An improved technique for the voltage source to drive the active soft switching cell applied to buck converter

This paper proposes a new technique in capable of both zero-voltage-transition (ZVT) and zero-current-transition (ZCT) switching for synchronous buck converter. This technique employs the coupled winding on the output inductor in the flyback-mode for generating the voltage source. It is used to provide soft-switching for all of the used switches with the resonance. In this paper, the basic operations are analyzed in detail and verified by experimental results from a prototype for 200W power supply.