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TPS63051: TPS63051 draws additional 3mA from battery

Rich Obermeyer
Prodigy 30 points
Part Number: TPS63051


TPS63051 draws additional 3mA from battery.

Does a resistor have to pull up PG if PG is not used?

  • 0
    Prodigy 30 points

    Not that I got any help or even a reply yet.

    Changing the PWM pin from high to low reduces the current by 3mA.

    Without the pin low the regulator efficiency is terrible at low current because of excess current draw from somewhere.

    Not that the block diagram or documentation show how that is possible. 

    Did I miss that on the spec sheet?

    So why not make PWM low always?

  • 0 in reply to Rich Obermeyer
    TI__Expert 5425 points
    If you do not want to use PG you don't need to connect the pull up resistor.

    TPS63051 has a built in feature which is called power save mode. You can find a detailed description in the datasheet section 8.4.2.
    I think the experiments you did basically confirm that it is working properly. The application curves (Figure 10 and 11) show how it is affecting the efficiency of the converter.
  • 0 in reply to Juergen
    Prodigy 30 points

    I guess our definition of working properly are way different.  The part bleeds 3mA additional current if the part is not set for low power mode.

    I did not see anything alarming in the data sheet to indicate the part wastes 3mA if not set for low power mode.

    The quiescent says 45uA in non low power mode.  How do I get to the 45uA in non low power mode?

    Clearly looks like a bug to me or at least deserves some additional documentation to explain the "non low power" mode bleeds 3mA.

  • 0 in reply to Rich Obermeyer
    TI__Expert 5425 points

    Quiescent current is not meant to be the no load input current. You can find a very detailed description in the application note which is listed in the related technical documents in the product folder of the device. Here is the direct link to the file: http://www.ti.com/lit/pdf/slyt412