NRF5340 low-power measurement with PPK2

[Bas van den Berg]

Hi,

I aw various other posts ( nRF5340-DK Low Power Configuration Issues)

and the post on Optimizing power on nRF53 designs  but I never get results that low.

The Blog post doesn't really help, since it only states the Zephyr settings and not the

real software settings. Using the example from the post mentioned above gets the same

results (650 uA on 1800 mV)

Our setup:

PPK as power supply for NRF5430-DK (version 0.11.0)

SB40 is bridged

SW6 to DEFAULT (if no nRFOnly, more current seems to run)

SW9 to VDD

SW10 to ON

For software:

basic loop, while(1) { WFI(); }

and 100 Hz RTC1 based TICK.

HFCLKSRC = HFINT

Other peripherals idle.

When I measure is still get around 650 uA when setting PPK supply to 1800 mV. (around 1000 uA when 3000 mV).

So 2 questions:

- is the hardware setup ok?

- what can we do in the software?

[Simonr]

Hi

We can do a meeting if you'd like, but that would have to wait until Monday (I will be free from 10:30 to 11:30 and 14:00 to 15:30). Unfortunately it seems like you have two defect PPK2's though, if the behavior is like this on both PPKs, where all the maximum spikes are exactly the same (713.24µA on the one you sent to us). 

If you have a resistor available (3kOhm or larger) it would be helpful to see what you measure over a known load in Source Meter mode with 3V applied. 3V on a 3kOhm should show a 1mA current consumption. It would also help if you have a resistor large enough to get under 10µA available (so larger than 300kOhm). 

Finally, if we could get the serial numbers of the PPKs you have we can check the test logs of them as well.

Best regards,

Simon

[Jester]

At least one PPK is working correct.

3V/3301 ohm should read  908,815510451 uA
3V/328.850 ohm should read  9,122700319 uA

So that seems to be OK at least for the source meter part although i would not want to call it accurate.
But let's ignore the accuracy for now. We more or less have a decent measurement with values that can be explained.