NRF5340 LFCLK RC or LFSYNT

[tcube]

Hello,

We are making a custom board with the NRF5340. There is no external crystal for the 32kHz.

What is the best option between internal RC and LFSYNT as 32kHz source and how to configure the project ?

Thanks,

[Asbjørn]

Hi Thomas,

The LFSYNT is being generated from the HFCLK directly, so it will be accurate as the HFCLK source, but also require the HFCLK source to be running with the power consumption that involves. The LFRC is generate from its own circuitry, so much lower power consumption, but up to 250ppm in accuracy with calibration. It's all a trade off for your application on power consumption, start up time and accuracy. I'd recommend to have a look at the LFCLK chapter in the nRF5340 product specification. https://docs.nordicsemi.com/bundle/ps_nrf5340/page/keyfeatures_html5.html

Best regards

Asbjørn