Design of a Single Chip, Single Core, ZVS Buck Converter in MHz Domain

Venturing into MHz switching frequency promotes the integration of inductive DC-DC converter into mobile devices. Combining GaN power switch with low-loss ferrite core materials opens up new possibilities for high-frequency operations. In this work, we investigate the design of a single core inductor and single chip half-bridge switch for ZVS buck converter. Design guidelines are accompanied by preliminary performance assessment via simulations. To demonstrate the performance of our device, we fabricated and tested a 20 W prototype converting 6 − 12 V to 4 V at 2 MHz switching frequency. The prototype achieves η > 90 % at P
out
> 15 W and power density of 9.26 W/m
²
with < 5 mm thickness.