Help to Identify SMD part!...

Discussion in 'General Electronics Chat' started by nieves32, Feb 25, 2013.

  1. nieves32

    Thread Starter New Member

    Feb 25, 2013
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    Hello Forum!

    I ask for your help please to identify this SMD parts with the ledgend "GGG 72A" I think that there are a Diodes, but I do not know wich are. The circuit is a Poe injector.

    Thanks in advance for your help!...

    Best regards!...
     
  2. sheldons

    Active Member

    Oct 26, 2011
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    they are both diodes
     
  3. t06afre

    AAC Fanatic!

    May 11, 2009
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    Yeah...but what kind of diode is it. That would be a lot more helpful:rolleyes:
     
  4. t06afre

    AAC Fanatic!

    May 11, 2009
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    I recognize the white components as Comgap gas discharge tube (GDT) surge
    arrester devices. Has used them my self in medical devices. I also recognized the symbyl on the SMD as a symbol used on components from Vishay. That lead to that the components probably was some kind of transient voltage suppressors. And indeed that was correct The GGG is the type marking. And since it has no markings it is bi-directional
    http://www.vishay.com/docs/88394/88394.pdf
    http://shpat.com/docs/elfa/06050009.pdf
     
  5. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Looks like they go from the two power rails to the ground plane, it's really unlikely they are rectifier diodes.

    My guess is that (like the two gas arrestors) they are some type of transient protection, like transorbs or even MOVs.
     
  6. takao21203

    Distinguished Member

    Apr 28, 2012
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    Measure them with a DMM continuity tester. Schottky give some 110 to 200mV. Regular diodes- 500mV.

    Coils give nearly zero Ohms.
     
  7. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    bi-directional Transorbs have a CA suffix.
     
  8. t06afre

    AAC Fanatic!

    May 11, 2009
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    Oh thank you pointing that out. Important then ordering. But I do not the CA suffix is icluded on the SMD package. To me it looks like they use band/no band
     
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