High power consumption on nRF5340 custom board

RE: High power consumption on nRF5340 custom board

Michael Crevier — Thu, 09 Oct 2025 10:50:40 GMT

Hi Kenneth,

I did some tests, and when the power consumption is lower, the COEX pins are ~0.6V, data0 and data1 (MOSI and MISO in SPI mode) are 0V and 0.6V respectively. data2 and data3 are ~1.0V. IOVDD and CLK are 0V, BUCKEN 0.4V and SS 1.8V.

However, when the power consumption is high, I observed IOVDD at 0.7V. All other pins are ~0.7V except SS and BUCKEN, which are around the same level as before (1.8V and 0.3V).

I will perform some more tests on other devices to confirm the behavior.

I guess that the problem is the the IOVDD pin controlled by a switch linked to P0.31 don't go back to 0V... Is that a known issue? What can I do to solve that?

Thanks
Michael

RE: High power consumption on nRF5340 custom board

Kenneth — Wed, 17 Sep 2025 08:20:49 GMT

Hello,

Can it be that some of the pins are kept high when wifi is shutdown? Can you for instance go over the SPI interface (e.g. CSN pins) and others and check if may be possible you are setting any of those pins high when wifi is shutdown? This could cause current flowing through the gpio into the nRF7002.

Kenneth

RE: High power consumption on nRF5340 custom board

Michael Crevier — Tue, 16 Sep 2025 17:25:35 GMT

Kenneth

Any thoughts on this?

RE: High power consumption on nRF5340 custom board

Michael Crevier — Fri, 29 Aug 2025 00:17:46 GMT

Hi Kenneth,

I tested the Wi-Fi shutdown sample on my board using SDK v2.5.2 and v3.0.1.

SDK v2.5.2

SDK v3.0.1

In both cases, I noticed no spike after shutting down the Wi-Fi. The only difference between the two builds is the base board configuration (nRF7002Dk and nRF5340DK+nRF7002EK respectively). I added an overlay to adapt both boards to my device, so the final device tree should be identical.

Do you have any thoughts on what might be causing this behavior?

Thanks,
Michael

RE: High power consumption on nRF5340 custom board

Kenneth — Tue, 26 Aug 2025 11:52:46 GMT

Hi,

Maybe the Wi-Fi: Shutdown sample can be helpful for debugging.

Kenneth

RE: High power consumption on nRF5340 custom board

Michael Crevier — Fri, 22 Aug 2025 23:27:21 GMT

Here is a test with the hello world sample. I set every peripheral to disabled (uart too, so UART_CONSOLE=n).

Debug (before first Wi-Fi ON event)

Debug (after Wi-Fi OFF)

Debug (with no contact on UART pins)

Prod (before first Wi-Fi ON event)

Prod (after Wi-Fi OFF)

Prod (poweroff)

RE: High power consumption on nRF5340 custom board

Michael Crevier — Thu, 21 Aug 2025 22:14:18 GMT

Hi,

I went trough the documentation once again and realize that my child imag for the net core didn't had the custom overlay file, so I added that. The power went dows a bit, but not by much and I still have a quite high power consumption avter turning the Wi-Fi OFF a second time.

Before first Wi-Fi sending

After first Wi-Fi sending

Power OFF

As for the CONFIG_PM, I had this warning, so I figured out it was not supported on the nRF5340. However I have the CONFIG_PM_DEVICE and CONFIG_PM_DEVICE_RUNTIME enabled.

warning: PM (defined at soc/arm/microchip_mec\mec172x\Kconfig.defconfig.series:36,
soc/arm/silabs_exx32\efr32bg22\Kconfig.defconfig.series:18,
soc/arm/silabs_exx32\efr32bg27\Kconfig.defconfig.series:18,
soc/arm/silabs_exx32\efr32mg24\Kconfig.defconfig.series:19, subsys/pm/Kconfig:13) was assigned the
value 'y' but got the value 'n'. Check these unsatisfied dependencies: (SOC_SERIES_MEC172X ||
(SOC_SERIES_EFR32BG22 && SOC_FAMILY_EXX32) || (SOC_SERIES_EFR32BG27 && SOC_FAMILY_EXX32) ||
(SOC_SERIES_EFR32MG24 && SOC_FAMILY_EXX32) || (SYS_CLOCK_EXISTS && HAS_PM)) (=n). See
http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_PM and/or look up PM in the
menuconfig/guiconfig interface. The Application Development Primer, Setting Configuration Values,
and Kconfig - Tips and Best Practices sections of the manual might be helpful too.

Also, I'm on the SDK v2.5.2, does it have some know power consumption issues?

Thanks,

RE: High power consumption on nRF5340 custom board

Kenneth — Thu, 21 Aug 2025 18:43:22 GMT

Sounds good, I cant seem to find CONFIG_PM enabled anywhere, I would expect that is needed also.

Kenneth

RE: High power consumption on nRF5340 custom board

Michael Crevier — Thu, 21 Aug 2025 15:29:23 GMT

Hi Kenneth,

The measurement include the whole board, so nRF5340, nRf7002, mx25r64 FLASH and IMU.

I already took a look at that documentation, but I will make sure everything is well applied and do some more measurement to share the results with you.

Thanks,

Micahel

RE: High power consumption on nRF5340 custom board

Kenneth — Thu, 21 Aug 2025 11:50:58 GMT

I would start by investigating the system OFF current.

[quote user=""]

System Off (prod build)

[/quote]

This shouldn't really be possible. Is the supply rail you are measuring on here only going to the nRF5340, or does it also include the flash memory and IMU?

Possible check if you may be sourcing some current through pins also.

Edit: Also check out in general:
https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/test_and_optimize/optimizing/power.html

It might be a good idea to try to narrow down the functionality in the app a bit and see if any specific modules seems to cause the increased current consumption.

Kenneth