nRF9160 LFXO/HFXO : Clarification on nRF9160 Clock Sources and Precision Timing

[IMS]

Hello,

I am using the LTE IoT 4 Click board based on the nRF9160, with SDK version 2.6.0 and modem firmware version 1.3.6. I read in the documentation that the nRF9160 provides four clock sources: HFINT, HFXO, LFRC, and LFXO.

I understand that HFINT and LFRC are integrated within the SiP. However, I am having trouble determining whether LFXO and HFXO are also integrated or if they require an external oscillator to be connected for use.

My goal is to achieve the highest possible timing precision. The idea is to synchronize the SiP’s clock with the network clock while minimizing drift, so that the system clock can continue counting from the synchronized network time without requiring frequent resynchronization (e.g., every minute) to maintain minimal drift.

Could you clarify whether external oscillators are necessary for LFXO and HFXO, and what the best approach would be for achieving a highly accurate system clock?

Thank you in advance for your support.

Best regards,
Ibrahim

[Jared]

Hi,

The crystals are already included in the SiP internally so no external components needed except for decoupling capacitors, antenna tuning components + antenna.

My goal is to achieve the highest possible timing precision. The idea is to synchronize the SiP’s clock with the network clock while minimizing drift, so that the system clock can continue counting from the synchronized network time without requiring frequent resynchronization (e.g., every minute) to maintain minimal drift.

Are you going to use the GPS on the nRF9160?

regards

Jared