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

Do you also see the same measurement errors when lowering the sampling rate? Do you also see the same difference in measurements if using a DK as the DUT, or just your custom board? I will try to reproduce this and report it internally, but in the meantime you can try rolling back to the previous version.

In case this is phantom spikes due to the level shifters on the PPK2 switching a lot. You can also open the advances settings on the Power Profiler app with ctrl+shift+alt+A to try and tweak the voltage spikes parameter to mitigate this. The simpler fix if that's the case will be to just use the lower sampling rate.

Best regards,

Simon

[mcu8484]

Thank you for the response.  It's a custom board and I did try 10ksps and got only marginally better results.  This might be a dumb question but how do I rollback to previous version?  The user manual doesn't seem have such info.