Go Down

Topic: Arduino driving MOSFET (Read 345 times) previous topic - next topic

btfdev

Hiya,

Just need a quick confirmation from the experts here.

Using Arduino PWM output, we can supply required voltages (0V to 5V) to drive a logic level MOSFET?

Thinking about using a 10 turn pot mapping to the Arduino output, it should be precise enough to do the job.

Thanks, BTFDev

retrolefty


Hiya,

Just need a quick confirmation from the experts here.

Using Arduino PWM output, we can supply required voltages (0V to 5V) to drive a logic level MOSFET?

Yes that will work. Many recommend adding a series 200-330 ohm series resistor between the pwm pin and the mosfet gate pin to limit current flow during transition switching of the capacitance load of the mosfet. Also if the mosfet drain circuit is wire to a DC voltage source other then the arduino +5vdc then a 10k resistor wired between gate and source terminals of the mosfet will insure that the device remains turned off in the case where the arduino might get powered off but the mosfet external voltage source is still on.


Thinking about using a 10 turn pot mapping to the Arduino output, it should be precise enough to do the job.

That should work ok, but keep in mind that the pot input allows 10bits of resolution of the analog input converter but the analogWrite command only has 256 bits of resolution, so a precision pot's capability may not be able to be fully utilized over say a quality single turn pot which may be good enough.
Lefty
Thanks,

BTFDev

Krodal

A logic level mosfet will turn on with a "logic level", as the name says.
Most normal mosfets will be on at 9V or so, and can't be driven directly by an Arduino.

But some logic level mosfets turn on at 2V, others turn on at 4V. You can find in the datasheet how much current the mosfet is able to control at a certain gate voltage.

To find a logic level mosfet, you could search Ebay for "logic mosfet".

Go Up