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TMS320F28335: Where / how to get previous product change notices

Part Number: TMS320F28335

Hello, I'm looking for PCNs regarding this DSP. I have some devices with different lot codes that aren't acting in the same manner. We'd like to trace to a possible change in location. 

Part number is TMS320F28335PGFA

Known good device is coded "CA-16AJKTW"

Marginal device is coded "C A-04C05FW"  

Thanks

  • Tim,

        I will look into the PCN, but could you explain exactly what the issue is?

  • TI does not have publicly available change history for all devices. PCN information is only sent to customers who are actively purchasing material at the time of the change.  

    We checked the LTCs and found there have been no changes that would impact device performance or cause shifts in performance at any particular timeframe. Both batches were built at the same manufacturing locations albeit ~1yr apart in time, which rules out any change in location as you mention.

  • Hi Hareesh, we're investigating why some (but not all) newer DSPs in our system behave differently between a FlashErase -> FlashProgram ->Reset sequence and FlashErase -> FlashProgram ->PowerOff -> PowerOn sequence. It appears as a calculation error. 

    The older DSP is more than one year old -- this product started production in 2012.  

    BR, Tim

  • Sorry I don’t understand what exactly the problem is. When you say “calculation error” are you referring to some computation error by the DSP? 

    Did you try a A-B swap? i.e. move the suspect device to a known good board and move the device from the known good board to the problematic board to see if the problem follows the device? 

    Did anything else change in your board (or the setup)? For example, any other component (or even a component vendor), any other part substitutions or even the PC used to program the DSP?

  • Hi Hareesh, we are investigating either a filter or correlation algorithm error. We are having a difficult effort determining where the algorithm fails as the original designers are no longer with the company. 

    We did the A-B swap using the above date-codes. The problem follows the programmed DSP. 

    Many components have changed on this board over the past 8 years. That's why I was hoping for PCNs; these might help in narrowing down which circuits to investigate.  

    BR, Tim

  • How many devices are showing this failure? Out of how many? Can you provide the DPPM value? Are all failing devices from the same date code? 

    This is a very mature device that we have shipped millions over the last 15 years.