https://devzone.nordicsemi.com/f/nordic-q-a/62713/nrf52840-inbult-rtc-is-there-are-need-to-provide-external-rtcHello, nRF52840 is having the inbulit RTC for keeping the time. Should i need to use external RTC with coin battery for even after power off the BLE nRF52840. PLease provide the connections for external RTC with nRF52840 Soc Thanks Baluen-USTelligent Community 13Wed, 17 Jun 2020 14:55:45 GMThttps://devzone.nordicsemi.com/thread/255589?ContentTypeID=1Wed, 17 Jun 2020 14:55:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7391aba8-e22f-45a2-935e-01761c47c346J&#248;rgen Holmefjord<p>Hi,</p> <p>The RTC in the nRF52 series ICs is not a Real-Time <strong>Clock</strong> and it is not intended to keep time, it is a low-power timer named Real-Time <strong>Counter</strong>. If you want to keep track of time when the chip is in system OFF mode, or power is cut, you need to add an external Real-Time Clock to your design.</p> <p>Best regards,<br />Jørgen</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/255525?ContentTypeID=1Wed, 17 Jun 2020 12:09:38 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b8c4e8ce-ab3f-4286-a9fd-f6f5b253727bawneil<p>It&#39;s up to <strong>you</strong> to evaluate whether the inbuilt RTC meets <em><strong>your</strong> </em>specific requirements and constraints!</p> [quote userid="90993" url="~/f/nordic-q-a/62713/nrf52840-inbult-rtc-is-there-are-need-to-provide-external-rtc"]PLease provide the connections for external RTC[/quote] <p>That will depend on the RTC <em><strong>you</strong></em> choose!</p> <p>Quite likely, it will be I2C - maybe plus a couple of connections for alarms, etc&nbsp; ...</p><div style="clear:both;"></div>