First, these are the components I'm using on my PCB, click on them to see the datasheets:
The schematic is attached below. Sorry if I'm not using some right symbols. I took the schematic from the PCB software.
Vbus voltage comes from rectified and filtered mains (110VAC). PWM frequency is 10 kHz.
The gate driver is isolated, so GND1 is ground from the rectifier, and GND2 is the digital ground.
I tested the PCB with two different PMDC motors:
These are the steps that I followed before the transistor blew:
I tested the circuit with a light bulb first. Everything ok.
Removed the bulb, then I connected Motor 1 with no load. Everything ok.
Removed Motor 1, I connected motor 2 with a slight load. It started ok at 5% of duty cycle. Then, I increased duty cycle to 10% and the transistor blew up, so the motor went to max speed uncontrollably.
I haven't programmed the fast overcurrent detection from the current sensor. That way I would have probably saved the MOSFET.
The question is... what could be the cause of this? high dv/dt and di/dt? need an snubber?
Update: I've blown up a second MOSFET at startup of the motor. I've replaced the FET with this IGBT IKW50N60DTP and so far it's working well. Anyways, I will capture some waveforms soon.
Go to this link to see a piece of the PCB where the parts are located: https://i.imgur.com/4UWVIGm.jpg