Low Freq = ?

[zhong0920]

Hi,

The device I am using is nRF52840, WLCSP package. Most of the analog IN pins are noted "low frequency I/O only", e.g. pins A5, A6, C7, C8. - I know there are some exceptions like C10.

The question is for those noted as "low frequency I/O only", how high a frequency/edge rate is considered unsuitable for them?

Best regards,

[Andreas]

Hi,

 

This has not been characterized too well, but the rule of thumb is <10 kHz and standard drive. Exceeding this at high drive will affect especially RX sensitivity if there is activity while the radio is enabled, how much we have not characterized but is probably something that will vary between designs also. Activity that exceeds the mentioned frequency/drive while the radio is disabled will not have any effect.

 

Best regards,

Andreas