L200 Reference

Discussion in 'General Electronics Chat' started by Dritech, Jan 21, 2014.

  1. Dritech

    Thread Starter Well-Known Member

    Sep 21, 2011
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    Hi,

    I am using the L200 variable voltage regulator and would like to set the reference voltage to 0V. To do so, I supplied -2.77V instead of ground (on simulator). Why is the output not going to 0V when using this method?

    Any help will be appreciated.
     
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
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  3. crutschow

    Expert

    Mar 14, 2008
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    That technique will work with a 3-terminal regulator, such as the LM317, but not with the L200 which has a ground pin as well as a reference pin. If put both the reference pin and the ground pin at 2.77V below the circuit ground then it should adjust down to 0V (with respect to the circuit ground).
     
  4. Dritech

    Thread Starter Well-Known Member

    Sep 21, 2011
    756
    5
    Thanks for the replies. Is there a way to set the reference voltage to -2.77V without using a center tap transformer please?
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
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    Can you get hold on the LT3080 regulator. That goes down to 0 volt. It was a project on EEVblog using that regulator in a power supply project
     
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