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TMS320DM368: Boot Issues at Cold Temperature (-20C to -40C)

Part Number: TMS320DM368

We have been using the TMS320DM368ZCED in one of our products for the past 8 years. We run an Environmental Screening Test on each unit which brings the unit down to -40C, soaks for an hour, then powers up for a quick test. Recently, we have been experiencing booting issues at temperatures ranging from -20C to -40C on 13% (8 of 60) of our production boards. At these cold temperatures, the processor fails to load the UBL from NAND and aborts.

In our debugging, we’ve replaced multiple NAND IC’s and experienced no changes (i.e. failures at the same temperature). We also verified that the power supplies function normally during failed boots and X-Rayed the parts to ensure that there were no issues with the soldering. We have only experienced a change in result when we replaced the TMS320DM368ZCED processor on a failing board. We had a board that failed to boot at -20.3C. After we replaced the processor, the same board with a new processor booted at temperatures down to -36.2C (as close to -40C as our chamber would go). We are not 100% sure that the processor is causing the failure to boot at cold, but based on the result from replacing the processor it does seem likely.

Have anyone seen issues with this processor at cold temperatures before? Are the lots are tested at the rated temperature ranges (-40C to 85C)? Or are they designed to meet?

We really appreciate any help regarding this issue. Thanks!


  • Hi,

      Is it possible for you to also swap the chip from the bad board to a good known board? Will it still fail to boot below -20.3C?

      In the meantime, can you please show the device marking on the 8 chips that you believe are having issue to boot up at cold temp?

  • Hi Chris,

    So far, we've only replaced the processor on boards that fail. We'd be open to trying other tests, though there is some risk each time we remove and re-solder the processors on the boards. 

    Here are the device markings of the boards with issues at cold temp:

    TC00011 - 2AA6ZZW
    TC00018 - 2AA6ZZW
    TC00040 - 2ACDFJW
    TC00053 - 2ACDFJW
    TC00056 - 2AA709W
    TC00063 - 2AA709W
    TC00070 - 2ACDFJW
    TC00074 - 2ACDFJW

    Also attached are pictures of the processors:



  • Hi Justin,

      We will check internally and get back with you. 

  • Hi Justin,

    We search our database and below are the information. 

    We shipped some material with similar symbolization back in 2012.
    We cannot comment on whether the material you are using is that material or of some other/non-TI origin.
    We do not provide analysis or debug support of material unknown origin or of that age.

     Will you be able to confirm if these are genuine TI parts with certificate of authenticity?

      If you feel like discussing offline, you can PM me. However, I will be out of office the first few days of next week. Please expect delay in my response. 

  • Hi Chris,

    Thank you for the response. I reached out to our production with your questions. Hope to hear from them soon.