The below circuit is an attempt at having 3 isolated bipolar switches able to handle +/-20A. Voltage is below 10V when "conducting/enabled" and below 200V when not.
IA1212 is an isolated DC/DC converter with 12V output.
While it "works", Q12 burns as the current increases. ~6A for a few seconds destroys Q12.
I'm not really sure why because Vs on Q12 would be 0V + Q13 reverse diode voltage, about 1.2V at 20A, which means the +12V - 1.2V => Vgs 11.8V which is way beyond the safe Vgs threshold of ~8V at 20A.
The goal of this circuit is to measure the current through different shunt resistors, as different ranges depending on the input current. The system needs to be bi-directionnal and controlled from 3V3.
Any ideas are welcome, additionally, there is perhaps a better implementation than this?