https://devzone.nordicsemi.com/f/nordic-q-a/91161/protection-diodes-on-nrf52840-clamping-currentI&#39;m developing an application using the NRF52840. I&#39;m using the ADC, and there may be times where the signal to be measured is up to 1.8V, but the NRF52840 is not yet powered (i.e. VDD = 0). One option I am considering is to put a resistor in series withen-USTelligent Community 13Tue, 23 Aug 2022 11:40:45 GMThttps://devzone.nordicsemi.com/thread/382905?ContentTypeID=1Tue, 23 Aug 2022 11:40:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:df67ad04-cd06-440e-aacb-27bb3375d84eStian R&#248;ed Hafskjold<p>Nordic agrees :) Use an external switch</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/382536?ContentTypeID=1Sun, 21 Aug 2022 22:23:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:47ee06a7-7ef6-4ef5-968c-078f863710e5hmolesworth<p>There is no safe value low enough to allow the SAADC to acquire an accurate reading. The reason is interference with the reset functionality as before reset occurs current consumption can be extremely low such that the shottky clamp diode current is high enough (&gt; few 10s nA) to start the power up but interfere with reset, most notably on a brown-out or VDD dip where the brown-out condition reset never completes as the voltage is held too high at (say) 20nA supply. Alternatives require an external switch: FET normally off or Ideal Diode normally off or Flying Capacitor or ...The &quot;on&quot; signal doesn&#39;t need to be a port pin, it can be the output of an on-board regulator on the nRF52 or even VDD. 20nA at 3V is 150MOhm. Is this a problem for every powerup/VDD dip? No. Is it a problem with shipped product on site? Yes .. eventually. There is no specification for this condition as maximum ratings are being violated. Nordic&nbsp;might disagree (hopefully) :-)</p><div style="clear:both;"></div>