nRF54L15DK system off current anomaly

RE: nRF54L15DK system off current anomaly

Tomas M — Thu, 27 Aug 2026 14:14:06 GMT

Hi Sean,

Sorry for the long wait with this issue... I did some digging and I don't think this issue has to do with NCS 3.3 vs 3.4. The hex files you sent on 8/12 are identical, so it seems like the version makes no difference for this specific application. Here is what I tried and the results I got. Let me know if you've discovered anything new on your end.

I built the following code using west build -b nrf54l15dk/nrf54l15/cpuapp

#include <stdio.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/poweroff.h>
#include <zephyr/drivers/timer/system_timer.h>

int main(void) {
    //Turn off GRTC and LF clock:
	sys_clock_disable();

    //Turn off RAM sections for CRACKEN and ICACHE:
	NRF_MEMCONF->POWER[1].RET &= ~0xE;

    //Enter System OFF:
	sys_poweroff();

	return 0;
}

I observed no issues when programming with west flash
I DID see issues with using nrfutil device program --firmware [path], but these resolved themselves with a reset.

I ALWAYS saw issues with the hex files you sent me, no matter which way I flashed, and which could not be resolved with a reset.

Let me know if you experience anything different.

Best,
Tomas

RE: nRF54L15DK system off current anomaly

Tomas M — Thu, 20 Aug 2026 15:20:15 GMT

Hi Sean,

Thank you for your patience with this topic. We are aware of several issues related to NCS 3.4, but I haven't found a good way to reliably replicate this issue on my end. In the meantime, I suggest developing on an earlier NCS version in which you don't experience these issues. I'll keep you updated as I get more information.

All the best,
Tomas

RE: nRF54L15DK system off current anomaly

sean — Thu, 20 Aug 2026 00:55:26 GMT

Hi，

Is there a patch available for this problem?

RE: nRF54L15DK system off current anomaly

Tomas M — Tue, 11 Aug 2026 12:51:57 GMT

Ah ok, I was able to reproduce that issue in 3.4. I will investigate it and bring it up with the NCS team.

RE: nRF54L15DK system off current anomaly

sean — Tue, 11 Aug 2026 10:10:27 GMT

Hi,

The following code will not work in ncs 3.4.0 when compiled and tested.ncs 3.3.0 is fine.

The sdk we need：ncs3.4.0

board：west build -b nrf54l15dk/nrf54l15/cpuapp

devzone.nordicsemi.com/.../l3_5F00_e1_5F00_sol.zip

# The following is the result of 3.3.0

devzone.nordicsemi.com/.../4745.zephyr.hex

# The following is the result of 3.4.0

devzone.nordicsemi.com/.../4745.zephyr.hex

RE: nRF54L15DK system off current anomaly

Tomas M — Tue, 11 Aug 2026 08:14:41 GMT

Here is the source code for that hex, as taken from this repo folder.

#include <stdio.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/poweroff.h>
#include <zephyr/drivers/timer/system_timer.h>

int main(void)
{
    //Turn off GRTC and LF clock:
	sys_clock_disable();

    //Turn off RAM sections for CRACKEN and ICACHE:
	NRF_MEMCONF->POWER[1].RET &= ~0xE;

    //Enter System OFF:
	sys_poweroff();

	return 0;
}

Let me know what results you get.

All the best,
Tomas

RE: nRF54L15DK system off current anomaly

sean — Tue, 11 Aug 2026 02:25:59 GMT

Hi，

I use following hex file, and the power consumption is normal, and the problem disappears, but I can't find the source code corresponding to this hex.

https://github.com/NordicDeveloperAcademy/bt-lowpow/blob/main/l3/l3_e1/hex_files/nrf54l15_xxaa_application.hex

RE: nRF54L15DK system off current anomaly

tzf — Mon, 10 Aug 2026 01:39:51 GMT

If the device is disconnected from power for a period of time, the chip power consumption will increase when it enters low-power mode again after power-on, exceeding 200uA in power consumption tests. If the reset pin is pulled low, the program will return to normal after resetting and entering low-power mode again.

RE: nRF54L15DK system off current anomaly

Tomas M — Fri, 07 Aug 2026 08:42:44 GMT

Hi Sean,

Higher current consumption is expected behavior after flashing a device. This can be caused by the MCU remaining in debug mode even after it's done flashing, so we recommend to always do a power cycle after programming.

Your System OFF current draw seems a little bit high even after the RESET, though. It should be somewhere around 0.7uA as per the datasheet. Would you be able to download and flash this minimal firmware and show the results? Here is the behavior I see on my end with this firmware:

Current is higher than normal after flashing, but this is fixed by power-cycling the device. Please provide a screenshot measuring the current after resetting, and we can see if there's something else going on.

Best regards,
Tomas