H-Bridge with mosfets in parallel

[Ch_Irawan]

Hi,

I want to build a high current low voltage H-Bridge but can not source the proper mosfet, so how about paralleling the mosfet?

The mosfet candidate is IRFZ44 with IR2104 driver, need to drive about 60A at 24V max. The first think come to mind is the gate capacitance will be higher, maybe doubled? What will the effect to the driver?

-ichan

[izua]

I'm a fan of the BUZ mosfet series myself. Look into those, you'll have good currents.
If gate capacitance will be high, overall speed will be affected.

[epineh]

I would think you will be fine with parallel irfz44's, using a gate driver chip. I use them on my H bridge, not paralleled though, just put one diode/resistor combination per gate on each FET and it should work.

Have a look for the OSMC H Bridge, this should give you some idea of paralleling, From memory they use four FET's in parallel per leg.

Russell.

[bunalmis]

You need higher current mos driver if you drive parallel mos.
Else turn on and turn off time extend.

But frequency is importand. If switching frequency is low you can use common looking drivers.