MOS tube explosion problem
1 Overview
When we make power products or motor controllers, MOS tubes often break. I believe that more than 90% of hardware engineers will encounter this kind of problem in their career. However, this kind of problem is always hard to guard against. We often joke that engineers who have never burned pipes are not considered entry-level engineers. So why do MOS tubes break easily?
In high-power power electronic products, we will perform drive tests on power devices including MOS tubes or drive circuits as needed, including single and double pulse tests. So what parameters are we doing to determine these parameters? It mainly determines the MOS turning on and off GS waveform and DS waveform. The main causes of damage to MOS tubes are GS oscillation and overshoot, voltage failure caused by DS oscillation overshoot, short-circuit failure due to the direct connection between the upper and lower tubes, and thermal failure.
2. Relevant parameters of MOS tube
VDSS: The maximum voltage value applied between the drain and the source.
VGSS: gate and