I have a project in which I have to "close a digital switch" using either a 5V or a 3.3V supply. The load will be at 12V, with a required current of around 200mA.
As a newbie I thought to use an N-channel MOSFET such as the FQP30N06L datasheet.
While the transistor will actually provide me more than enough current, according to the datasheet, either at 3.3V or 5V, I will be in the saturation region and not in the ohmic region.
I thought I was fine with that, but reading around I found out you should be in the ohmic region to use the MOSFET as a switch.
Why so? Also: What are the downsides of my configuration (i.e. switching in saturation region)?