A Monolithic Integrated E-Mode GaN 48V-to-1V DC-DC Buck Converter with PWM Control

In this paper, a fully-integrated gallium-nitride (GaN) half-bridge DC-DC buck converter is designed based on GaN-on-SOI (silicon-on-insulator) technology. A self-bootstrap gate drive circuit is designed to achieve rail-to-rail gate driving while reducing the conduction loss of the switch. A level shifter is designed to transfer the gate drive control voltage from the low voltage (LV) region to the high voltage (HV) region. In addition, we design a fully-integrated closed-loop pulse-width modulation (PWM) control module for the buck converter. We have simulated the direct 48V-to-1V DC-DC with a maximum load current of 5A. At 250kHz, the half bridge DC-DC buck converter can achieve a peak efficiency of 84.3% at a load current of 3A.