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dual complementary transistors

Discussion in 'Hobby Electronics' started by steve marchant, Jun 11, 2009.

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  1. Returning temporarily to hobby electronics after 30 years, can't find a
    non-SOT case version of a npn/pnp transistor combo. Eyes dim, hands shaking,
    can barely see the damn SOT things leave alone mount them on pcb. Any
    suggestions (may have common base internal connection and needs to switch at
    least 100 mA)?
     
  2. Phil Allison

    Phil Allison Guest

    "steve marchant" <
    ** What a strange question.

    PNP plus NPN pairs on the same chip are rare as hen's teeth - cos is is near
    impossible to make good devices in both polarities that way.

    Dual transistors in PNP and NPN are common, as that is the way to get
    excellent device matching for diff pairs et .

    For a complementary pair, for switching applicatons - for heaven's sake use
    TWO devices.

    How about BC639 and BC640 - glued together if you like ??



    ...... Phil
     
  3. At the time when this design was popular, using two transistors on the same
    substrate ensured they were more closely matched than any old two separates
    from a bin.

    I knew associates who bought many, and sat with a transistor tester for
    hours to find close matches.

    Today, you wouldn't do it anymore, there are better ways of doing just about
    everything. But if you're in the repair game, you might not have the luxury,
    funds or time to re-design from scratch...
     
  4. Phil Allison

    Phil Allison Guest

    "John Tserkezis"
    ** Shame you did not read my post before sniping it -

    FUCKWIT !!

    " PNP plus NPN pairs on the same chip are rare as hen's teeth - cos is is
    near
    impossible to make good devices in both polarities that way. "



    ..... Phil
     
  5. I never claimed I read any of your posts before snipping Phil.
     
  6. Phil Allison

    Phil Allison Guest

    "John Tserkezis Wog IDIOT "


    ** Seems to make no difference if you read them or not.

    Either way - nothing goes in to your impenetrable, autistic skull.




    ...... Phil
     
  7. Now, now Philthy. Calm down, make a good strong cup of tea and take a
    stress pill.
     
  8. Hmmmm... but knowing Philthy, he probably is like Rasputin the mad monk,
    who supposedly had hyperacidity and avoided sugar so cyanide probably won't
    do the trick. All rumour and conjecture of course.
     
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