Analysis of Avalanche Behaviour for Paralleled MOSFETs

In this study, an avalanche extension to existing quasi-dynamic thermal model is developed. And the current and thermal distribution among paralleled devices under avalanche condition is investigated. The statistic distribution of breakdown voltage, terminal stray inductance and thermal coupling all affect final electrical and thermal balance of paralleled devices. Without careful design consideration, it may cause reliability problem. So conclusions in this paper could provide useful guidelines for high power discrete or module applications with paralleled power devices.