Incorrect operation of the Allegro A3941 driver
I think your A3941 drivers keep burning out because you are using a power supply instead of a battery.

The FETs you are using have diodes to catch the voltage spikes from switching the motor on and off.

These diodes short the spikes to the power rail (12V.)

If that were a battery, then it would absord the spikes and all is good.

Many powersupplies can't do that.  The spike hits, and the voltage on the rail jumps.  Most of the time, it jumps a little and your driver gets to go on living.  Sometimes it jumps a lot, and exceeds the input voltage limts of the A3941.

You can check it out by attaching a scope to the 12V while the controller is running.  Watch for spikes, or even just excessive noise on the 12V rail.



Given that your driver is operating at 84kHz, I don't know why you would hear an audible squeal from the motor at low speed.

Maybe someone else can explain that.