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Original question:

CC3220R: What is CC3220 tx power and sensitivity accuracy?

CC3220R: Is there place to save tx power setting and it cannot be clean even erase fw?

Frank(EP) Liu
Expert 4415 points
Part Number: CC3220R

Tool/software:

Hi,

My customer wants to do tx power calibration.

They want to know a better way to save the calibration data in CC3220R. 

So, they can use one fw and save the tx power in CC3220R. When CC3220R power up, the fw can read the data and set the tx power.

Due to the calibration data for tx power is different with the board, they want to keep this data with cc3220R iC even they erase and upgrade fw to external flash.

Is that possible?

BR,

frank

  • 0
    TI__Intellectual 2460 points

    Hi Frank,

    In the CC32xx, there are different calibration modes which optimize the power consumption and when calibration is performed based on the use case.

    Here is the description from the NWP user's guide:

    • Normal calibration mode is used to achieve the best RF performance, or when the environment of the device is prone to changes (temperature changes).
    • Triggered calibration mode is used for lowest power consumption. Calibrations are done once on the first boot, and kept for consecutive boots. Recalibration is done on TX power change, or during the restore-tofactory process. Triggered mode can issue calibrations when updating to a new service pack that includes radio changes, after any TX power level change, or if the calibration file in the serial flash is corrupted.
    • One-time calibration mode is similar to Triggered mode, but recalibration is never done under any circumstances. One-time is used when the system power source is not able to handle the peak calibration current. In this mode, user actions that trigger recalibration in Triggered mode are blocked.

    You are probably looking for the one-time calibration mode, or triggered mode.

    Please see the NWP user's guide: https://www.ti.com/lit/ug/swru455m/swru455m.pdf

    Regards,

    Jonathan 

  • 0 in reply to Jonathan Cohen
    TI__Expert 4415 points

    Jonathan,

    customer wants the system tx power with accuracy in +/-1dBm (not only ic). So, IC automatically calibration can do this?

    if no, customer would do system calibration. They would measure the tx power from system, save the offset from target power, cc3220r can set tx power at power up.

    so, customer wants to know if there is memory in cc3220r to store this value.

    BR,

    frank

     

  • 0 in reply to Frank(EP) Liu
    Guru 78115 points

    Hi frank,

    I think requirements of your client not make much sense from practical stand point. Only exception can be if their application have some strict SAR requirements. When is set proper country mode, device will meet required TX power according to regulatory table. If your customer want do such precision calibration, conductive measurement will not do good job (it cannot eliminate antenna variance). It will be needed to do wireless calibration inside anechoic chamber. Such approach will be extremely expensive.

    No. TX calibration by NWP itself will not eliminate different RF property of antenna PCB path and antenna itself. It can eliminate variance of TX power due to temperature change.

    If your customer want to persist own data (calibration data) after erasing of sFlash, there is no other option then adding another storage for own data (e.g. small EEPROM). There may to be some other possibility, but your customer will need to do own research. Because this way is not supported by TI. In case of Vendor Device Authentication is not used he can use OTP part of sFlash (if feature is supported by flash chip). But it will need to use direct access into sFlash from host MCU. This is technically possible, but not supported by TI. This will be up to your customer only.

    Jan