This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS54260: consuming more than 10mA when there is no load.

Part Number: TPS54260

Hi,

Here is our power tree for our project  

12V to 5V  TPS54260QDGQRQ1

5V to 3.3V TPS63000IDRCRQ1

5V to 3.8V TPS63020QDSJRQ1

When there is no load at 3.3V and 3.8V we are seeing a 13mA of current @ 12V input. We tried to load the 3.3V and 3.8V we are seeing the delta of 13mA always added wrt to the load current. And Please find the attached Schematic images below.

Are we missing something in our design ? Since ours is a batter powered device we are concerns about the sleep currents. 

Your advice at the earliest is highly appreciable. 

With Regards,

Akshay. 

  • Hi Akshay,

    Pls open SB45 and check what's the input current at 5V no load? 

    C77 should be placed to limit loop bandwidth, D48 and R134 should be connected to output 5V. 

  • Hi,

    After removing the SB45 We have given 12V input, current  consumption was 0.4mA and for 24V it was 0.55mA.

    C77 is placed, D48 and R134 are connected and taken the above readings.

    And, after connecting the SB45 we have opened the SB43, SB46 and isolated 3.3V, 3.8V from connecting to the load, overall current consumption from the 3 power ICs is 11.75mA.

    We also checked by directly giving the 5V input supply to both 3.3V and 3.8V converter ICs the current consumption was 11mA from only these two ICs TPS63020QDSJRQ1 (5 to 3.8V) and TPS63000IDRCRQ1 (5 to 3.3V).

    Awaiting for your early response

    Regards,

    Akshay

  • Hi Akshay,

    Based on your above testing result, the quiescent current is produced by U16 and U17.

    The PS/SYNC pin is pull high in your design which disable the Power Save Mode to improve efficiency at light load. Pls retest input current by short PS/SYNC pin to ground.