• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 54 subscribers
  • Views 139 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

CC1354P10: Crystal vs RF Performance How to measure? CC1354

Bhautik Ramoliya
Prodigy 100 points
Part Number: CC1354P10
Other Parts Discussed in Thread: CC1190,

Hi there,

   In our custom design based on CC1354P10RGZ, we are using this crystal with external load capacitor mounted, and it's properties are well within the other similar crystal which TI suggest.

   So i would like to know - 

  1. Does above crystal fine to use? as long as it is matching the design/layout rules ?
  2. We see that CC1352P10RGZ works fine (except the RF), On RF still we in Testing mode as we use it with External PA CC1190, but i would like to know do we required to disable internal load capacitance? (if yes then how do that in Smart RF Studio?)
  3. Generically i would like to know the performance of the RF vs crystal used? (let's say if  tolerance is bad or due to pcb/design issue crystal's performance is bad), in this situation , will output of RF(SubGHZ or 2.4Ghz)  will be totally off? or it will be degraded. Ex. If we set transmit power to 5dbm and can get around 0 dbm signal because of crystal's behavior?

Regards,
The Mat

  • +1
    TI__Genius 12285 points

    Hi Bhautik,

    1. We also provided a list of recommended 48 MHz crystals over email for reference. If you wish to use the crystal you linked, you can use the following App Note as a reference guide for selecting a crystal (details are given on the different parameters to consider):

    I would ideally need to see the specific crystal datasheet to be able to check the suitability of the part as the parameters available in the linked datasheet are for the entire vendor series.

    Are you able to request this from the manufacturer? For example, the operating temperature ranges are not specific (so I cannot comment on this).

    You can send this via email if the manufacturer would not wish for this to be shared on a public forum.

    2. As you are using the CC1190 with the Sub-1 GHz path of the CC1354P10 (not the +20 dBm HPA path), you can disable the internal load-capacitance. This is toggled using the following button in SmartRF Studio:

    It can be turned off by default if the Enable high output power PA setting is turned off, but is not required (you can use the internal capacitor array if needed).

    Information about this can be found in Section 3 (particularly 3.1.1) of:

    3. The first factors to check when encountering TX Output Power issues is the matching network and/or the RF settings. Crystal tolerances (and the accompanying frequency offsets) can affect the required RX Bandwidth, with an accompanying degredation of the noise floor and, ultimately, RX Sensitivity.

    More information about this is given in the following App Note (the fundmental theory is also applicable to the CC13x4 devices):

    Regards,

    Zack