https://devzone.nordicsemi.com/f/nordic-q-a/126817/npm1300-ldo-vout-off-stateHi there, I am considering using one of the npm1300 LDOs to supply 3.6V to the battery backup pin of a uBlox MAX-M10 module using a 100uF capacitor as energy storage for backup power over a few seconds (to allow system power cycle and minimising GNSSen-USTelligent Community 13Tue, 03 Feb 2026 11:13:41 GMThttps://devzone.nordicsemi.com/thread/560215?ContentTypeID=1Tue, 03 Feb 2026 11:13:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1872fe5d-444f-449b-9eb8-a97f263a2f21Richard_P<p>Thank you!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/560209?ContentTypeID=1Tue, 03 Feb 2026 10:35:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:474fa2ab-81eb-4c0c-b2a2-0235d093cbeaSzabolcs<p>Hi Rich,</p> <p>When the LDO/LS is off and the discharge resistor is disabled, the VOUT pin is in High-Z mode. However, there is an ESD protection diode from the VOUT to the VSYS pin, so if the VSYS voltage is lower, the VOUT voltage can backfeed into the VSYS pin.&nbsp;</p> <p>So yes, if you want to keep voltage on the VOUT pin while the VSYS is down, then a reverse-current protection circuit is recommended.</p><div style="clear:both;"></div>