NRF52840 not going into systemOFF

[jonas.woerner]

Hi,

after having a little break from ot and working on another project, I am back working on getting the NRF into systemOFF. to get back into it I just made a very small program, I just used the nordic template_project and added

NRF_POWER->SYSTEMOFF = 1;

with the PPK connected I can see that power consumption indeed goes down, but I still se about 40uA of current.

by disconnecting the Debugger, I can see the current drop another 5-10uA, but thats still way to high.

measured using the PPK with external LiIon battery as power source.

[Jared]

Hi,

• Where in the code do you place the line?
• Which softdevice and SDK version are you using?
• Which version of the nRF52840 are you using? Are you using the DK or a custom board?
• Could you try flashing the DUT with the pwr proifling example from the SDK. What current do you measure?
• Do you have an ammeter available so that you can see if you measure the same current?

Regards

Jared 

[jonas.woerner]

I placed it right in main()

sdk14 with the 5.0.2-alpha (also tried with 6.0 in SDK15)

no, I dont have a meter with that precision.

but I found out, that it might be faulty measssurements imn doing.

how can I supply the DK with external dut power supply? because strangely, if I use external supply and DUT select is on DK, I read way more current than if I use DK power for measuring...

If I measure an external device, like the NRF usb stick, then I really get to sub 1uA. So how do I measure the DK properly?

[Jared]

Hi,

Please refer to Figure 2. Measuring current on custom hardware with an external power source and the nRF5 DK

Regards

Jared