How to use LFXO and HFXO efficiently in custom nRF54L15 Board.

[Aman711]

Hi Team,

I need to use this external clock for my deep sleep use case so let me know the step forward for the same.

I am using custom board with nRF54L15 and also LXFO and HFXO included.

[Benjamin]

Hi Aman,
Thanks for reaching out. Could you please expand on your issue? Have you already attempted any clock configuration, or are you starting from scratch?

Best regards,
Benjamin

[Aman711]

Hi Benjamin,

I have a custom board with both the external crystals and found that once i enable it I did found the issue with sensors. I have tried different configurations but could not able to get the success.

Let me know how to use those external clocks efficiently for deep sleep feature.

Thank you for your time.

[Benjamin]

Hi,

Are you referring to timed wakeup from System OFF?

If you want to use the GRTC SYSCOUNTER compare event to wake the device from System OFF, an external 32.768 kHz crystal must be connected to the XL1/XL2 pins. Without the external crystal, timed wakeup from System OFF is not supported on nRF54L15.

You will, for example, need the following Kconfig symbols:

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=n
CONFIG_CLOCK_CONTROL_NRF_K32SRC_XTAL=y

Regarding the sensor issues, could you provide more details about what you are seeing, including any logs or error messages, configuration, the sensor setup you are using, and what you have already tried? That will help us narrow down the issue.

Best regards,
Benjamin