rlogiacco:
Paul__B:
A "logic level" FET will turn on at logic levels, but not fully. It really needs about 8 to 10 volts, so you need to under-rate a heavier device to get it to switch on sufficiently for your load.Ok, thanks, I wasn't aware of that. What info on the datasheet will deliver such information? I really thought a logic level MOSFET would have been fully turned on by a logic level... my bad
A logic level mosfet will fully turn on at some specific logic voltage level, that is why they are called 'logic level'. A specific device's datasheet will state at what gate voltage value will attain minimum Ron value, and any additional gate voltage above that gives no improvement. So in all such questions the datasheet for the specific device under consideration is the best source for such questions.