A Gate Driving Scheme for GaN GIT with Enhanced Short Circuit Capability for Motor Drive Application

Short circuit capability in power switching devices is highly desired for motor drive application, and it is a challenging issue for GaN power high-electron-mobility transistor (HEMT) devices because of concentrated heat generation and inefficient thermal dissipation that partially stems from much smaller die size. This paper proposes a current mode gate driving scheme with a shunt resistor in the gate loop for a GaN gate injection transistor (GIT) to prolong short circuit duration time and thus improve the system robustness and reliability. The shunt resistor not only can limit the short circuit peak current as a result of the source negative feedback but also can be used as a current sensing element that is indispensable for cost-sensitive motor control. The experiments demonstrate a greatly increased short circuit capability and no obvious compromise on other performances in motor drive application with the proposed gate driving scheme.