nRF54L15 + MX25R64 Idle Power Consumption

[Patrick]

Hi there,

I'm working with a custom board based on the Raytac AN54L15Q module and encountering higher-than-expected power consumption when trying to profile using the system_off example from the nRF Connect SDK.

Current Status

• Running the system_off sample with modifications to power down the external flash (MX25R64).
• Power drops from ~1.86 mA to ~16 μA after powering down the flash.
• I'm unable to get below ~16 μA, which seems too high for full system_off state.

Board Configuration

• RGB LED connected to GPIOs P1.09, P1.10, P1.11, configured as GPIO_ACTIVE_LOW | GPIO_PULL_UP.
• Button connected to GPIO P0.03, configured as GPIO_ACTIVE_LOW | GPIO_PULL_UP.
• MX25R64 flash connected via Port 2 (same as the nrf54l15dk reference)
• SHT41 sensor on P1.04 and P1.05.
• LFXO is mounted and using internal load capacitors.
• No UARTs enabled in the device tree.
• Same result whether building against nrf54l15dk_nrf54l15_cpuapp or using my own board definitions.
• I do not have a devkit, so I’m unable to cross-check behavior on official hardware.

I have not explicitly power managed the SHT41, but its idle current is far lower than what I am seeing. In another project, I have explicitly disabled all peripherals except SPI00 and still cannot break the ~16uA barrier so I am at a loss.

Any guidance on what to double-check for getting down to expected power levels in system_off greatly appreciated. 

[Patrick]

I have attached my board files for reference. Since my post I have removed the pull-up from the LED GPIO config. I have also modified pinctrl sleep definitions from 'low-power-enable' to 'bias-disable'. 

When power profiling, I do have my jlink attached to the board, but not running. Unplugging the debugger causes a slight increase in power consumption.

rsense_duo.zip