CC2340R5: how to adjust the HF Oscillator

robin Moon

Expert 1510 points

Other Parts Discussed in Thread: CC2340R5, SYSCONFIG

Tool/software:

Hi experts,

I would like to modify the HF oscillator load capacitor value of CC2340R5.

I found the related guide document as below. but there is no data on cc2340R5.

CC13xx/CC26xx Hardware Configuration and PCB Design Considerations (Rev. H)

https://e2e.ti.com/support/wireless-connectivity/bluetooth-group/bluetooth/f/bluetooth-forum/1215862/cc2340r5-crystal-tuning/4589715?tisearch=e2e-sitesearch&keymatch=cc2340%252520tuning#4589715

please let me know how to adjust the HF oscillator load cap.

thanks

over 1 year ago

0 Jan over 1 year ago

TI__Mastermind 42100 points

Hi,

The HFXT may be adjusted/compensated through the Device Configuration module in SysConfig through the RF Temperature Compensation tab:

Best Regards,

Jan

0 robin Moon over 1 year ago in reply to Jan

Expert 1510 points

Hi Jan.

I need an explanation of HFXT Compensation Threshold and delta values.

please provide a list of measured cap-array delta values as below in chapter 6.4 of below.

CC13xx/CC26xx Hardware Configuration and PCB Design Considerations (Rev. H)

thanks

0 Jan over 1 year ago in reply to robin Moon

TI__Mastermind 42100 points

Hi,

With regards to the cap array values, these should be found experimentally and the ideal value will depend on your board design. I would suggest using SmartRF Studio to tune the trims until you see the desired performance and then using the settings found in SmartRF Studio.

For the RF Temperature compensation, you will follow a similar process. We do not have a similar application report for the CC23XX at this time, so the best way would be to modify these experimentally. That said, the default values tend to work well.

Best Regards,

Jan

0 robin Moon over 1 year ago in reply to Jan

Expert 1510 points

hi Jan.

The document below says that the cap-array can be adjusted through CCFG, please let me know how to adjust the cap-arry value in CCFG.

https://www.ti.com/lit/an/swra495k/swra495k.pdf

thanks

regards,

0 Jan over 1 year ago in reply to robin Moon

TI__Mastermind 42100 points

Hi,

The CCFG is configured automatically through the auto-generated files provided by Sysconfig. Using the options I had mentioned earlier will set the CCFG to the appropriate values.

Best Regards,

Jan

0 robin Moon over 1 year ago in reply to Jan

Expert 1510 points

Hi Jan.

When HFXT cap-array tuning, is there a factor and measurement table that determines Q1/Q2?

a load capacitance of external oscillator is 7Fp in custom board.

If the load cap is not connected, the BLE connection will not be connected. The Q1/Q2 value of the load cap 7pF is required.

thanks

0 Jan over 1 year ago in reply to robin Moon

TI__Mastermind 42100 points

Hi,

If I am not mistaken the ideal Q1/Q2 values should be found experimentally for a given board design until the desired performance is observed.

Best Regards,

Jan

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CC2340R5: how to adjust the HF Oscillator