Electronic – TC426 Mosfet drivers keeps blowing out

brushless-dc-motordrivermosfet

i made this BLDC motor controller, here is schematic
enter image description here

But TC426 Mosfet drivers keeps blowing out when i connect a load, after drivers fail, mosfets are still working, only drivers blows out, I checked all voltages, they are fine. I am using 33kHz pwm modulation for each phase and mosfets are IRF44N. I can't find a problem, but i was thinking that i need to put resistor between mosfet gate and driver? Could that be a problem?
enter image description here

Thanks for everybody who answered. While you were answering, i tried to do some more testing and i have started to see some pattern, last three times first mosfet driver failed, in schematic it is left driver. I will double check all connections, but I think i will redraw PCB taking all your advice because i am tired going to electronics shop every day and spending money there for drivers! Thanks everybody

UPDATE
I added capacitors to each driver and change mosfets to more powerfull ones, now everything works, thanks to everybody!

Best Answer

I'd be looking at the signal rise time at the inputs of the TC426.

The TC426 has a mosfet input, meaning it is capacitive. You have not indicated the MCU voltage, or how long that cable is, but if the rise time is slow at the TC416 end, it will leave the TC426 output shorted for a considerable duration.

Running the signal ground back through the power ground is also a bad idea. If there is a significant rise on that ground it may drop your digital input into the grey area, again creating a short inside the TC426. You should consider decoupling those control signals, perhaps with opto-couplers to keep the signal ground completely separate from the power ground.

Also, more capacitor storage is needed close to the TC426s as indicated in the spec sheet.

Related Topic