I'm new to electronics, and I have a question. Let's imagine you have something in parallel that drives in total 100 mA. To turn it on and off you use a pin from your microcontroller, but the pin can deliver at maximum 15 mA.

If you decide to use a N channel MOSFET, it won't help because the current is provided by the gate. But if you decide to use a P channel MOSFET, the current should be provided by the source (let's say a power supply), and it works.

Am I right to think like that ? Does it mean that it is a big advantage when using P channel ?

Thanks you very much for your help.

  • \$\begingroup\$ I think you are certainly wrong to think like that. \$\endgroup\$
    – Andy aka
    May 7, 2018 at 10:12
  • \$\begingroup\$ I can imagine. I kinda got that the gate does not drive current. It is just used as a switch. So I guess the gate is high impedance. (I mean it drives current for sure, but something negligible) \$\endgroup\$
    – Fever
    May 7, 2018 at 13:54
  • \$\begingroup\$ for most uses, you want an N-chan, they run cooler and are easy to switch with an MCU \$\endgroup\$
    – dandavis
    May 7, 2018 at 18:34

1 Answer 1


Unlike Transistor, it's CE current is controlled by ib (NPN transistor). A MOSFET is a voltage controlled switch. Take an N channel MOSFET as a example: when the gate voltage Vgs is highly enough Vgs>Vth, then the MOSFET turns on, the current will flow from the Drain to the Source .


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