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TPS25944A: FLT and PGOOD current capability

d_zero
Genius 4795 points
Part Number: TPS25944A

Dear *,

how much current can TPS25944A drive from FLT and PGOOD pin to direct drive a LED? Or do we need to add MOSFET?

Best Regards,

David.

  • 0
    TI__Guru** 105641 points

    Hi David,

    FLT and PGOOD pins can sink 5mA safely. Please take care to limit max. current under 10mA 

    Best Regards,

    Rakesh

  • 0 in reply to Rakesh
    Genius 4795 points

    Dear Rakes,

    just one thing.

    a)

    For FLT pin i want to have RED led to lit when there is a error, so i connect from 1v8 or 3v3  -> series resistor ( limit to 5mA) -> diode anode -> diode  cathode -> to FLT pin, and when FLT pulls low the LED will lit, is this correct?

    b)

    Regarding the  PGOOD, the PGOOD is initial LOW and when power good is reached then it will go high , so  at that point i wan to have green LED to lit, in order do drive this GREEN LED i need a N-mosfet that is turned on with PGOOD signal that has a pull-up , or can this bi done without mosfet?

    eg. connect the anode to PGOOD pin and add a 1k pullup to 3v3, and connect the cathode to gnd?

    Best Regards,

    David.

     

  • 0 in reply to d_zero
    TI__Guru** 105641 points

    Hi David,

    Both your circuits work, this is the way we used on EVM too. Please refer schematic in http://www.ti.com/lit/ug/slvua56/slvua56.pdf

    No need for any external MOSFET. 

    Best Regards,

    Rakesh