nRF52840 low frequency pins

[rikhard]

Hi

I would like to understand more thoroughly why nRF52840 LF GPIO pins might couple noise to radio subsystem if driven with too high frequency operation? Does the GPIO LF subsystem share same powering(?) block with radio, or are the internally just close to each other and therefore the noise gets coupled to radio? Is this particulary RX issue or does this also inflict problems to TX?

Any more detailed reason is very much appreciated!

Thanks

[Priyanka]

Hi Riku,

Yes, the LF GPIO pins are quite in proximity with the radio and hence can cause interference while transmission/reception. So, they are generally not recommended to be used for high frequency operation, even though they are not limited to low frequency. In case you are not planning to use the radio during the I/O operation, you can use them, but we would normally suggest using the other GPIO pins.

Best Regards,

Priyanka