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LP5009: OK to operate with VCC off and LED supply on? How much current?

Michael McClary
Prodigy 50 points
Part Number: LP5009

We have an application where we'd like to have the regulated VCC supply to the LP5009 turned off (0V) but the LEDs fed from the raw supply, behind the cutoff (to avoid loading the regulator with the LED currents).  So the LEDs would still be powered (about 4.2V).

Is it OK to have OUTn pulled up while VCC is 0V?  If so, will the output drivers be solidly off and how much leakage current will be drawn by the OUTn pins through the LEDs?

  • 0
    TI__Genius 12915 points

    Hi Micheal,

    It is OK to pull up out pins (less than 6V) when no VCC supply ans the leakage current would be around 0.1uA.

  • 0 in reply to Hardy Wu
    Prodigy 50 points

    Hardy Wu said:

    It is OK to pull up out pins (less than 6V) when no VCC supply ans the leakage current would be around 0.1uA.

    Thank you.  That's most of my answer, and enough to base the design decision.

    Can you also answer this, for power estimation:

    • Is that 0.1uA total or per OUTn, so that the nominal leakage would be 0.9uA?
    • This is nominal.  Is there a max?

    (I will mark this answered tomorrow even if you don't reply to the followup questions, but am leaving it open so you can see them.  Thanks again.)

  • 0 in reply to Michael McClary
    TI__Genius 12915 points

    Hi Michael,

    This is typical value per OUTn. Sorry that we have no maximum data.