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.