nRF54LM20A DK sleep current much higher than datasheet (measuring ~89 µA vs. 4 µA)

RE: nRF54LM20A DK sleep current much higher than datasheet (measuring ~89 µA vs. 4 µA)

strongman — Fri, 30 Jan 2026 07:33:16 GMT

The root cause of the higher-than-expected sleep current was that the DCDC regulator had not been explicitly enabled in the firmware.

After manually configuring and enabling the DCDC mode, the measured sleep current now matches the values described in the documentation.

Thank you for your support and feedback.

RE: nRF54LM20A DK sleep current much higher than datasheet (measuring ~89 µA vs. 4 µA)

strongman — Fri, 30 Jan 2026 01:54:12 GMT

I’m not using the nRF Connect SDK Bare Metal option.

I’m running my own minimal bare‑metal firmware built directly on top of nrfx 4.0.1, compiled with the Arm GCC toolchain. I’ve already verified that the compiled program runs correctly on the target; now I’m just trying to get the CPU into a low‑power System ON idle state using WFE without explicitly initializing any peripherals.

RE: nRF54LM20A DK sleep current much higher than datasheet (measuring ~89 µA vs. 4 µA)

Michal — Thu, 29 Jan 2026 22:48:27 GMT

[quote user=""]Firmware: bare‑metal, no peripherals explicitly initialized, just trying to put the CPU into a low‑power System ON idle state using WFE.[/quote]

Does that mean that you are running our nRF Connect SDK Bare Metal option https://www.nordicsemi.com/Products/Development-software/nRF-Connect-SDK/Bare-Metal-option-for-nRF54L-Series

Or just trying to run your own minimalistic bare-metal firmware (if so, how are you compiling it)?

Best regards,

Michal

RE: nRF54LM20A DK sleep current much higher than datasheet (measuring ~89 µA vs. 4 µA)

strongman — Thu, 29 Jan 2026 10:23:08 GMT

I have verified my measurement setup using the system_off sample from nRF Connect SDK, and the measured current matches the values in the documentation. This confirms that my measurement method and hardware setup are correct.

However, I still cannot find the reason why the power consumption of my bare‑metal firmware is significantly higher than expected. Could you please help me identify what might be causing the higher current draw in the bare‑metal implementation, and which checks or configurations I should focus on?