Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Ian Daintith — Wed, 17 Dec 2025 18:21:57 GMT

We verified low power on our depopulated board.

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Ian Daintith — Thu, 11 Dec 2025 10:26:52 GMT

Hi Kazi

We waited 6 days for this reply and you kindly went on to explain about DCDC.

You missed the point where I said we are NOT using DCDC.

So we have simple code running at a DK that take 2uAmps, run it on our depopulated custom PCB and it take 740uAmps. So I look at the differences.

1. DK uses DCDC. Our PCB does not.

2. Our PCB has VDDH and VDD tied together the DK does not.

I have shared the DTS and DTSI with you at the start of this ticket 2 weeks ago.

I cannot share the schematic on a public forum but happy to send to you privately if you can advise on how to do that.

So the question still stands - what could cause the consumption to be in the order of 740uAmps for such simple code on a depopulated custom PCB?

Regards

Ian

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Kazi Afroza Sultana — Wed, 10 Dec 2025 15:47:22 GMT

Hello Ian,

DC DC enabled generally should not be the cause of higher current consumption. Correct DC DC can ensure lower current consumption.

It would be helpful if you can share your schematic so I can see how VDD is routed on the custom board and if the DCDC components (LC filter) is correctly populated according to our schematic.

I also need to check the pinctrl.dtsi file from board file.

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Ian Daintith — Fri, 05 Dec 2025 13:33:16 GMT

Thank you Kazi. Yes I have since managed to measure the current on the nrf52833 DK correctly at ~2uAmp. ( see here. Definitive guide on measuring current using PPK2 + nRF 52833 DK )

So we have a situation where this simple code below takes

2uAmp on nRF 52833 DK

740Amps on custom depopulated PCB.

I have shared the DTS and DTSI with you.

One key difference I can see with the DK is that we are not using DCDC.

We do not understand what could still be running on the nRF 52833.

Thank you

Ian

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Kazi Afroza Sultana — Fri, 05 Dec 2025 12:25:05 GMT

Hello,

For measuring current using source meter, the VOUT pin of PPK will be connected to VDD pin of nRF current measurement header and GND will be connected to minus pin of external supply.

I can see you have connected to VOUT to the external supply.

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Ian Daintith — Mon, 01 Dec 2025 16:23:02 GMT

Hello Kazi

We repeated the tests on 3 x nRF 52833 DK using the Nordic procedure defined here https://docs.nordicsemi.com/bundle/ug_nrf52833_dk/page/UG/dk/hw_measure_current.html. Using the PPK2 as source meter.

DK1 - 8uAmps

DK2 - 8uAmps

DK3 - ~600uAmps

The boards appear identical to us in configuration. All 3 flashed from Visual Code NCS Extension SDK v3.1.0.

We cannot explain the difference on DK3. Do you have any ideas please?

DK1 showing 8.34uA

DK3 Showing ~ 600uAmps. - SAME CODE!

Board set up

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Ian Daintith — Fri, 28 Nov 2025 15:16:03 GMT

Hi Kazi, thank your reply. We will test this as you suggest on Monday 1 Dec and report the results.

RE: Cannot achieve low-power on nRF52833 custom PCB using simplest main() yields 740uAmps

Kazi Afroza Sultana — Fri, 28 Nov 2025 14:43:02 GMT

Hello,

Did you try the sample with the nRF52833 DK and check if you can get the current in range?

I can see that you disabled almost all unused peripheral in the overlay. However, to make it sure I would like to suggest you run only a minimal sample without for loop part. for example:

void main(void)
{
    // Minimal init only
    k_sleep(K_FOREVER);
    // or: sys_poweroff();
}

If the current consumption still not in specified range, then we can say there are other peripheral still enabled or some issue on the board.

Try this first and let me know the outcome.

Thanks.

Kazi