Operation of single-chip mosfet and igbt devices after failure due to repetitive avalanche

This paper presents analysis of post-failure behaviour of MOSFETs and IGBTs operating in a series connected string. The aim of this experimental study is to analyse the operation of devices in case of sudden loss of controllability, leading to repetitive avalanche conditions at relatively low current and subsequent failure due to overheat. For redundant designs it is important that the devices are locked in stable conducting state after the failure and the string continue its operation.