Investigation of gate drive strategies for high voltage GaN HEMTs

Abstract

Gallium Nitride (GaN) devices due to its excellent material properties has the potential to significantly impact the power electronics industry. With the 600 V devices getting commercialised, there is an increasing demand to accelerate the adoption of these devices in power applications which requires know-how on dealing with these novel devices in real circuits. This paper studies the basic driving requirements of GaN switches when operated in half-bridge configuration. The stringent gate drive margin, instability issues due to high dv/dt and di/dt, cross talk due to parasitics, voltage overshoot and oscillations are analysed in detail using different gate drive circuits. This work will discuss the impact of the different gate drive strategies on the GaN switching performance. These findings are experimentally validated by designing, demonstrating and comparing 1 kW, 500 KHz GaN half bridge prototypes using three different types of gate drives.