Replacement BJT for TP2222A

Discussion in 'Electronics Resources' started by bassplayer142, Sep 28, 2010.

  1. bassplayer142

    Thread Starter Active Member

    Jan 2, 2007
    89
    0
    Does anyone know a basic BJT that would replace a TP2222A seen in the link below? It is basically being used in an existing circuit to drive different color leds. Other Basic ones I have used didn't have the same effect. Thanks!
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Any old 2N2222 or 2N3904 should work.

    The statement:
    is kind of mysterious. Can you say how or why they did not work (or what they were, for that matter)?
     
    bassplayer142 likes this.
  3. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    I am a real lover of the 2N2222A and 2N2907A (I use it's cased plastic cousin, the PN2222A and PN2907A). There are literally hundreds of transistors that will replace either one. The odds are in favor it is the circuit around the transistor that makes the difference, not the transistor.
     
    bassplayer142 likes this.
  4. bassplayer142

    Thread Starter Active Member

    Jan 2, 2007
    89
    0
    Thanks everyone!
     
  5. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    I worked with electronics all my life and I have never seen a 2N2222.
    My first job was with Philips so I used their metal cased BC107 and BC157 (and BC108/BC158 and BC109/BC159) transistors then they changed them to plastic cased BC547 and BC557 (and BC547/BC558 and BC549/BC559). I also used higher current BC327 and BC337 transistors.
    Then I changed jobs and used North American 2N3904/2N3906 and higher current 2N4401/2N4403 transistors.
    The European and American transistors have the pins reversed.
     
  6. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Then you haven't worked for many companies making US military equipment. I've worked for 2, Rockwell International and Raytheon. Both of them use the heck out of this transistor in several different forms. Why I don't know, other than it is so. The odd thing is some are used in raw chip form for microelectronics, different manufactures look entirely different, though the part number is the same.

    I like it because it is cheap. In plastic form I paid 8¢ for them, SMT was 4¢.

    The 2N4401 almost identical, same collector current specs (600ma), slightly higher gain. You'd have trouble telling them apart. Radio Shack packs both in their 15 transistor assortment.

    Fairchild claims 1.0A for the collector current on the PN2222A, but I've seen others that use the 600ma number, same as the 2N4401

    2N4401

    2N2222
     
    Last edited: Oct 2, 2010
  7. Ghar

    Active Member

    Mar 8, 2010
    655
    72
    The 2N2222 and 2N2907 are definitely very popular... they have their own Wiki pages and come by default in the most sparse SPICE libraries and certainly appear on the preferred parts lists used by MIL standards.

    Then there's this quote:

    http://semiconductormuseum.com/Transistors/Motorola/Haenichen/Haenichen_Index.htm
     
  8. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,386
    496
    Same as Bill. In our electronics class, all transistor laboratory assignments were using 2N2222.
     
  9. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    You might not find two 2N2222 transistors the same. They will have different hFE and Vbe. If you replace a 2N2222 with a 2N4401 then you probably will not be able to measure a difference except for the varying hFE and Vbe.
     
  10. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,536
    Probably not even then, the two are very similar devices.

    2N2222 and 2N2222A are very old, and made by a lot of different manufacturers. I'm betting this makes for wider specs than most.

    But they are milspeced, and they are also cheap. Great combination!

    I have run into counterfeits though. Bummer.
     
Loading...