https://devzone.nordicsemi.com/f/nordic-q-a/72139/spim-current-on-hfxo-hfintWhile digging for electrical information I came across : .63ma using HFINT or 1.58ma using HFXO ? So I hunted down HFXO to see how to switch between them: But nothing about selecting HFINT. I found The HFINT source will be used when HFCLKen-USTelligent Community 13Mon, 01 Mar 2021 12:39:10 GMThttps://devzone.nordicsemi.com/thread/296835?ContentTypeID=1Mon, 01 Mar 2021 12:39:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1cd36459-2071-4af9-a5df-9fda89a8a40eH&#229;kon Alseth<p>Hi,</p> <p>&nbsp;</p> [quote user=""]So I hunted down HFXO to see how to switch between them:[/quote] <p>This is the external HFXO configuration. By default, you run on HFINT source, which is a RC oscillator:</p> <p><a href="https://infocenter.nordicsemi.com/topic/ps_nrf9160/clock.html?cp=2_0_0_4_2_1_0_17#register.HFCLKSTAT">https://infocenter.nordicsemi.com/topic/ps_nrf9160/clock.html?cp=2_0_0_4_2_1_0_17#register.HFCLKSTAT</a></p> <p>&nbsp;</p> <p>To switch to using HFXO instead of HFINT, you can run the TASKS_HFCLKSTART (or use an appropriate clock driver that calls the task).&nbsp;</p> <p>The overall logic is similar to how it works on the nRF5-series devices, but you have a TCXO, as required for keeping 3gpp timing.</p> <p>&nbsp;</p> <p>Kind regards,</p> <p>Håkon</p><div style="clear:both;"></div>