Novel integrated transformer winding scheme for self-driven ZVS interleaved asymmetrical half-bridge for telecommunications quarter brick

Presented in this paper is a new method of increasing the output current of a quarter brick by integrating multiple gate drive and power windings on a single transformer core. Proposed is a two interleaved asymmetrical half-bridge structure that achieves ZVS on both legs and are mutually connected to an innovative transformer structure. The transformer structure transforms the two asymmetrical waveforms on the primary side to a symmetrical waveform on the secondary. This configuration is ideal for driving the synchronous rectifiers. The synchronous rectifiers are self-driven utilizing the same power transformer. A 750 kHz 1.2 V-80 A prototype is built in the quarter brick form factor that achieves 84.7% efficiency at 48 V input.