Hi!

I'm developing motor driver for DC servo motor(Maxon Motor 150W).
But something came up that I could not understand.

I used gate driver(IR2101) for Mosfet turn on/off. Refer the circuit that i attached file.
I turn on the Q4 FET and gave PWM signal to Q1 FET(Q2,Q3 is off). Then motor operate quite well. But I load the motor Q2 FET is burning(PWM duty<100%). This I could not understand.

I try PWM period 1~200kHz and add snubber(many kind). But I cannot solve this problem.

Is anyone know how to solve this problem?

 

Q2 burns when you PWM Q1 (Q4 on) or when you PWM Q2?

 

Q2 FET Burn when PWM Q1.

 

Are you sure that the Vgs of Q2 is less than 2V?

If not it will partially conduct and get hot.

By burn you mean it gets hot?

 

Well, it gets hot, but continues operation it really burn up.
I burnt more than 10.

And Q2 is less than 2V. Even I tried that put -15V at Q2 gate.

 

Are you certain your physical circuit is free of debris and/or solder bridges?