Power Profiler Kit II issues after update

[mcu8484]

I just updated to Power Profiler 4.2.0 and PPK2 firmware 1.2.0 and now I see the big changes with the exact same DUT and setup compared to the Power Profiler 4.1.2:

* Current measurements at 100Ksps are now 5-10x higher.

* >3x difference between Source Meter and Ampere Meter modes compared to <30% difference before.

 

Has anyone else seen such changes?  I don't believe the new measurements are accurate.  Is it possible to downgrade?

I am using the default config values and here is the nRFConnect System Report:

# nRFConnect System Report - 2024-08-06T01-58-17.281Z

- System: Micro-Star International Co., Ltd. MS-7B45
- BIOS: American Megatrends Inc. A.90
- CPU: 1 x Intel Core i7-8700 3.2 GHz 12 cores (6 physical)
- Memory: 1.1 GB free of 46.9 GB total
- Filesystem: efivarfs (efivarfs) 256 kB 16.7% used

- OS: Ubuntu (22.04.4 LTS) linux x64

- Versions
- kernel: 6.5.0-45-generic
- git: 2.34.1
- node: 20.14.0
- python: 3.10.12
- python3: 3.10.12
- nrfutil-nrfutil-device: 2.3.5
- Connected devices:
- DA702E4DA3EA : /dev/ttyACM0, /dev/ttyACM1

- Current device:
- name: PPK2
- serialNumber: DA702E4DA3EA
- cores: Unknown
- website: https://www.nordicsemi.com/Software-and-tools/Development-Tools/Power-Profiler-Kit-2

[Simonr]

Hi

Thank you for letting me know. Not a dumb question at all, as it is a bit hidden. You can roll back the version by entering the dropdown menu for the app in the nRF Connect for Desktop launcher and select uninstall. After uninstalling you can "install other version" to choose an older one.

I tested this briefly on my end today with an nRF52840 DK running a BLE central with the Nordic UART service and saw very similar current draws on both v4.1.x and v4.2.0 of the Power Profiler app both in Ampere meter mode and Source meter mode. Can you upload a photo of how you've connected the PPK to your DUT, and what exactly is the DUT you're measuring current consumption on.

Best regards,

Simon

[mcu8484]

Thanks for the info.  I downgraded back to v4.1.2 and everything looks normal again.  Here is a photo of the setup in source meter mode.  Nothing unusual as far as I know.  Not sure how much it matters but there is DC-DC converter on the board that switches up to 2MHz.  I imagine that may cause quite a bit of high frequency current spikes confusing the new SW version?

[Simonr]

Hmm, that could be it. Your setup seems to be correct, so I don't know what else there could be. Are you fine with using the older version for now? I don't think a quick fix will be available any time soon unfortunately.

Best regards;
Simon

[mcu8484]

I am fine with old version for now.  I only upgraded because the release notes mentioned a fix for deteriorating performance for high sampling rates which looks like something that I have seen but not a critical issue at this point.