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Help required with unknown device

  1. Feb 21, 2012 #1
    Hi

    I'm having problems identifying a component on a PCB and i was wondering if anyone here could shed some light on what this device is...


    http://db.tt/i1V3uqZf

    Anyhelp is appreciated

    Rgds


    Phil
     
  2. jcsd
  3. Feb 21, 2012 #2

    jedishrfu

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    Staff: Mentor

    my guess is its a crystal and the labeling of fcc13 fcc14 ... kind of indicates that
     
  4. Feb 21, 2012 #3

    jedishrfu

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    if you know what the board is you might be able to get a schematic online or a user guide.
     
  5. Feb 21, 2012 #4

    berkeman

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    I think you are right about it being a frequency source, but my guess would be a programmable oscillator. Especially since they all have the same overall marking, the difference would be in how they are programmed.

    This is a similar part:

    http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=us&KeyWords=AP3S3EJ-ND

    When ordering it from Digikey, you tell them what frequency you want them programmed to. I recently ordered some at 38.4000MHz, and the other was 39.3216MHz.
     
  6. Feb 21, 2012 #5

    jedishrfu

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    I think you nailed it. the device looks remarkably similar to the OP's picture.
     
  7. Feb 21, 2012 #6

    vk6kro

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    Science Advisor

    You could narrow the search a bit by measuring the resistance from each output pin to the other pins on one of these devices.

    Draw up a diagram of the resistances, if any, that you find.

    Also note how each of those things are connected to each other via the printed circuit board. Do the power supply lines seem to go through all of them?

    The FCC bit makes it sound like an interference filter. FCC is the American Govt agency that deals with radio interference, among other things.
     
  8. Feb 23, 2012 #7
    Looks like a common mode choke or transformer.

    Take a multimeter and test for continuity between the pins. If it beeps between any 2 pins it's either a transformer or choke.


    @Berkemen, are you sure it's a Surface mount crystal?
    The part in the ckt, looks more like a plastic box than a SMD component.
     
  9. Feb 23, 2012 #8

    berkeman

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    Yeah, looks like an SMT part to me from that view. Kind of similar to an SO-8 package, but with only 4 leads. I could be wrong, of course.
     
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