High frequency signal on a low frequency GPIO

[AvihayZ]

Hi,

I am using P0.10 GPIO of nRF52840 (QFN package) as an output for driving a transmission circuit with an 8MHz digital signal.

According to the datasheet this pin is defined as a low frequency I/O only which does not support high-drive mode.

However in practice the signal looks steady and stable regardless the 10kHz constraint mentioned in the document.

In addition, I also tried to configure this pin to high-drive mode and indeed I saw a difference in the signal shape.

Can I rely on this behavior of P0.10?

Pictures from page 577, nRF52840_PS_v1.1:

Thanks in advance,

Avihay

[Andreas]

Hi,

 

The IO-driven signal is fine, but using these pins while the radio is active can affect select radio performance parametres, e.g. TX modulation characteristics and RX sensitivity.

 

Best regards,

Andreas