Totem pole PFC circuit and control circuit thereof

Abstract

A control circuit for a totem pole PFC circuit is disclosed. The totem pole PFC circuit includes a first half bridge and a second half bridge both coupled between an output terminal and a reference ground, the first half bridge is coupled to an inductor and includes a first switch and a second switch. The totem pole PFC circuit is used to receive an AC input voltage and provide an output voltage. The control circuit in the embodiments of the present invention can conduct the first switch or the second switch of the totem pole PFC circuit multiple times during the zero crossing period of the AC input voltage to gradually charge or discharge a switch node of the second half bridge, reducing the voltage slew rate of the switching node of the second half bridge, thereby improving the electromagnetic interference performance of the circuit and avoiding audio noise.

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