Zener diode test question

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  • billy66
    Senior Member
    • Mar 2010
    • 124

    #1

    Zener diode test question

    I have a surface mount zener diode and I want to make sure it is good/bad. I believe it may be shorted, but not sure. Here is the data sheet:

    http://www.taitroncomponents.com/cat...et/TZT2.0W.pdf

    The diode is part number: TZT7.5YW

    When testing resistance across pins 1-3... I get 21 ohms... Max Zener Impedence is listed as 23... does this mean I'm ok? Or am I grossly misunderstanding this?

    Thanks for any and all help
  • Th3_uN1Qu3
    Believe in
    • Jul 2010
    • 6031
    • Romania

    #2
    Re: Zener diode test question

    So it's a 7.5 volt. Remove it from the board and hook it up to a 12v power supply with a 1k resistor in series. Resistor goes from cathode (pin 3 in this case) to +12v, anode goes to ground. If you don't get 7.5 volts across the diode in this arrangement then it is bad.
    Originally posted by PeteS in CA
    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
    A working TV? How boring!

    Comment

    • billy66
      Senior Member
      • Mar 2010
      • 124

      #3
      Re: Zener diode test question

      Thanks, I'll give that a try... if I can dig up a power supply.

      Comment

      • billy66
        Senior Member
        • Mar 2010
        • 124

        #4
        Re: Zener diode test question

        .2V, it's bad... thanks for the help.

        Comment

        • Th3_uN1Qu3
          Believe in
          • Jul 2010
          • 6031
          • Romania

          #5
          Re: Zener diode test question

          .2v is consistent with your 21 ohm resistance reading (apply voltage divider rule). It's bad alright.
          Originally posted by PeteS in CA
          Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
          A working TV? How boring!

          Comment

          • billy66
            Senior Member
            • Mar 2010
            • 124

            #6
            Re: Zener diode test question

            Will this work in its place:

            http://www.mouser.com/Search/Product...1-BZX84C7V5W-F

            Comment

            • Th3_uN1Qu3
              Believe in
              • Jul 2010
              • 6031
              • Romania

              #7
              Re: Zener diode test question

              Yup, will do.
              Originally posted by PeteS in CA
              Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
              A working TV? How boring!

              Comment

              • billy66
                Senior Member
                • Mar 2010
                • 124

                #8
                Re: Zener diode test question

                Thanks... I thought so, just ordered.

                Comment

                • billy66
                  Senior Member
                  • Mar 2010
                  • 124

                  #9
                  Re: Zener diode test question

                  Worked perfect, thanks!

                  Comment

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