H-Bridge DC motor driver

Thread Starter


Joined Sep 5, 2006
I need help in designing a H bridge motor driver circuit to drive a DC permanent motor.
The H bride is similar to the attched circuit.
But instead of using IGBT, I need to use MOSFET.
The circuit also need to have optocoupler (each connected to the MOSFET).

The optocoupler will be controlled by a function generator (around 5V).

The motor specs are:
Type: dc permanent magnet motor.
Voltage rating: 180 Volts dc
Power: 500W

The supply specs are:
High voltage, high current (60V, 3A) fixed dc is to power the motor.
An external low power transformer with primary rated for 230V, and two secondary coils of 12V ratings is available to provide the power required for the gate drive circuit.

The difficulties I have is I don't how to choose the MOSFET i need to use, don't know how to choose the optocoupler I need to use.
I read somewhere that I need to use both N-MOSFET (enhanced) and P-MOSFET (enhanced). Why need to use enhanced MOSFET and not depletion MOSFET..? The only thing i know about MOSFET is for N-MOSFET, the source is connected to GND and for P-MOSFET, the drain is connected to GND.

I really need help.. Can somebody please help me.. Thanks..



Joined Mar 1, 2007
why does it have to be mosfets?
i think mosfets with that high of working voltage is difficult to find.
igbt's is ok with and usually designed for high voltage, don't you think so?



Joined Oct 22, 2007
am new member here
i have dc-motor 12V 20A
i want to designe the drive circuit for it and be variable speed using pwm by PIC
for the high current i should use IGBT or MOSFETS
am need help for what should i use.?


Joined Jul 17, 2007
You should start your own thread. Posting a new question to someone else's thread is known as "hijacking" - even though it is similar in nature.