RE: PPK reports different average current if trigger is running.

wlgrd — Fri, 10 Mar 2017 10:22:59 GMT

No worries, I rarely read them myself ;) So, are we marking this as solved?

RE: PPK reports different average current if trigger is running.

CurtisHx — Thu, 09 Mar 2017 14:16:02 GMT

Pretty sure what I'm seeing is from that warning. That's what I get for not RTFM... The average window was fully populated and the cursors fully encompassed the average window. The two average numbers match.

RE: PPK reports different average current if trigger is running.

wlgrd — Thu, 09 Mar 2017 09:30:16 GMT

This might be because the triggering is causing a lot of glitches. As stated in the user guide:

What it forgets to mention is that a lot of triggering can also cause glitches in the average plot, since the trigger window has the higher priority due to it's high accuracy. I also see that your max value is much lower on the second image, and will clearly be visible on the graphs.

Without looking at the actual plots you have, it is hard to say what exactly is causing this (since I haven't seen it before), but the avg: number is reporting the average for the full average window. Make sure the whole window is populated. You may also try to compare e.g sleep values by using the cursors, and see if the average number is different there with and without the trigger enabled.

I would assume the data without the trigger active is the correct number, but please edit you post with the plot screenshots so that we can be sure. Also, you should calibrate your resistor values, they doesn't seem correct to me. To do this, measure the output voltage of the External DUT, insert a resistor (one at a time) to draw 30µA, 1mA and 10mA. So for e.g Mid, the new value will be

1mA/measurement28. I.e, if you measure 0.9mA, the new value will be 1/0.928=31.11.

RE: PPK reports different average current if trigger is running.

wlgrd — Thu, 09 Mar 2017 09:04:49 GMT

Can you post screenshots of the average window in these two cases?