https://devzone.nordicsemi.com/f/nordic-q-a/35331/nrf51-uart-power-consumptionHi, 1-I did some test for nrf51422 (SDK12.3 + soft device S130) power consumption. result as below: -system on sleep mode( without UART and BLE Advertise ):90uA -system on sleep mode(with active UART and BLE Advertise ):1.1mA UART module currenten-USTelligent Community 13Tue, 12 Jun 2018 12:14:53 GMThttps://devzone.nordicsemi.com/thread/135739?ContentTypeID=1Tue, 12 Jun 2018 12:14:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7f3a3a0b-29cf-4102-8b0e-30d766ca4662Kenneth<p>Hi,</p> <p>You are right that the UART peripheral require 220uA, however the UART peripheral rely on some block resources, which may add to the system current consumption.</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-359aca494a8e44f4861d0590b49b44ae/pastedimage1528805138771v1.png" alt=" " /></p> <p>Regarding reducing power consumption maybe this thread may be useful:<br /><a href="https://devzone.nordicsemi.com/f/nordic-q-a/34692/low-power-uart-migration">https://devzone.nordicsemi.com/f/nordic-q-a/34692/low-power-uart-migration</a>&nbsp;</p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>