With the circuit below:
Q2 and Q4 burn down when 15A is injected into the circuit. Q4 burns even if it were never activated.
The gate voltage control is 0 or 12V to activate a particular channel.
I've tried to add protection components (zener / res on the gate), but it still burns down.
I don't really get why. The circuit is referenced to the ground with Q3 and Q6 forward diod make sure the voltage drop is reasonable, which would create a dV of 1-2V. The shunt itself would make a dV of less than 0.1V which would give a Vgs of ~10V in the worst case which is plenty enough to drive the mos:
Is there something I am missing on this circuit?