A novel single-stage off-line converter with PFC, fast output voltage regulation and reduced switching frequency range

摘要

A single-stage LC resonant AC/DC converter with fast output voltage regulation and PFC is described. Variable switching frequency control is used to regulate the output voltage. A new control method is introduced whereby the duty cycle is varied to regulate the output voltage at lighter loads. This enables a drastic reduction in the switching frequency range. Experimental results from a 5 V, 20 A prototype are presented.