Products > Test Equipment

LCR Impedance Viewer for Picoscope+Keysight+R&S Bode Plot Data (open source)

<< < (24/30) > >>

Hans Polak:
In the image at the left Rref is a symbolic 2200, but in the simulation plot at the right I used the correct value of 100R as can be seen in the topline above the plot.

Hans Polak:
Hi Wim,

Here are the first results, resp the LTSpice plot, the Excel plot uncalibrated and the third one calibrated for the used probe,
and finally the recorded .CSV  File disguised as txt file.

Hans

_Wim_:

--- Quote from: Hans Polak on May 16, 2021, 10:21:43 am ---Hi Wim,

Step one.
I did the math my way with all the figures from the Tektronix article, and got the exact same figures as they did.

Hans

--- End quote ---

That is no surprise as the load is almost purely capacitive or inductive. What do you get when running the same CSV data with from above (with the positive gain) using the Tektronix formula's? I would guess you also get a negative ESR like I did and not the plot you posted.

You will not get my complete plot as I limit the gain to max zero dB, but at least you should verify if your claim from above is correct that there is a fault in my ESR calculation.

_Wim_:

--- Quote from: Hans Polak on May 16, 2021, 11:22:44 am ---Wim,
This is the test circuit I propose for testing the calibration with 1)probe alone and 2) probe +75pf
Can you agree with this ?

Hans

--- End quote ---

That looks ok to me

_Wim_:

--- Quote from: Hans Polak on May 16, 2021, 12:41:56 pm ---Hi Wim,

Here are the first results, resp the LTSpice plot, the Excel plot uncalibrated and the third one calibrated for the used probe,
and finally the recorded .CSV  File disguised as txt file.

Hans

--- End quote ---

I am not sure how I need to interpret these result. Is the just probe the result without the 75pF, the the calibrated the result with the 75pF cap & then calibrated? Can you post a plot where you see in one graph:

- DUT measured with no 75pf cap at scope input
- DUT measured with 75pf cap at scope input
- DUT measured with 75pf cap at scope input & with calibration correction implemented

1 & 3 should be identical in an ideal calibration situation, 2 should be different enough to see the calibration "working"

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod