Do i need to use mosfet driver component for h-bridge design

mosfet drive

hi,

i want to design a h-bridge to control a dc motor. (24V ~15A). i chose mosfet as power switching element. do i need to use mosfet driver component or not?. if i need why? isn't it enough to drive a mosfet drectly using dc voltage.

mosfet drive

You can drive a MOSFET gate with a simple DC voltage or an ordinary logic device, assuming it has sufficient voltage swing, but for many applications the driver chip has important advantages. Especially when you want to switch the MOSFET on and off at high frequency. Power MOSFETs have large gate capacitance, so it takes amps to switch them on/off fast.

Re: mosfet drive

in h-bridge at the high-side, is there any problem to drive the mosfet drectly? because at the high-side, the source of the fet is not connected to the ground. it is connected to the motor. how can i sure that i have a 15V between source and gate. if you have a sample design can you sent it?

Re: mosfet drive

look at this site:

https://www.infineon.com/cgi-bin/if...BV_EngineID=ccceaddfgfiggmjcflgcegndfifdfoh.0

this have some integrated devices for motor control, for design a bridge with discrete components you need some experience .... if not the life of the bridge will be reduced ...

Re: mosfet drive

You can drive MOSFET directly from CMOS ICs (12V) for lower side of H-bridge.
You can drive higher side of CMOS H-bridge through voltage divider.

Re: mosfet drive

Hi

mosfet driver will guarantee that the voltage between the high side gate and source is more than 15Vdc which consequently will drive the mosfet in a +ve temperature coefficient , so the mosfet will not go anyway in a thermal run way and it will not burn .


the driver will drive the mosfet gate with a high current pule which will charge the gate source capacitance , then after charging the 15Vdc will start to appear between the gate and the source .

so briefly :

1- provide 15Vdc with respect to a floating point .

2- provide a fast switchig by charging the Cgs .

note as i know that every 10 degree raise in the componant temp will half its life .

there is no problem for the low side while it is tied to the ground ,i.e. not floating like the high side .

salam
hindi