NFC system off current

[imcbuyer]

I am currently working on a project using the nRF52840-DK and the Power Profiler Kit II. I have created an application based on the "NFC System Off" sample. However, I am experiencing an issue with the current consumption.

The minimum current I can achieve is around 200 µA, which is significantly higher than expected for the system off mode. According to the nRF52840 specifications, the current consumption in the system off mode with RAM retention should be in the range of a few microamperes (typically around 0.4 µA).

Could you please provide guidance on how to reduce the current consumption to the expected levels? Any advice or troubleshooting steps would be greatly appreciated.

[Priyanka]

Hi,

There are quite a few ways to try reducing the current consumption. 

Please make sure that you are using the DCDC mode and also a crystal with minimum startup current. Please take a look at this ticket where I have described a few steps.

Make sure that you disable all unused peripherals. Please also make sure that your external components are not drawing any extra or idle current. 

Using the PPI peripheral and also trying to use proper connection parameters so that unwanted use of the radio is limited can also help.

Please also refer to this power optimization documentation for the nRF52 series

and also to the following:

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/test_and_optimize/optimizing/power.html 

Regards,

Priyanka

[imcbuyer]

Hi Priyanka,

Thank you for your prompt response and the detailed suggestions.

I wanted to let you know that I found the cause of the high current consumption. After adding the line "CONFIG_PM_DEVICE=y" in the prj.conf file, the current dropped to a few hundred nanoamperes.

I appreciate your support and the resources you provided. I will still review the documentation to further optimize my application.

Thank you once again for your assistance.

Best regards,