Overvoltage protection circuit used in power factor corrector and power factor corrector

Abstract

The invention provides an overvoltage protection circuit used in a power factor corrector and the power factor corrector, wherein the overvoltage protection circuit comprises a current-voltage switching circuit, a reference current-reference voltage switching circuit, a static overvoltage comparing circuit, a dynamic overvoltage comparing circuit and an overvoltage synthesizing circuit; the current-voltage switching circuit is used for switching a current signal output by an error computing amplifier to a first voltage signal and outputting the first voltage signal to the static overvoltage comparing circuit and the dynamic overvoltage comparing circuit; the reference current-reference voltage switching circuit is used for switching the reference current signal of a current source to a second voltage signal and outputting the second voltage signal to the dynamic overvoltage comparing circuit; the static overvoltage comparing circuit is used for comparing the voltage value of the first voltage signal with the voltage value of the reference voltage of the static overvoltage comparing circuit and outputting a static overvoltage signal; the dynamic overvoltage comparing circuit is used for comparing the voltage value of the first voltage signal and the voltage value of the second voltage signal and outputting a dynamic overvoltage signal; the overvoltage synthesizing circuit is used for synthesizing the static overvoltage signal and the dynamic overvoltage signal, controlling the shut-off of a power element and realizing quick shut-off of the power element.

Description

technical field [0001] The invention belongs to the field of analog integrated circuits, in particular to an overvoltage protection circuit used in a power factor corrector and the power factor corrector. Background technique [0002] With the rapid development of integrated circuits, the chip area is getting smaller and smaller. The impact of power supply technology on the performance of the entire chip is also becoming more and more important. In order to improve switching power supply efficiency and reduce power grid pollution, power factor correction technology has increasingly become a research hotspot in the field of power supply design. [0003] In the field of switching power converters, any circuit structure that makes the input grid current non-sinusoidal, or even if it is a sine wave but out of phase with the sinusoidal input voltage, or makes the input current have harmonics will reduce the power factor and cause power loss. In general applications, adding capa...

AI Technical Summary

Problems solved by technology

[0004] However, at present, there is no overvoltage protection for the power factor corrector in the power supply circuit using the power factor corrector. Therefore, when the power is turned on and the output voltage of the power factor corrector exceeds the rated , Welding and other problems, it is easy to cause damage to the electronic components inside the power supply. Therefore, when the output voltage of the power factor corrector exceeds the rated value, protecting the electronic components in the power supply circuit from being damaged is a technical problem that needs to be solved urgently.

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