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Sleep current on #nrf52480


Fabien Lepoutre
 

Hi all,

I've ran some power consumption tests with Zephyr 1.12 #... a00646a5

Using the samples/boards/nrf52/pwr_mgr at lowest power mode, I find that the nrf52840 has a sleep current of ~550uA.

When I run simple power management code with Nordic SDK in sleep mode,  I get about ~30uA.

To run these tests, I used the PCA52840 PDK board and measured the current using the Nordic Power Profiler Kit and also a third party solution. I'm confident the current numbers are right.

Has anyone ran sleep power measurements on the nrf52840 and have different results? 
I would like to understand the discrepancy between Zephyr OS and nordic SDK to bring down my current power numbers to the SDK ones.

Thanks a lot!


Sebastian Boe
 

550uA usually means that the HFCLK is running.

The HFCLK will run when something (peripheral) needs it.

You need to find out what is using it, unfortunately neither the HW
or the SW is able to tell you this, so if I was you I would manually (using CMSIS)
start turning everything off until the current died down.

Timers, etc.

NRF_TIMER0->TASKS_STOP = 1;

etc.

after finding the peripheral that is requesting HFCLK I would find out which SW
module turned it on and if it makes sense for it be on (is this a bug or not).
________________________________________
From: devel@... <devel@...> on behalf of Fabien Lepoutre <fabien@...>
Sent: Friday, 29 June 2018 1:28:45 AM
To: zephyr-devel@...
Subject: [Zephyr-devel] Sleep current on #nRF52480

Hi all,

I've ran some power consumption tests with Zephyr 1.12 #... a00646a5

Using the samples/boards/nrf52/pwr_mgr at lowest power mode, I find that the nrf52840 has a sleep current of ~550uA.

When I run simple power management code with Nordic SDK in sleep mode, I get about ~30uA.

To run these tests, I used the PCA52840 PDK board and measured the current using the Nordic Power Profiler Kit and also a third party solution. I'm confident the current numbers are right.

Has anyone ran sleep power measurements on the nrf52840 and have different results?
I would like to understand the discrepancy between Zephyr OS and nordic SDK to bring down my current power numbers to the SDK ones.

Thanks a lot!


ismael fillonneau
 

 Hi 
You could also try following patch which is currently under review:

Regards,
Ismael