Motor driver problem - the D6 will become very hot

[omid_juve]

motor driver problem?

Dear my friend
please have a look at the attached drawing . this is a pwm motor driver . it really works and i test it. but the problem is that with any types of diode that i put instead of D6 in my circuit the D6 will become very hot . please give me an advise to correct my drawing.
Thanks

 

[FvM]

motor driver problem?

What's the load current? You may simply need a diode with a higher current rating. Even with a none-perfect gate drive, D6 shouldn't show higher losses. The bootstrap circuit most likely doesn't work with all possible duty cycles, but that's another topic.

 

[omid_juve]

Re: motor driver problem?

the load current is about 7A also can you please tell me what should be the frequency of the timer so az the mosfet and diode become less hot?