nrf52840 RF software calibration method

[liu hao]

I'm using nrf52840 for my product. when testing the Bluetooth RF of this chip, I found that the carrier is offset by 200kHz. i read many similar problems, it seems that the carrier offset of nrf's Bluetooth chip can't be adjusted by software, but I don't know if 52840 can?

If the 52840 can't adjust the carrier frequency offset through software, is it also impossible to adjust the carrier frequency offset in software for nrf's other low-power Bluetooth?

Thanks

[Jared]

Hi,

The offset can be adjusted by adjusting the load capacitors of the HFXO crystal. What is the internal load capacitance of your HFXO crystal and what is the size of the external parallel load capacitors?

regards

Jared

[liu hao]

Thank you. The external load capacitance of our product is 12pF, but where do I look for the internal load capacitance?

[Jared]

It should be specified in the datasheet for the crystal as CL