onsemi NCP1681BAD2R2G, PFC Controller, 65 kHz

The ON Semiconductor NCP series of a PFC controller IC designed to drive the bridgeless totem-pole PFC topology. The bridgeless totem-pole PFC is a power factor correction architecture that consists of a fast switching leg driven at the PWM switching frequency and a second leg that operates at the AC line frequency. This topology eliminates the diode bridge present at the input of a conventional PFC circuit, allowing significant improvement in the power stage efficiency.

Digital voltage loop compensation
Skip mode in very light load condition
Near unity power factor in all operating modes
Prevents operation in audible range