At 03:31 PM 2/12/02 -0800, Dave King wrote:
>Hi
>
>Just wondering if anyone has any information or know of any on-line for
>interfacing a
>power transistor. I'm trying to drive about a non-inductive 2 amp load.
>This circuit for
>lack of a better description would be the blinking led on steroids. The
>signal is 2 pulses
>(1/10th duration) at 1hz. Board voltage is 3.3vdc.

Do you have a higher supply voltage available?  Most FETs - even logic
level FETs - will not fully enhance below 4V.

You can use a Darlington bipolar transistor: one NPN part I use is
TIP121.  Feed the base with a 220R resistor (Ib ~ 10 mA if Vdd=3.3V).  The
collector will handle 2 Amps easily - but with a fairly nasty saturation
voltage of about 1V.

If you DO have a higher supply available, use it to turn on a MOSFET.  For
example, where is your 3.3V derived from?  Can you use that?

dwayne


Dwayne Reid   <dwayner@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax

Celebrating 18 years of Engineering Innovation (1984 - 2002)
  .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-
     `-'   `-'   `-'   `-'   `-'   `-'   `-'   `-'   `-'
Do NOT send unsolicited commercial email to this email address.
This message neither grants consent to receive unsolicited
commercial email nor is intended to solicit commercial email.

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics