Pre tracking pre regulator

Discussion in 'General Electronics Chat' started by dmta, Nov 14, 2013.

  1. dmta

    Thread Starter Member

    Mar 24, 2013
    32
    1
    Hi all,
    How do I use the LM2678 as a tracking pre regulator?
    regards
     
  2. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    I assume you mean you will use it to feed a linear reg to reduce power dissipation. You need to make a reference that is about 3V higher than the output and reference the LM2678 to that voltage (Vout + 3V). In that way there will be a constant voltage drop of 3V across the linear regulator.
     
  3. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,986
    745
    Do you want to make it variable or fixed output, for variable see pages 10-14.

    Datasheet
     
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