https://devzone.nordicsemi.com/f/nordic-q-a/112263/startup-problems-at-low-battery-voltage-with-nrf52811Hello, I am using the nRF52811 on a keyfob that transmits short packets when a button is pressed. The button directly connects power to the MCU, and the firmware immediately enters the main thread&#39;s infinite loop to start transmitting periodically.en-USTelligent Community 13Thu, 20 Jun 2024 13:43:14 GMThttps://devzone.nordicsemi.com/thread/489781?ContentTypeID=1Thu, 20 Jun 2024 13:43:14 GMT137ad170-7792-4731-bb38-c0d22fbe4515:65850707-3402-4c13-83bb-33bc4520a48fSimonr<p>Hi</p> <p>First off, what SDK are you using for development here?&nbsp;</p> <p>My first thought when reading this is that maybe the voltage rise time isn&#39;t within the specs when the battery is operating near depletion. According to the Recommended operating conditions, the Supply rise time from 0V to 1.7V should never be more than 60ms, and if that is, the power-on reset circuitry may not function properly.</p> <p><span>The threshold VPOF is set in the POFCON register. If the POF is enabled and the supply voltage falls below VPOF, the POFWARN event will be generated. The brown-out will always be enabled and always trigger if the voltage goes below 1.7V during run time.</span></p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>