Hello All. I'm seeking recommendations for a logic level mosfet to use in driving a 200ma, 5vdc, non-inductive load. Something small and cheap would be nice. Thanks - Scotty
SMT or through-hole?
What gate voltage? 5v? 3.3? less?
My favourite small mosfet is NTD5867NL. It works with 5v on the gate and handles a few amps with ease. They are cheap. I bought mine from RS Components.
There are others but make sure they are fully on at 5v on the gate.
Weedpharma
That sort of spec MOSFET are nearly all SMT. A BJT switching transistor would be much
easier to find in through-hole, 2N2222 or similar. TO220 size MOSFET would of course do
but more expensive than smaller devices.
NTD5867NL
That sounds like a good device for a significant load but, after looking at figures 1 and 4 of the data sheet, I'm not sure it would perform well at 200ma. I was preferring a mosfet because of their higher efficiency when used as a switch compared to a bjt. Not a big deal though since it's not battery powered. Perhaps the 2N2222 will do. Thanks all. - Scotty
You can certainly dig around on digikey, and come up with a few 5v gate fets in through-hole. Most are grossly oversized for what you're doing, and accordingly more expensive (50-70 cents before qty discount), and you have to look very carefully at the specs to make sure they'll actually work at 5v on the gate. Just filtering by logic level feature isn't enough - a lot of them only provide acceptable performance at 10).
If you're looking for SMT, I default SI23xx series, which is SOT-23. 2302 is plenty for your needs, works off 2.5v gate, handles a couple of amps (which is mind boggling if you look at the tiny rice-grain sized package), and is ~5 cents a piece on ebay in lots of 50-100. For slightly more, you can get ones that'll handle ~6A, or work with even lower gate drive. Oh, and for gate voltages below 4.5v, the "logic level drive x.x volts" filters in the digikey catalog work pretty well.
The difference between SMT and throughhole is just stunning, isn't it? I made a bunch of these to address the problem
I can recommend AOI514, AOI516 from digikey.
I used 32 of them on this board with gate switched by 74HC595 outputs.
http://www.crossroadsfencing.com/BobuinoRev17/
