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LP5907 QUIESCENT CURRENT

WhiteHorse
Genius 4430 points
Other Parts Discussed in Thread: LP5907

E2e,

Our customer has the following question concerning quiescent current for the LP5907.

We have 2 modes of circuit operations. They are:

1)Low-power mode

Vin=3.3v @ 1ma max

Vout=1.85v

 

2)High Power mode

Vin=5.5v @ 150ma max

Vout=1.85v

 

Questions. In low-power mode the quiescent current is too high at 425uA, (looking at 6.5 table). But it looks ok (11uA) if you look at Figure1. Can you clarify this?

  1. What would be the following in low-power operation over temperature?

 Vdrop-out ?

                Quiescent current ?

 

       2.  Is operating at Vin=5.5v ok for high-power mode

Thanks for your help.

Regards,

John Wiemeyer

  • 0
    TI__Mastermind 22610 points

     Q1a : Vdrop-out ?

    A1a :Estimated to be 1mV(max)

    Q1b: Quiescent current ?

    A1b: Estimated to be 27uA(max) (Edit : should be 212uA(max) see correction below)

    Q2: Is operating at Vin=5.5V ok?

    A2: As long as device dissipation of 547 mW and Theta(ja) does not push the junction temperature too high, no problem.

    (Edit... to prevent possible confusion the 'Iq vs Iout' chart has been removed ... see new chart below)

     

  • 0
    TI__Mastermind 22610 points

     

    My apologies, but I need to make a correction to my my reply to the Quiescent current question.

    In my haste presumed that the que current slope is linear across the load current range. 

    It is NOT. The Iout=0mA is a unique case.

    Limited bench testing has confirmed the knee is where Iout is approx 1mA.

    As such I have revised my estimated max Quiescent current at Iout=1mA to be 212uA(max).