Modified asymmetrical ZVS half-bridge DC-DC converter

Abstract

A modification is proposed for the asymmetrical zero-voltage-switched (ZVS) half-bridge DC-DC converter topology that substantially changes the static transfer function and the voltage stress distribution within the converter power mesh. This modification allows the converter circuit to be optimised for higher efficiency and power density. It is also postulated that the modification with its corresponding benefits can be utilised in other complementary driven topologies. Although the asymmetrical H-B converter is inherently capable of ZVS switching, only the proper choice of parameters can insure ZVS in all modes of operation. The DC circuit analysis and design procedure for the power stage components are presented. Experimental results, in good agreement with the analysis, are presented for a 300 W converter operating at 500 kHz, with 5 VDC/60 Amp output, and 84% efficiency at 75 W/in/sup 3/.