nRF54 UART connection failure at low temperature

[Brutus]

Dear Nordic team,

We are using the nRF54L15 QFN52 package on our custom device and are using the P0.06 and P0.00 for the TX and RX, respectively, for our UART service interface. When testing our device in a climate chamber, we noticed that the UART connection was lost at around -18°C. As the operating temperature of the SoC goes down until -40°C, we didn't expect the UART to fail at -18°C. Would you have any clue to why this happened and how we can avoid it?

We submit a design review with our schematics. Case ID: 354184

Thank you in advance for your time and consideration.

Best regards,

Federico

[Turbo J]

Try to keep the HFXO on. Don't remember right now where the sample code for nrf_cock_control was.

HFINT tolerance is slightly too high for stable UART operation.

[Brutus]

Hi,

Thanks for the tip! will look at the sample code and try to tweak it to my needs