I'm trying to select a suitable mosfet for a variety of tasks. I want one which can handle as much current as possible, but I want to keep my board small too. Typically I'd just choose one with a high continuous current rating and calculate the power dissipation, but one of the things I want to use this for is to PWM a small 12v motor at up to 46,875Hz. The motor would draw around 150mA at most I think.
I've been trying to figure out how to calculate how much heat is going to be generated switching a logic level mosfet with 3.3v and around 9mA of current.
I've been looking at several on Digikey:
And when sorting by price, I found this one stood out with an awfully high continuous current rating:
Seems to good to be true, so there must be some catch but I have yet to spot it.
Anyway, I've hit a bit of a road block. I believe the gate charge time will allow me to calculate how much time the mosfet is going to spend not fully on or off, but the rating is in "nC". Nano charge? What the heck is that? Is that just another word for farads? I've looked everywhere and it does seem to be nano-charge but I can't find any explanation of what this charge unit is.