Sensing Gallium Nitride HEMT junction temperature using gate drive output transient properties
The gate drive output transient properties of conventional power semiconductors (Silicon MOSFET, Silicon Carbide MOSFET, and Silicon IGBT) have been studied for online junction temperature (Tj) sensing. This method utilizes the semiconductor intrinsic Tj dependent characteristics and the gate drive output dynamics. In this paper, the method is applied to Gallium Nitride (GaN) high electron mobility transistors (HEMTs) To demonstrate the GaN HEMT Tj sensing, two passivated die HEMTs are implemented in a half bridge and driven by two integrated push pull type gate drives. The gate drive turn on current transient is used for GaN HEMT Tj sensing. The "gate drive HEMT" switching properties are modeled to explain the Tj dependent gate drive output dynamics. Experimental results are compared with LTSpice simulations.
2016 IEEE Applied Power Electronics Conference and Exposition (APEC)