NRF52840 too high systemOFF current

[jonas.woerner]

Hi,

I am trying to get my systemOFF current below 1uA, but Im struggeling.

normally I use MBED, but to eliminate that variable, I just did a test without MBED, I took the nordic blinky example(SDK15.0) and added

sd_power_system_off();

to the

BLE_GAP_EVT_DISCONNECTED

so, when I connect and disconnect, the current drops from about 1mA to 36uA. This is exactly the same behaviour as I see on my application running with MBED.

So, its not MBEDs fault, so it must be mine.

what am I missing out?! I have searched through all of the posts about the systemOFF mode drawing too much current, but none of these problems were like mine.

Is it possible, that its because I am using an preview-DK? I have read all the errata about the first revision of the NRF, and didnt find something similiar to my problem.

thanks,

Jonas

[Simonr]

Hi Jonas

Due to the Easter holiday, we are understaffed and I cannot prioritize this request, as it still seems to fit the bill with USB interference. I can get back to you next week if you still want me to test this. Sorry for the inconvenience!

Best regards and happy Easter,

Simon

[jonas.woerner]

no problem, just test it whenever you have the time.

I just tested a few different things:

first I tested it with battery DUT supply instead of USB, but no change.

then I took one of the PCA10059 sticks and wired it up to the PPK, strangely it draws way more power than the DK does, why is that?

It draws about 100uA in systemOFF. does it have any peripheral that draws power that im not aware of?

so I still dont have a clue on whats going wrong...