IC for low power current gain 3.3V 50ma

Discussion in 'The Projects Forum' started by zcream, May 9, 2011.

  1. zcream

    Thread Starter Member

    Feb 21, 2009
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    I have a pulse that is approx 5ma at 3.3V
    This needs to drive a device that needs 50-100ma at 3.3V
    I can supply 3.3V or 5A for operational voltage.

    any idea what IC I could use for this ?

    I know I can build a current gain circuit from a npn transistor, but I am hoping that a low power current amp is available as a standalone IC.
     
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    An IC vs one logic-level MOSFET?

    Ken
     
  3. zcream

    Thread Starter Member

    Feb 21, 2009
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    Just realized there are logic-level MOSFETs. Would you advise on the suitability of a BJT or MOSFET for driving 100ma approx. ?
    I also realized that a MOSFET does not need a bias resistor at these low currents.
    Only gotcha may be that I am using 3.3V not 5V
     
  4. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    2,574
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    Try an STP22NF03L from DIGIKEY...$1.10. It should meet your 3v logic switching and your load requirements. Down side may be that it's in a TO-220 case. Is that a problem?

    Ken
     
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
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    That part is not spec'ed for Vgs<5V.
    Fairchild has a boatload of logic-level MOSFETs spec'ed for Vgs=2.5V. Other companies also have them.
     
  6. zcream

    Thread Starter Member

    Feb 21, 2009
    20
    0
    To-220 is actually good. I hate soldering SMDs. But it turned out my project had a problem with the clock frequency. So maybe I wont need this at all.
     
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