Split-Path Bootstrap GaN MIS-HEMT Gate Driver for Fast Switching of Power Devices

Gallium Nitride (GaN) devices offer excellent switching performance and high efficiency, making them ideal for next-generation power converters. At high operating frequencies and power densities, fast gate control is essential to reduce switching losses and thereby alleviate thermal stress. This paper introduces a novel split-path bootstrap gate driver topology designed to achieve ultra-fast switching transitions with low propagation delay. Utilizing a shared bootstrap capacitor for both the high-side pre-driver and an optional pull-up transistor, the proposed circuit improves area efficiency and supports higher power density. Circuit simulations using the GaN MIS-HEMT ASM model demonstrate short rise/fall times of 9 ns/6 ns, propagation delays of 16 ns/11 ns, and a maximum operating frequency of 8 MHz under a 2 nF capacitive load. These characteristics make the proposed driver well-suited for efficient operation in MHz-range power converters, with great potential for monolithic GaN integration.