Comparison of different three-stage DC-DC converter solutions for SMPS applications

Energy savings and the reduction of CO2 emissions is a main topic in todaypsilas power electronics research. Power electronics offers a wide potential for energy savings. This contribution deals with the benefits and the challenges of pre-regulated and post-regulated three-stage DC-DC converters in server applications. They are compared to a state of the art two-stage DC-DC converter. This publication shows the advantages, problems and limits of current fed pre-regulated and voltage fed post-regulated three-stage topologies. The focus is on post-regulated converters and selected technical challenges during the development. Furthermore aspects regarding benefits of resonant gate drive for synchronous rectification MOSFETs and stage synchronisation are discussed. All results are extracted from practical measurements on the basis of different 12 V, and 800 W demonstrators. Efficiency considerations are shown as well.