Improved Control of GaN-based Active-clamped FIyback Converter with Shorter Reverse Conduction Time

As GaN HEMT can achieve high switching frequency of several MHz easily, it was widely used in resonant converter for high power density. In this paper, the reverse conduction of GaN HEMT within active-clamped flyback (ACF) converter is analyzed, and a novel control method is proposed to reduce the reverse conduction related power loss. In order to verify the proposed control strategy, a 12V-3A GaN-based ACF is designed and fabricated. The experimental results show that the reverse conduction time is reduced from 300ns to 20ns, which contribute to a 1.2% increase in efficiency. The proposed control method is implemented by FPGA.