Dynamic Reliability of IC-Interface GaN HEMTs Demonstrated Under Ultra-Fast (ns), High-Frequency (MHz) Gate Overvoltage Stress (>30V)
Abstract
The small gate overvoltage margin is of real concern in p-gate GaN HEMTs in converter applications. Recently, ICeGaN® (Integrated Circuit Enhancement-mode GaN) device deploys a monolithically integrated power IC interface to expand the static operation window to be similar to those of Si MOSFET and Si IGBT. However, the dynamic response of the IC interface under nanosecond gate bias (VG) overshoot, as well as the gate reliability under megahertz switching frequency (fSW), have never been studied. This work addresses this gap by developing a new circuit to generate the application-like V G overshoot profiles with dVG/dt up to 10 V Ins andfsw up to 3 MHz. The IC interface is shown to respond in nanosecond and clamp the VG,IN below 7 V under an external V G overshoot up to 80 V and dVG/dt of 7 V Ins. Uniquely for p-gate GaN devices, ICeGaN shows no degradation under long-term overvoltage stress under 30-V VG overshoot at 3-MHzfsw. This is the first report of the dynamic response of GaN monolithic gate protection ICs under ultra-fast overshoot. Test results reveal that the on-chip IC interface can substantially enhance dynamic gate reliability and robustness of p-gate GaN HEMTs.
