Buck circuit with overvoltage protection circuit

Abstract

The invention discloses a Buck circuit with an overvoltage protection circuit. The Buck circuit with an overvoltage protection circuit comprises a Buck circuit, a heating device shorting circuit and asafety device F1. The heating device shorting circuit comprises a heating assembly R1, and the heating assembly R1 is tightly attached to the safety device F1. When the Buck circuit outputs an overvoltage, the heating device shorting circuit is connected, and the heating assembly R1 generates heat to cut off the safety device F1. According to the invention, when the output voltage is too high dueto failure of the Buck circuit, the heating device shorting circuit can be connected in time, and therefore, the heating component R1 is promoted to generate heat. Because the safety device F1 is tightly attached to the heating assembly R1, the heat of the heating assembly R1 can cut off the safety device F1, and the voltage input of the Buck circuit is disconnected. Therefore, the Buck circuit is prevented from outputting an over-high voltage, back-end equipment connected with the Buck circuit is prevented from being damaged due to overvoltage, electronic elements of the whole circuit are protected, and stable and safe operation of the circuit is ensured.

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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