HI Everyone!

I am attempting to recreate these two graphs seen here
These both come from my source material that may be found here:

Source App Note

Thus far I have followed the app note exactly (to ensure I have something to check against), however I am having difficulty getting my graphs to mirror those of the APP note. Namely my Gain plot seen here:
This Gain plot seems to be negated from what I would expect.

The Impedance Plot seen here:

Is right in line with what I would expect however I am unable to figure out how to make the Log ohms Y axis and Log frequency based X axis.

My file may be found here:HELPED_Input_Filter_Test_V1.sm (181,95 KiB) scaricato 1271 volta(e).

Thank you all in advance,
Carlo

1. The APP notes were done Mathcad 8 or later 2001i, 11
from lazy grid colors [horrible green].
2. First graph as before.
3. Not visible math expressions are for recycle bin.
4. NEVER carry units in maths as they are unit less.
5. Smath is not Mathcad clone.
6. Maybe your construction is not correct wrt APP Notes ???
I didn't check that ...

2DPlots ZedGraph log-log.sm (100,84 KiB) scaricato 1334 volta(e).

HELPED_Input_Filter_Test_V1 ... first graph doctored.sm (187,74 KiB) scaricato 1318 volta(e).

The Maxima plugin provides an interface to Gnuplot. This can be used to come pretty close to Mathcad plots.
You can set the minor grid to gray and remove the dashed line style, to have a more SMath-like appearance.
Note that the Draw2D() command is written in the input placeholder of an image region.


HELPED_Input_Filter_Test_V1_Kr.sm (353,57 KiB) scaricato 1276 volta(e).

Wrote

HI Everyone!

1. You refer to an application from source and the
first thing you do is freak the variables from source ... Why ?
2. Mathcad 8 was index ... like you try to imitate,
that's retarded because Smath is already in argument style s(j)
The main change from Mathcad 8 => 2001i was the change from
s[i [index style] => argument style s(j)
3. I couldn't make Zgraph work [spooky plugin]
... from there, some Collab might help ?

HELPED_Input_Filter_Test_V1 ... first graph doctored NEW.sm (125,46 KiB) scaricato 1305 volta(e).

Wrote

HI Everyone!
...

This Gain plot seems to be negated from what I would expect.
...

Hi Carlo. That's because you take log10 in the y-axis before plotting. I put images in the other post. Check the green lines in Mathcad plots. First plot isn't in log scale in the y-axis.

Best regards.
Alvaro

Wrote

This Gain plot seems to be negated from what I would expect.

You mean IMPEDANCE plot as per MCD 8
Impedance plot has a part negative from its quadratic.



HELPED_Input_Filter_Test_V1 ... first graph doctored NEW...next.sm (127,12 KiB) scaricato 1263 volta(e).

... I will leave it there ... which one of the 3 plots.
loglog plot is freaked to me [personal].

HELPED_Input_Filter_Test_V1 ... first graph doctored NEW...next.sm (132,32 KiB) scaricato 1351 volta(e).

Well Guys after ALOT of struggling with Maxima (Which for whatever reason isnt working for me) I finally got ZEDgraph to work for me!

The Finished Document may be found here:SMPS_Input_Filter_Design_TI_APP_Note.sm (555,35 KiB) scaricato 1694 volta(e).
And I was finally able to recreate the graphs!







[albumimg]1606[/albumimg]


Again this is pretty much a direct recreation of the TI App note, but it served for a great learning experience!

I will be sure to PROPERLY post it under the samples area along with the app note

Thank you guys again!!! (Especially Jean/Razonar)

Wrote

... I will leave it there ... which one of the 3 plots.
loglog plot is freaked to me [personal].

HELPED_Input_Filter_Test_V1 ... first graph doctored NEW...next.sm (132,32 KiB) scaricato 1351 volta(e).

Well it turns out that I was taking a doulbe LOG of the graph! Silly Me!