• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 51 subscribers
  • Views 425 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.

PAN1720/PAN1721 32.768kHz crystal accuracy

Matthias Mueller
Intellectual 380 points

Hello everybody

Has anyone some information about the 31.768kHz crystal accuracy of Panasonics PAN1720/21 modules? Frequency tolerance as well as frequency versus temperature would be very interesting.

I figured, it would be much faster if I ask in this forum first, because Panasonics response time is awfully slow :(


Thank you very much in advance

Matthias

  • 0
    TI__Guru 57865 points
    Hey Matthias,
    I suppose you mean 32.678 kHz. The accuracy should be at least +/-500 ppm to be Bluetooth low energy compliant although I do not know if it's more accurate than that. I could not find any public info at least. Is there any specific reason you want to know the accuracy?

    Best Regards
    Joakim
  • 0 in reply to J Lindh
    Intellectual 380 points
    Hi Joakim

    Thank you for the fast replay.
    The reason I want to know this is to set the correct accuracy via the HCI_EXT_SetSCACmd command. I think this would optimize the current consumption.
    In my application I discovered, that the BT sometimes (~4x a day) looses the connection, if the peripheral is around and below 0°C (the central is indoor). Due to the fact that everything works perfectly if the peripheral is also indoors, I assume that the crystal has a low tolerance and therefore will drift too much. I use a very high slave latency, a big drift would cause such a behaviour. The used battery is fine and provides enough power in those conditions.
    It would be nice to know the correct ppm-value to set it via the command above. To just set it to 500ppm by default would increase the current consumption unnecessary.

    Best Regards
    Matthias
  • 0 in reply to Matthias Mueller
    TI__Guru 57865 points
    Hey Matthis,
    I understand. We usually do HW reviews for our module providers although I can't find any reference internally so maybe they did not take that offer. I hope you'll get your answer soon, either through Panasonic (Feel free to share the information if so) or maybe some other fellow around this forum.

    Best Regards
    Joakim