Method and circuit to improve output voltage regulation and noise rejection of a power factor control stage

摘要

A circuit for improving output voltage regulation of a power factor control stage providing power to a load. The circuit includes a voltage reference generating circuit that produces a voltage signal that is in phase lock with an input alternating current power line signal but is independent of voltage excursions of the alternating current line signal and unwanted voltage harmonics. The circuit also includes a control circuit receiving the voltage reference signal for controlling an electronic switch coupled to an input line providing power to the load. The electronic switch is pulsed on and off by the control circuit to force the current in the input line to the load to follow the reference voltage. The input alternating current line current is thus maintained in a substantially constant predetermined phase relationship with the input alternating current line voltage.