit (equipment). Similarly, the failure of the voltage feedback circuit may also cause the ...

AI Technical Summary

Problems solved by technology

[0003] At present, the power converters using the Buck circuit all have the failure mode of the switch tube being damaged or the voltage feedback circuit failing, resulting in a high output voltage.

Most of the switching tubes use MOSFETs, and most of the failures of MOSFETs are due to internal low-impedance conduction, which is equivalent to the output voltage being equal to the input voltage, and it is easy to damage the back-end circuit (equipment)

Similarly, the failure of the voltage feedback circuit may also cause the output voltage to be too high

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