pca10040 current measurement if boot by powerup 9uA

[jasonbu]

Just do NRF_POWER->SYSTEMOFF = 1; in main()

and found if it's boot by powerup the current is 10.4uA~10.5uA

and if a re-flash the hex, the current is 1.4~1.5uA

so confusing

[Stefan Birnir Sverrisson]

Hi

I tried this and got the same result on my nRF52-DK. However, I do not see this behavior if I disconnect the USB supply power, install battery, and then power reset. Then I see around 0.2uA both before and after the power reset. USB supply power will also add ~1uA to the current consumption so measuring low currents with battery is the way to go. Expected sleep currents are listed here