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TPS3808: power consumption

Fernando Alcaide
Prodigy 120 points
Part Number: TPS3808


Dear, I have one doubt about maximum consumption of this device. 

In page 6 of datasheet appear the Idd max. is 6uA. But MRz pin has a pull up of 90k. In this case, the total power consumption when MRz is not active, it  shall be : 6uA+ 3,3V/90k= 44.6uA.  is it true?

Thank you in advance. 

  • 0
    TI__Mastermind 35210 points

    Please see the conditions specified (below). The max iQ would be determined under worst-case conditions, with the manual reset open.

    To avoid a large in efficency figure, the amount of time MR should be assert low should be minimized. The detection scheme is only by level rather than time, so if the MR pin see a voltage below the threshold, the RESET will trigger.

  • 0 in reply to Marshall_Beck
    Prodigy 120 points

    Thank you for your answer.

    But in the case "RESET not asserted MR", the MR input is internally tied to Vdd by a 90 kohms pull up resistor. In this case power consumption shall be (3,3v/90k)+ 6uA=

    uA. Is it true?

    According I understand, this is:

    MR Reset power consumption
    open circuit 1 6uA+ 3,3/90k(due intenal pull up tied to Vdd)
    0 0 6uA.

    Thank you in advance

  • 0 in reply to Fernando Alcaide
    TI__Mastermind 35210 points
    For the case of MR = Open, Reset = 1, yes the MR is pulled up internally to VDD, though VDD is not across the pull-up. The combination of the internal pull-up and the high-Z, CMOS input that the pull-up is tied to, results in minimal current flow that is taken to in account for in the datasheet specification.