https://devzone.nordicsemi.com/f/nordic-q-a/81815/about-nrf52840dk-1-8v-outputHello. I am developing with nRF52840DK. Normally, I think that the buck regulator supplys 3.0V to Interface MCU and nRF52840. I want to connect the 1.8V peripheral to nRF52840D K under the &quot;nRF OnlyMode&quot;. Re-download will be processed underen-USTelligent Community 13Wed, 17 Nov 2021 12:18:46 GMThttps://devzone.nordicsemi.com/thread/339421?ContentTypeID=1Wed, 17 Nov 2021 12:18:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a583bd56-3c5f-4c36-b591-071f98791357Vidar Berg<p>Hello,</p> <p>The nRF52840 will still get supplied with 3V with SW6 set in the &quot;<span>nRF OnlyMode</span>&quot;. The easiest way to get 1.8V on VDD is to use the nRF USB as the power source which you achieve by setting nRF power source switch to &quot;USB&quot; and plug in another USB cable on the nRF USB Port.</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1637151321075v1.png" alt=" " /></p> <p>Also note that you can use the <span><a title="REGOUT0" href="https://infocenter.nordicsemi.com/topic/ps_nrf52840/uicr.html?cp=4_0_0_3_4_0_7#register.REGOUT0">REGOUT0</a></span> register to change the default voltage.</p> <p>Best regards,</p> <p>Vidar</p><div style="clear:both;"></div>