RTOS/CC2650: cc2650 End Device TI-RTOS RF Frequency tune

Spiros Kleftogiannis

Part Number: CC2650
Other Parts Discussed in Thread: CC2530

Tool/software: TI-RTOS

Hello,

I am using cc2650 as a Zigbee End-Device based on simplelink SampleSwitch.

When flashing the same project in different custom PCBs produced in the same lot, using maximum available Tx Power, I am seeing that 40% of them have very low LQI and their communication range is below 5 meters where the other 60% of lot can go up to 30 meters without any problems.

Using spectrum analyser I saw that the output frequency of the "bad" PCBs are about 25 ~ 50KHz next to the center channel frequency.

My question is: Is there a way to tune the output frequency in TI-RTOS? In cc2530/31 there is FREQTUNE register that can be modified, but in cc2650 I couldn't find somthing (not even in Smart RF Studio).

Thank you in advance,

Spyros

over 8 years ago

0 Fredrik K over 8 years ago

TI__Guru** 106705 points

Hi Spyros,

The RF frequency is set by the 24 MHz crystal which again is set by adjusting the load capacitors to the correct value for the crystal you are using. In the CC2650 the load capacitors are internal and adjust through CCFG. More details can be found here: processors.wiki.ti.com/.../CC13xx_CC26xx_Crystal_Tuning

Cheers,
Fredrik

0 Spiros Kleftogiannis over 8 years ago in reply to Fredrik K

Prodigy 130 points

Thank you Fredrik, I will try that in my project.

Also, do you know how can this be set in Smart RF Studio 7 in order to perform my tests there?

Best,
Spyros

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RTOS/CC2650: cc2650 End Device TI-RTOS RF Frequency tune