Switching Transistors - SOT

Hi Guys

Can anyone suggest a suitable npn transistor, preferably sot footprint, and its pnp compliment suitable for switching a load of up to, say, 1A at 12v d.c.? I’m currently using an ATMega328P controlling a 2N2222 and 2N2907 pair to switch the 12v supply. However I want to reduce the circuit to an smd design and at the same time increase the switched current from its present 400mA (approx) to around 900mA.


Google : "NPN PNP smd transistor 1A"

First responce : http://www.futurlec.com/TransSMD.shtml

Make your choice

Thanks 68tjs.

I did try a quick google (nothin' like it first thing in the morning :* ), but didn't find anything available local to me in the UK, other than some PBSS4160DPN dual npn/pnp devices which have me tempted. They're a tad more of a hassle to incorporate in the board design, but not too much so. I may look for some suitable smd FETs instead.


SMD fets are your best bet and available in SOT 23 packages. An equivalent Bi-polar design would use an SOT223 part and require heatsinking of some sort unless it were a low duty cycle switching waveform.


In SOIC8 format the PBSS4032SPN NPN-PNP superbeta pair will do 30V and 4A nicely.

You might want to use something like Digikey or Mouser to do your parametric search (transistor -> bipolar -> surface mount -> 1A+ ...), get some part numbers back, and then look for those from whatever local supplier carries similar brands.

Good ideas there guys, many thanks.

I've decided to go with some IRLL014 mosfets. I can get them from Farnells in the UK and they have the added advantage of having an Eagle library available!