开关电源中功率MOSFET管损坏模式及分析

结合功率MOSFET管不同的失效形态,论述了功率MOSFET管分别在过电流和过电压条件下损坏的模式,并说明了产生这样的损坏形态的原因,也分析了功率MOSFET管在关断及开通过程中发生失效形态的差别,从而为失效在关断或在开通过程中发生损坏提供了判断依据。给出了测试过电流和过电压的电路图。同时分析了功率MOSFET管在动态老化测试中慢速开通、在电池保护电路应用中慢速关断及较长时间工作在线性区时损坏的形态。最后,结合实际应用,论述了功率MOSFET通常会产生过电流和过电压二种混合损坏方式损坏机理和过程。

The failure mode and analysis of power MOSFET in switching power supply

The failure mode mechanism and reasons of over current and over voltage of power MOSFET are presented with the photos of their respective failure forms.The difference of power MOSFET failure at turn on and turn off are also discussed,which provides the guideline for the failure at turn on and turn off.The test circuits of over current and over voltage are also given.The failure principle of power MOSFET operating at the linear zone for a relatively long time for turn on during system burin in test and turn off in battery protection circuit are discussed with the failure photos.In the end,the combination failure modes of the over current and over voltage in real application are discussed.