Advanced Gate Drive Unit for junction temperature monitoring and dynamic current balancing of GaN transistors operating in parallel

Abstract

Proposed new Gate Drive Unit (GDU) makes the gate of the power semiconductor switch (AlGaN/GaN High Electron Mobility Transistor (HEMT) a temperature sensor and/or a highly dynamic indirect current sensor. The method is based on a low current injection circuitry in the gate driver, where the instantaneous junction temperature, during operation of the power transistor, can be detected. This can be used as an indirect current sensor for balancing between parallel connected transistors as well as for fast and reliable overload/short circuit protection without any additional sensing components in the power module or on the power board circuitry. Using a simple modification of a conventional gate driver an inherently safe, more reliable power electronics equipment (AC/DC, DC/DC, Motor Drive Inverters) based on new WBG transistors can be obtained.