A GaN HEMTs half-bridge driver with bandgap reference comparator clamping for high-frequency DC-DC converter

摘要

This paper presents a high-frequency half-bridge driver for GaN HEMTs with bandgap reference comparator clamping (BGRCC). Due to the characteristics of GaN HEMTs, the high-side supply voltage must be clamped to prevent it from exceeding the voltage limits in half-bridge configuration. The BGRCC scheme is simple and effective with low power consumption, which can adaptively keep the high-side supply voltage at an appropriate level. And the drive circuit for GaN HEMTs is specially designed and optimized to acquire low propagation delay as well as excellent mismatching delay. The simulation results show that the BGRCC scheme can clamp the high-side supply voltage at an average of 5.37 V with acceptable ripples and the maximum propagation delay for the drive circuit is around 22.6 ns when the switching frequency varies from 1 MHz to 10 MHz.