https://devzone.nordicsemi.com/f/nordic-q-a/3522/why-does-startup-of-nrf51822-take-massively-longer-with-lower-vddHi, I am evaluating the nRF51822 for an ultra low power energy harvesting application. I measured the time from power-on (VDD applied) to code exectution (GPIO toggle) using the PCA10005 Rev2.2.0 board from the nRF51822 development kit (Chip markingsen-USTelligent Community 13Fri, 20 Mar 2015 18:32:02 GMThttps://devzone.nordicsemi.com/thread/12754?ContentTypeID=1Fri, 20 Mar 2015 18:32:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:77a5001d-f1b1-4f8f-86dc-325886622c62Lukas_Simma<p>Hello,</p> <p>we develop for a battery driven environment sensor which should live many years from the battery. Today we got a new develboard (nrF6824) with nrf51822 which is Revision 3.</p> <p>Measured startups time is now constant We also see that the startup speed is faster then that we see on nrF51822 Revision 1 chip on 3 Volt.</p> <p>Many Thanks, Lukas</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/12753?ContentTypeID=1Wed, 27 Aug 2014 12:40:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:08d19a23-207e-473a-a16a-6995d9b56807Kenneth<p>Hi, to answer your questions:</p> <p>•why is the startup time loger with lower VDD?</p> <p>The short answer is that it is this way by design.</p> <p>•Can I do anything to reduce the startup time or the current consumption during startup?</p> <p>As you indicate you can reduce the startup time by increasing the supply voltage, that said the next hardware revision of the nRF51822 will address this challenge, so you should have short and constant startup time even for low voltages on the next revision. Please contact a regional sales manager on when that is available.</p><div style="clear:both;"></div>