A resonant drive circuit for GaN power MOSHFET

The rapid development of the research on Gallium Nitride semiconductor material and the unique properties of GaN (such as high electron mobility and saturation velocity, high sheet carrier concentration at hetero-junction interfaces, high breakdown voltages, and low thermal- impedance) make the material promising in high-power, high-temperature applications. Accordingly, a design for a drive circuit for GaN switches is increasingly in demand. Until now, however, specific gate drivers for GaN switches are not available yet. In this paper, a new resonant drive circuit for GaN power MOSHFET switches is discussed. This circuit employs a resonant LC tag to recover part of the power back into the voltage source in order to reduce the power loss. It also applies a topology which can increase the voltage level relative to the energy supply, generate the zero and negative gate-source voltages required to turn the GaN MOSHFET on and off, and make the circuit highly tolerant to input signal timing variance. This function reduces the overall power consumed in the driver and thus reduces the power loss. This is particularly important for high-frequency driver operation, to take full advantage of the superior switching speed of GaN devices. In this paper, the topology of the low-power-loss, high-speed drive circuit will be introduced and the simulation results will be discussed.