nRF52833 power consumption after upgrade to SDK 1.7.1

[ecsfang]

Hi,

After upgrade from nRF Connect SDK 1.4.1 to SDK 1.7.1 we have seen an increase of the current consumption with about 100uA.

Before with SDK 1.4.1 the idle current was about ~60uA, but now we see peaks with about 300uA at about 300Hz (see included picture).

I have tested both with our main application as well with a simple test application (that just initialize all pins then goes into idle).

I have also tested on two different product samples, and the scenario is the same, but the frequency differs from 2.7ms to 3.4ms (290-370Hz).

At this stage we are not using BLE, and the test application just initialize all pins, powers off all external sensors etc and just goes into idle. We just rebuild our applications with the API changes that was needed between 1.4.1 and 1.7.1 so our code is the "same" in both scenarios.

Any ideas why this differs between the two SDK's? Could it be something that we have missed to configure when upgrading from 1.4.1 to 1.7.1 that causes these 300Hz power peaks?

Best regards,
Thomas

[Simonr]

Hi Thomas

Would it be able to get the project configuration or a small sample project so we can reproduce this on our end, no luck in finding someone seeing the same behavior thus far I'm afraid.

Best regards,

Simon

[ecsfang]

Hi Simon,

Thanks for your reply, yes I could share the configuration file, but first I like to tell what I found last evening.

As mentioned, when we compile and run using SDK 1.4.1 we end up at about 60uA in idle, but building same app for SDK 1.7.1 results in ~140uA.

So, I went through all pins and peripherals to see if I could find what caused this, and I ended up in the configuration  

    CONFIG_BOOTLOADER_MCUBOOT=y

If I compile and run with this setting (also included in the 1.4.1 build) I get ~140uA (shown in yellow in the picture), but if I remove this setting I end up with the original ~60uA (shown in red).

So, with this finding I have the following result:

  CONFIG_BOOTLOADER_MCUBOOT=y in SDK 1.4.1 results in ~60uA

  CONFIG_BOOTLOADER_MCUBOOT=y in SDK 1.7.1 results in ~140uA

  CONFIG_BOOTLOADER_MCUBOOT=n in SDK 1.7.1 results in ~60uA

I found a similar issue (https://devzone.nordicsemi.com/f/nordic-q-a/59709/config_bootloader_mcuboot-costing-hundreds-of-ua), but if I try the solution given there I see no difference, I only see the difference if I turn the configuration off  (CONFIG_BOOTLOADER_MCUBOOT=n).

Any ideas about this?

Best regards,

Thomas

(Sorry about the picture - I don't know how to include with higher resolution - it worked in the original post ... :( )