My current consumption vs online power profiler estimation

RE: My current consumption vs online power profiler estimation

Einar Thorsrud — Mon, 11 Oct 2021 10:23:16 GMT

Hello,

I reproduced this myself using PPK2. It turns out that if you power the DUT using USB that causes noise that results in measurement errors. I recommend you remove the USB cable from the DK and power using a lab power supply instead. That will give you more accurate (and lower in this case) measurement results.

RE: My current consumption vs online power profiler estimation

kb2423 — Fri, 08 Oct 2021 19:32:15 GMT

I was using SDK 15.0.0 and downloaded same SDK again to be sure I didnt change anything. I did exact same changes with you.

Mesurement result was 75 uA.

Then I wanted to try latest SDK so I downloaded SDK 17.1.0 and made same changes. New measurement result was 68 uA.

I tried using SDK 15.0.0 and SDK 17.1.0 3 times and I got same results. So I will be waiting to hear from you. By the way my dev kit version is 2.1.0 . Thank you.

RE: My current consumption vs online power profiler estimation

Einar Thorsrud — Fri, 08 Oct 2021 10:56:40 GMT

I see. That looks OK to me. I will replicate your setup and test on my end on Monday.

RE: My current consumption vs online power profiler estimation

kb2423 — Thu, 07 Oct 2021 10:28:55 GMT

Thank you so much for your effort. Actually I tried to use external supply to get better solution so I tried to short SB12 which was so small. When I tried to do it I accidentally remove D1 diode and I couldn't put it back, now I cant program that dev kit. I have only one remaining kit so I didn't want to take risk that's why I am using USB as power supply. "Unless powered by USB, short solder bridge SB11 (if using coin cell battery) or SB12 (if using external power supply) to bypass the protection diode which would otherwise give a voltage drop." This was from infocenter, I think there is no need to modify dev kit except cutting SB9.

(This picture is from old versions, newer versions have diodes near SB12-SB11)

My connections are like that.

Power profiler software settings are same with this picture.

RE: My current consumption vs online power profiler estimation

Einar Thorsrud — Thu, 07 Oct 2021 08:21:44 GMT

I see, that is odd. I tested with the ble_app_blinky with a few minor modifications to get the same configuration as you:

devzone.nordicsemi.com/.../1817.main.c.diff

devzone.nordicsemi.com/.../sdk_5F00_config.h.diff

I did not have a PPK2 right now so I tested with the original PPK, and got numbers around 40 uA.

Perhaps what you are seeing is due to the measurement setup. Can you explain your measuring setup with the PPK2, both how you have connected it to the DK and how you have configured the PPK2 in the Power Profiler software?

RE: My current consumption vs online power profiler estimation

kb2423 — Tue, 05 Oct 2021 21:55:47 GMT

I commented out app_button library and everything about leds and buttons, it only changed 2 uA. I tested by connecting the board with nRF Connect and it doesnt react also current consumption doesnt increase when I press button so I am sure it disabled. These are the steps:

without modification        --> 1 mA
disabling NRF_LOG         --> 540 uA
adv interval 40 ms to 250 ms    --> 130 uA
enabling dcdc converter       --> 80 uA
disabling leds and button   --> 78 uA

Actually I did these steps many times because in some attempts I saw 70 uA, when this happens it lasts for minutes and when I upload any code even same code with same settings it becomes 78-80 uA again. I couldnt understand what is happenning.

RE: My current consumption vs online power profiler estimation

Einar Thorsrud — Tue, 05 Oct 2021 12:33:41 GMT

I see, that should be OK, then.

Can you remove the BSP and app_button code? The LED's should not contribute much as they are only sinked through the nRF, but the button code with GPIO interrupts will contribute a bit to the current consumption. So you should get better numbers by commenting out all calls to app_button_* and bsp_*.

RE: My current consumption vs online power profiler estimation

kb2423 — Mon, 04 Oct 2021 12:55:03 GMT

Sorry, I forgot to say that. I enabled DCDC converter, before enabling DCDC converter current consumption was around 100 uA, thanks to enabling DCDC converter it decreased to 75 uA.

RE: My current consumption vs online power profiler estimation

Einar Thorsrud — Mon, 04 Oct 2021 12:41:29 GMT

Hi,

I notice that you write that you disabled logging but you do not say anything about the DCDC. The example projects do not enable the DCDC by default so if you intend to use that you should enable it. If not, you need to disable DCDC in the Online power profiler, and you will get a number that is close to what you measure using the PPK2.