Minimizing Switching Losses in High Switching Frequency GaN-based Synchronous Buck Converter with Zero-Voltage Resonant-Transition Switching

GaN power switching devices are promising candidates for high switching frequency and high efficiency operations due to their lower on-resistance and faster switching capabilities compared to conventional silicon power devices. As the switching frequency increases up to the MHz-level, soft switching plays an important role to further minimize the switching losses and improve the efficiency. In this paper, a GaN-based synchronous buck converter operating with zero-voltage resonant-transition (ZVRT) switching in synchronous conduction mode is proposed. The ZVRT switching converter offers a favorable trade-off between switching and conduction losses especially in GaN-based DC-DC converters. The efficiency of the ZVRT switching converter providing 20 W output power from 28 V input voltage improves up to 7% at 3 MHz switching frequency.