A 250 kHz/560 W phase modulated converter

Phase modulated full bridge topology has emerged as the most suitable choice for high power, high voltage SMPS applications requiring high power densities. Its distinguishing features are zero voltage switching (ZVS) and constant frequency operation. In this paper, the various factors affecting the ZVS characteristics of this new topology are discussed in detail and design procedures for each of these components are developed. The concept of ZVS LIMIT is introduced. The various trade-offs involved in the design are brought out. A full-fledged 560 W/250 kHz off-line SMPS, using the phase modulation concept is designed and developed. The simulated and experimental results are presented in detail.