Bridgeless ac-dc converter with power factor correction and method therefor

Abstract

In one form, a bridgeless AC-DC converter includes a totem pole network having a first input adapted to be coupled to a second terminal of an AC voltage source, a second input adapted to be coupled to a first terminal of the AC voltage source through an inductor, an output terminal for providing an output voltage, and a return terminal, an output capacitor coupled between the output terminal and an output ground terminal, a sense element coupled between the return terminal and the output ground terminal, and a controller circuit coupled to the return terminal of the totem pole network. The controller circuit modulates an on time of an active switch in the totem pole network on a cycle-by-cycle basis by shortening the on time corresponding to an amount of time a current sense signal derived from a current through the sense element exceeds a current limit threshold.