Totem pole power factor correction circuit and power conversion device using same

Abstract

A totem pole power factor correction circuit is disclosed. The totem pole power factor correction circuit is used to receive an input voltage and includes a fast upper switch, a fast lower switch, a slow upper switch, a slow lower switch, a capacitor filter circuit and a controller. The fast upper switch and the fast lower switch are connected in series, and the slow upper switch and the slow lower switch are connected in series. An endpoint voltage is formed between a midpoint of the electrical connection between the slow upper switch and the slow lower switch and a reference potential point. The capacitor filter circuit has an equivalent capacitance value. The controller is used to detect the input voltage and the endpoint voltage and output the first control signal to the fourth control signal to respectively control the operations of the fast upper switch, the fast lower switch, the slow upper switch and the slow lower switch. When the input voltage is in the zero-crossing interval, the controller adjusts the first control signal and the second control signal according to the set voltage slope and the endpoint voltage. Consequently, the slope of the endpoint voltage is changed and adjusted according to the set voltage slope.

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