SMD component identification

Discussion in 'General Electronics Chat' started by kevco, Sep 25, 2009.

  1. kevco

    Thread Starter New Member

    Sep 24, 2009
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    SMD component identification - I have a SOT-23 with a marking 20A can anyone help me identify?

    Thanks,

    Kevin
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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  3. Externet

    AAC Fanatic!

    Nov 29, 2005
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  4. kkazem

    Active Member

    Jul 23, 2009
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    One of the best ways of narrowing down SMT parts is to determine the manufacturer from the logo, which even in SMT parts is almost always stamped or etched into the top of the plastic part. Then, its easy to find sites that show the logos of all semiconductor and electronic part manufacturers. Once you've determined the mfg, and you have the marking, you're 90% there and if all else fails, call the manufacturer and ask the customer service people or the applicfation engineers.

    Regards,
    Kamran Kazem
    kkazem
     
  5. kevco

    Thread Starter New Member

    Sep 24, 2009
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    Thanks for all your replies -

    I couldn't find the manufacturing logo anywhere; it looks like a flipped-up Lexus logo without the circle around it. The properties of the three terminals are - two have 230ohm both direction and no reading on the third. Checking a good device with a Huntron I only see the 230ohm and no junctions on any of the terminals. In the circuit the two terminals next to each other are connected together, the device sits parallel in the base emitter junction of an IGBT.

    20A[​IMG]
     
  6. SgtWookie

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    Jul 17, 2007
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  7. kevco

    Thread Starter New Member

    Sep 24, 2009
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    Thank you for these sites, all good links however for the life of me I still can’t identify the SMT markings, nor can I figure out what type of component it is.

    Kevin

    SMT23 markings - 20A /
     
  8. sillyfrog

    New Member

    Sep 29, 2009
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  9. rand0man

    New Member

    Feb 25, 2013
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    It's almost certainly a MOSFET rated for 20 Amps

    To find out if its PNP or NPN and the necessary upper voltage tolerance you'll have to look closer at the circuit layout.

    This based on the knowledge that the gate of a MOSFET is electrically isolated from the source and drain. So it makes sense that there's no reading on the third pin.

    Greetings
    Rand0man
     
  10. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    Mosfets are neither NPN nor PNP, mosfets are N or P. And you seriously think that if it really were a mosfet, that it would have the current rating marked on it? And why not voltage rating? :rolleyes:
     
  11. forumro

    New Member

    May 23, 2013
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    Hello,

    I have a problem with identifying a component. Can you give me a hand?

    It's a SMD, first line : AḄ

    second: murata logo followed by a 4. Thank you!
     
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