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.

LMR10515: Out voltage is not stable

Part Number: LMR10515

I'm using LMR10515Y.  It has a regulated 5.0V input and is setup for 3.3V output.  The nominal current draw is around 400mA.  Cin and Cout are 22uF ceramic.  Inductor is 2.7uH.  Most of the time the output is stable.  On occasion at power up, the output will have a very fast dip to below 2V.  This repeats every 760mS.  This will cause the microcontroller to keep resetting.  

  • Hi Steve,

    Thanks for your question.

    I am not sure whether I have understood correctly.

    From my understanding, the converter is on and the output voltage is regulated (IOUT ~ few mA). Then you switch ON the MCU (IOUT ~ 400mA) and you see the voltage dip.

    Is this correct?

    Please send me  the waveforms of VIN and VOUT when this glitch happens; one acquisition with an high time scale per division (maybe 1ms), and another one zoomed on the glitch (for this second one please insert also the SW node).

    Thanks,

    Stefano

    All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml).