At 11:09 PM 7/28/2008, you wrote:
>We're looking for a simple high-side switching FET. A 2N3906 would work, but
>for this design it's preferable to leave out the base resistor. Is there a
>transistor similar to the 2N7002, in terms of characteristics, and cost?
>
>Digikey and Google spew out hundreds of results for "p-channel fet", however
>the cost is considerably higher.
>
>Thanks in advance for your help.

Just keep limiting the search parameters until the number of choices
becomes reasonable. It doesn't take much to get down to a couple of pages,
from which you can see several choices between 0.05 and 0.10 in reel lots.

You do run the risk of missing something that way without doing
a bit more work (eg. I limited to SOT-23 packages, ignoring other
packages such as SC-70). The BSS84 will show up from several makers.

Go back and check more deeply and you'll find stuff like the more expensive,
but  rather nice NTA/NTE4151 which is rated for 1.8V drive and has a nice low
Rds(on) in an SC-75/89 package.

Of course an MMBT3906 or 4403 will be considerably cheaper in parts cost
in volume (less than half).

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com



-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist