I read a lot about MOSFET protection and built this scheme.
simulate this circuit – Schematic created using CircuitLab
I was thinking that gate and DS are protected enough but experience showed that I was wrong. I made 3 PCB's and all blowed. Motor during continous work takes 20A but I'm sure that overcurrent or power loss wasn't reason why MOSFET blown.
1. Why it doesn't work?
Now I know that D2 should be between R2 and SW1 but what else could cause damages?
2. How can I make it possible most failure-free?
I've seen scheme where between drain and gate was added bidirectional TVS diode but whether it is better solution than unidirectional TVS diode between source and drain?