PPK ampere mode high peaks

[maya_sa]

Hello, 
I ran the nrfconnect (ver 3.7.1) in Power Profiler (ver 3.1.3) in BLE advertising.

When I run the source mode on 3000V I get normal peaks  (20mA), however when I run the Ampere mode with the same voltage I see peaks of 45-50 mA.

On a different PC (same PS and cable , same nrf version and power profiler version) both Ampere mode and Source mode show the same values (as they should).

Thank you for your help.

[maya_sa]

Hi , Windows 10 pro (on both pc), 64 bit 

And yes I have followed the setup in the same way both times

[JONATHAN LL]

Then it could be noise from the USB port, do you consistently get higher spikes on all USB port on the on PC with higher spikes?

Regards,
Jonathan

[JONATHAN LL]

Need to ask you for one more thing, could you click on the save/export and save as PPK and csv and share both. 


Regards,
Jonathan

[maya_sa]

ppkexports.zip the ppk and csv are in this zip , didnt let me upload separately 

[JONATHAN LL]

Thanks, 

Seems to be a strange artifact, could you provide some more info on the two computers. 

Are both intel computers?

And can you test with a USB 2.0 hub ?

Regards,
Jonathan

[maya_sa]

I have tested with a usb 2.0 hub and no change in the values
both pc's are intel computers 

[JONATHAN LL]

Hi, thanks for the information so far, i dont have a solution for you, but i do have some more options for you to try and a questions. This is a very unique issue you have come across and it is very interesting for us to debug. 


Was the USB hub you used powered externally also, or just from USB on computer?

Could you use a USB charger and connect a cable to the "USB power Only" connector. Want to check if the computer you are using has some supply irregularities from the USB ports. 


Regards,
Jonathan

[maya_sa]

The USB hub was powered from the USB on the pc.

I have used an external USB charger and connected to the "USB power only" connector.

the results are as expected (the good ones) 

[JONATHAN LL]

Looks like the issue is with the USB supply from your computer then, do you have a lot of other devices plugged in to the computer at the same time?
It might be noise from ground or from a different device connected to the computer, cant really say what exactly is the issue. 

But by using a different power source and suppling through USB power only you are able to get the correct measurements on the "bad" computer. So you have at least a work around at the moment. 

Will do some more pondering on this case and update wit any news, or if you have any more questions feel free to ask. 

Regards,
Jonathan