• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 46 subscribers
  • Views 104 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

ADS7953EVM-PDK: Manual Mode gets stuck reading back the same channel per the data header.

Gino Fumag
Prodigy 20 points
Part Number: ADS7953EVM-PDK
Other Parts Discussed in Thread: ADS7953, ADS7951

Tool/software:

I would like to run this in manual mode only, changing the channel I am reading in each new transaction. From the above plot you can see the SPI transactions are changing their channel each new transaction. The SPI clock has been tried at 10 and 1 MHz. This is being measured at the input of the dev board. I have an external supply for VBO=3.3V and VA_EXT=5V. 

My question is why in the above plots am I continuously getting back the same channel in the output data header(chan 5 in this plot but sometimes gets stuck on others). Is manual mode where every transactions is a new channel not a valid use case for this part and I would be forced to use one of the other auto modes?

Thank you!

  • 0
    TI__Genius 14790 points

    Hi Gino,

    Apologies for the delayed response on this issue. Can you clarify if you are using the ADS7953EVM-PDK evaluation board, or are you controlling the ADS7953 with your own controller?

    Is this happening consistently, or only occasionally? It seems like you are sending the correct command, and the SPI configuration itself also looks correct. There have occasionally been selection issues in manual mode, which is also why auto modes are encouraging. Have you found under which conditions this issue happens? Are you able to share the extended logic capture if it is available with data captured before this condition?

    Regards,
    Joel

  • 0 in reply to Joel Meraz
    Prodigy 20 points

    Hey Joel!

    No worries, thanks for getting back! 

    1. Yes ADS7953EVM-PDK evaluation board, however I am using my own module to communicate over spi, and providing an external source for digital and analog supplies. (have tried moving it around 5V for both and 5V=Analog and 3.3V=Digital).

    2. It is happening very consistently. It will gets stuck on a channel, but the channel it gets stuck on changes over time and is not consistent. I have gotten it to magically begin to work 2-3 times by messing with the supply, but that fix from day-to-day is not consistent (makin me feel crazy). 

    3. Yeah in our design case it is advantageous to not have registers that could be upset by radiation and continuously program exactly what we want - hence the manual mode. If there is any issues with selection in manual mode that seem consistent across parts (ADS7951 is our target) to please let me know now and I can try to pivot sooner rather than later. 

    5. Extended data capture is just more of the same really, nothing different - I can give you power on below:

    Zooming in a bit more it gets stuck on zero this time for the channel:

  • 0 in reply to Gino Fumag
    TI__Genius 14790 points

    Hi Gino,

    This seems to look like an issue with the specific device you are using. Do you have another device available, and are you able to swap this device with a working, known good device? This would confirm that the issue is with the device and not your sequence or other conditions like power. 

    Regards,
    Joel