A Dual-Mode Direct-Drive D-GaN Driver with Reused Inductor and Power Switches for Negative Voltage Generation and Gate Energy Recycling

This paper presents a dual-mode direct-drive driver for depletion-mode GaN (D-GaN) power transistors, integrating negative voltage generation and gate energy recycling with reused inductors and switches. D-GaN devices offer superior reliability and gate voltage swing but require complex drive schemes and incur significant gate driving losses in high-power, high-frequency applications. The proposed driver combines an inverting buck-boost converter with a resonant gate driver, operating in resonant direct-drive (RDD) mode for efficient gate energy recycling at high frequencies and conventional direct-drive (CDD) mode for adjustable slew rate control. Fabricated in a $0.18 \mu \mathrm{m}$ HV BCD process, the driver achieves a gate charging efficiency of 93 % and reduces power consumption by up to 40 % in RDD mode.