PFC Power Supply and Control Method Thereof

Abstract

A PFC power supply includes a PFC circuit converting an AC power source into an intermediate power source and a PWM circuit converting the intermediate power source into an output power source. A power controller controls the PWM circuit and includes an AC voltage detector and a protection circuit. The AC voltage detector detects the AC power source to provide a power-good signal. The protection circuit provides an input-power protection for the PWM circuit when the power-good signal indicates normality of the AC power source. When the power-good signal indicates abnormality of the AC power source, the input-power protection is disabled or eased, so that the PWM circuit continues converting the intermediate power source to support the output power source.

Dependencies are inferred from the claim text.