• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 51 subscribers
  • Views 183 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.

CC2640R2L: Disabling 32-kHz clock increases power draw

Edward Swanson
Prodigy 20 points
Part Number: CC2640R2L


Hello, I am attempting to disable the 32-kHz clock on my CC2640R2L since we do not routinely make BLE connections and we only beacon every 5 seconds. According to swra499c, our current consumption should go down. Instead, our power draw goes up 7 uA (from a baseline of 6 uA). I believe the culprit may be the RCOSC calibration. Is there any way to reduce our current consumption while still calibrating so we stay within the specification?

Here is an example of our power.

Thank you,

Ed

  • +1
    TI__Guru** 101460 points

    Hi Ed,

    Thank you for reaching out.

    I confirm, if you are only using beacon mode, crystal calibration should be disabled. Please note that in general, the contrary is true (i.e. we ask users to enable calibration when using 32kHz-crystalless mode).

    If not already done, I recommend you review the User's Guide. There you will find the code we suggest modifying in order to enable the calibration. Follow the same in order to disable it.

    Please let me know if you need more guidance.

    Best regards,

  • 0 in reply to Clément
    Prodigy 20 points

    Hi Clément, thank you for your answer.

    If I turn off the calibration our performance greatly improves. I have two follow up questions.

    1. Would you expect us to still be able to make 1 connection once every few weeks/months if we never enable RSOCS calibration?

    2. Our power consumption matches what we have with the crystal enabled. swra499c  mentions that our current usage could go down without the crystal. Do you have any experience with how much it could decrease and what you would have to do? The user guide doesn't seem to mention that.

    Thanks again,

    Ed

  • 0 in reply to Edward Swanson
    TI__Guru** 101460 points

    Hi,

    1. I don't think a Bluetooth LE connection could reliably when using the 32kHz-crystalless mode

    2. The power consumption should be reduced by the power consumption of the crystal. The actual number depends on the selected crystal and design.

    I hope this will help,

    Best regards,