Investigation of the Temperature Measurement via VSD(T)-Method applied to Paralleled SiC MOSFET Chips during Power Cycling

Abstract:
Accurate junction temperature measurements are essential to obtain meaningful power cycling results. The purpose of this paper is to investigate the application of the VSD(T)-method to parallel-connected SiC MOSFET chips during power cycling. This shall answer the question how the temperature which is determined by measuring the junction temperature via the reverse voltage across parallel connected chips — as is common practise when modules with internally paralleled SiC MOSFETs are power cycled — correlates with the individual and potentially different chip temperatures. For this purpose, the junction temperatures are determined separately as well as considering the parallel connection like a single chip.