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.

TM4C123BE6PZ: TM4C123 with abnormal VDDC(1.5V)

Part Number: TM4C123BE6PZ

Hi Champs,

My customer is using TM4C123BE6PZ in their products. Recently they found several board cannot start up, on which the VDDC is about 1.5V, exceeded 1.32V. And VDD is still 3.3V. Looks the internal LDO is damaged. The failure board cannot be downloaded. So is there any possibility can cause VDDC abnormal?




  • Have you/they checked that the number, value & (close) placement of VDDC's (required) capacitors are correct?

    It would be useful to know the approximate percentage of total board failures - exhibiting this excessive VDDC voltage...
  • Hi,

    Please find the capacitors connected to VDDC. I think it is OK.

    What I am thinking is maybe the internal damage is caused by ESD. I will do FA to find any phasical demage.



  • Hello Young

    Please ask the customer to share their board schematics for reviewing the power connections.
  • Thank you - you've supplied most of that requested.    The "percentage" of failures would prove of value/interest.

    Your values appear proper - is it possible that cap(s) are defective - or mismarked?    Caps should be as close as possible to the MCU.

    Perhaps the "best test" results from your "Swapping" all caps between a "failed" and "working" board.   Such should (quickly) reveal IC vs. component problem!