A power supply protection circuit

Abstract

The invention discloses a power supply protection circuit. The power supply protection circuit comprises a power supply chip and a protection circuit, wherein an input end of the power supply chip and a first input end of the protection circuit are respectively used for receiving input voltage signals; an output end of the power supply chip is used for transmitting output voltage signals to a second input end of the protection circuit, and transmitting output voltage signals to post-stage power supply equipment; an enable control end of the power supply chip is connected with an enable output end of the protection circuit, and is used for receiving enable signals output by the protection circuit; when the output voltage signals are within a threshold voltage range preset by the protection circuit, the protection circuit outputs a first enable signal to the power supply chip through the enable output end, and controls the power supply chip to operate normally; and when the output voltage signals exceed the threshold voltage range preset by the protection circuit, the protection circuit outputs a second enable signal to the power supply chip through the enable output end, and controls the power supply chip to be in a steady state. The power supply protection circuit achieves the overvoltage and undervoltage protection of the post-stage power supply equipment through the protection circuit.

Description

technical field [0001] The invention relates to power supply technology, in particular to a power supply protection circuit. Background technique [0002] With the improvement of the precision of electronic products, the electronic products have higher and higher requirements for voltage, and thus higher and higher requirements for power supply (Power). [0003] In the prior art, a power supply chip with internal overvoltage protection is usually selected to perform overvoltage protection for the subsequent power supply equipment. like figure 1 As shown, it is a schematic diagram of a power supply system provided by the prior art. The power supply system includes a power supply chip 10 and a subsequent power supply device 20 , the power supply chip 10 has overvoltage protection, and the power supply chip 10 is preset with an overvoltage protection voltage. Specifically, the output terminal of the power supply chip 10 is connected to the subsequent power supply device 20, ...

AI Technical Summary

Problems solved by technology

[0004] The power supply chip 10 in the prior art has a built-in overvoltage protection. The overvoltage protection voltage is a constant protection voltage of the power supply chip 10, which can only protect the body of the power supply chip 10 and cannot protect the power supply equipment 20 of the subsequent stage.

When the output voltage signal is higher than the allowable input voltage of the power supply device 20 of the subsequent stage and does not exceed the overvoltage protection voltage of the power supply chip 10, the power supply chip 10 still works normally, and the power supply device 20 of the subsequent stage is easy to burn out under the overvoltage state.

In addition, the current power supply chip 10 does not have undervoltage protection, and when the subsequent power supply equipment 20 works in an undervoltage state for a long time, it is easy to cause damage to the subsequent power supply equipment 20

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