AlGaN/GaN Metal-Insulator-Semiconductor (MIS)-HFETs Based DC-DC Boost Converters with Integrated Gate Drivers

This study proposed a 100 kHz, 5V/11V boost converter with an integrated gate driver for a power switching device using recessed E-mode MIS-HFETs. The integrated gate driver consisting of multi-stages DCFL (Direct-Coupled FET Logic) inverters and a buffer stage, has large input swing (up to 10 V) and wide noise margin with gate dielectric, which benefits applications requiring large gate swing without any additional drivers or level shifters. The impact of transistor size on rise times and fall times have been studied. Either buffer stage or larger width of DCFL inverter can reduce rise times from 2.4 µs to less than 0.5 µs at 100 kHz, so the output voltage of boost converter is increased by 10 % at a duty cycle of 0.7. However, large buffer width can result in high gate overshoot and oscillation, indicating careful design to balance switching speed and oscillation.