A new ZVS phase-shifted PWM DC/DC converter with push-pull type synchronous rectifier

摘要

A new ZVS phase-shifted PWM DC/DC converter with push-pull type synchronous rectifier is proposed. One half-bridge DC/AC inverter is cascaded with a push-pull type synchronous rectifier through an inductive link and a transformer. There is no inductor at the rectifier stage. In this converter, switching of the inverter is phase-shifted with respect to the synchronous rectifier. All switches have ZVS conditions. Constant switching frequency operation is achieved and all gate signals are 50% in duty cycle. The principles of operation of the converter are analyzed in detail. A prototype for 12 V/4 A operated at 200 kHz has been built. Experimental results are presented and they verify the analysis.