nRF52840 Frequency tolerance

[UBAN]

Hi,

nRF52840_PS has the following parameters.

Could you tell me why ±30ppm?

If it is ±40ppm, it can be understood as Bluetooth low energy spec..
https://devzone.nordicsemi.com/f/nordic-q-a/14478/nrf52832-frequency-tolerance-bluetooth

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Symbol                         Description                                                                                                                                         Max.

fTOL_HFXO_BLE_LP  Frequency tolerance requirement, Bluetooth low energy applications, packet length > 200 bytes   ±30ppm

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Best regards,

uba

[Håkon Alseth]

Hi,

 

If a packet is >200 bytes (ie: longer time in TX and RX mode), the accumulated drift will be worse in case the transmitter and receiver are drifting in opposite directions.

This is listed to ensure devices are sending/receiving properly, and to operate within all other RF PHY related specifications given in the product spec. Note that for packets less than 200 bytes, the requirement is <=40 ppm:

https://infocenter.nordicsemi.com/topic/ps_nrf52840/clock.html?cp=3_0_0_4_3_3#unique_1001605180

 

Kind regards,

Håkon

[UBAN]

Thank you very much.