Dual BC547 NPN Transistor IC?

Discussion in 'General Electronics Chat' started by cce1911, Oct 6, 2013.

  1. cce1911

    Thread Starter Member

    Jun 11, 2013
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    I have a circuit that requires 2 BC547's in a T0-92 package. Is there a dual version of this IC in a PDIP package?
     
  2. paulktreg

    Distinguished Member

    Jun 2, 2008
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    Don't think so?
     
  3. t06afre

    AAC Fanatic!

    May 11, 2009
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    Not that I know about. But why do you need such a part?
     
  4. cce1911

    Thread Starter Member

    Jun 11, 2013
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    I'm just trying to reduce the number of components that I need buy and assemble. My circuit simply takes a momentary input and outputs a pulse based on the RC time constant.
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    You may just get away with a single 2n7000, Two components.
    Max.
     
  6. cce1911

    Thread Starter Member

    Jun 11, 2013
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    Max,
    Are you suggesting to get rid of the 2nd NPN and the 10K resistor and only go with a single MOSFET?
    -Capel
     
  7. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Yes.
    The original 2n7000 was designed as a FET darlington equivalent, named a 'Fetlington'!
    And was intended to interface TTL and CMOS to higher loads and voltages.
    But I always keep lots on hand and found them a real work horse in the right application.
    You keep the 10k load and the first 100k on the input.
    It just might work for your circuit.
    Max.
     
  8. cce1911

    Thread Starter Member

    Jun 11, 2013
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    What about leakage? I would like the 3v button cell to last as long as possible. The switch is only triggered intermittently and I don't want to have to change the battery every day or two.
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
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    There used to be pages in the data books of dual transistors & JFETs for external long-tailed pair on the front end of op amps.

    Usually in a 6 pin TO18 or TO5, they were designed to be closely thermally and parameter matched.

    They're not so popular as they once were, but you may find something that's a very near equivalent to the 547.

    The BC547 was pretty much the cheap plastic version of the BC107, so that might help when comparing parameters.
     
  10. cce1911

    Thread Starter Member

    Jun 11, 2013
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    Max, I can't take the second NPN out. That's my TTL logic inverter.
     
  11. ronv

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    Nov 12, 2008
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