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 Pin numbering of Diodes 

Last post Fri, Sep 18 2009 4:05 AM by C Shiva. 5 replies.
Started by C Shiva 15 Sep 2009 11:16 PM. Topic has 5 replies.
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  • Tue, Sep 15 2009 11:16 PM

    • C Shiva
    • Top 50 Contributor
    • Joined on Tue, Jul 15 2008
    • Bangalore, Karnataka
    • Posts 159
    • Points 3,220
    Pin numbering of Diodes Reply

     Hello,

       As per library standard, the pin no.1 of all diodes and other components like battery should be anode or positive. But i'm seeing some violation of this standard and got confused. Am i went wrong? If anyone there known more about this issue, please help.

    Regards,

    Shiva.

    • Post Points: 35

  • Wed, Sep 16 2009 8:32 AM

    • Randy R
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    • Joined on Wed, Jul 16 2008
    • Dupont, WA
    • Posts 160
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    Re: Pin numbering of Diodes Reply

    We've seen the same thing.  One manufacturer will mark the anode and another will mark the cathode.  It was finally decided to just put the diode symbol in the silkscreen.

    G'Day, R².
    • Post Points: 5

  • Wed, Sep 16 2009 10:43 AM

    • redwire
    • Top 10 Contributor
    • Joined on Thu, Jul 17 2008
    • Allen, TX
    • Posts 813
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    Re: Pin numbering of Diodes Reply

    Actually that is backwards from IPC. Pin 1 is always cathode on a diode.
    • Post Points: 20

  • Thu, Sep 17 2009 9:29 PM

    • C Shiva
    • Top 50 Contributor
    • Joined on Tue, Jul 15 2008
    • Bangalore, Karnataka
    • Posts 159
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    Re: Pin numbering of Diodes Reply

     Redwire, If you have such documents regarding IPC standards of pin numbering, may you please upload it in here. It will give me more information.

    Thanks.

    • Post Points: 20

  • Thu, Sep 17 2009 10:56 PM

    • redwire
    • Top 10 Contributor
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    • Allen, TX
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    Re: Pin numbering of Diodes Reply
    Normally you need a membership with IPC to get these.  However, I found that IPC is publishing this for free.  Scroll down to the section titled "IPC-7351 Surface Mount Land Pattern Zero Orientation"
    • Post Points: 20

  • Fri, Sep 18 2009 4:05 AM

    • C Shiva
    • Top 50 Contributor
    • Joined on Tue, Jul 15 2008
    • Bangalore, Karnataka
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    Re: Pin numbering of Diodes Reply

     Thanks Redwire. Good information.

    • Post Points: 5
Page 1 of 1 (6 items)
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Started by C Shiva at 15 Sep 2009 11:16 PM. Topic has 5 replies.