Measuring frequency with LTspice

[carbonzit]

Is there any way to measure the frequency of a waveform generated by LTspice?

I know there's a fast Fourier transform function and display, but I'd really just like to know the (approximate) frequency of a particular waveform.

 

[ericgibbs]

Is there any way to measure the frequency of a waveform generated by LTspice?

I know there's a fast Fourier transform function and display, but I'd really just like to know the (approximate) frequency of a particular waveform.

hi cz,
Run the sim and create a plot.
1. hold down Ctrl key, right click on the waveform plot label [ at the top of the plot]

2. A small window will open, use the 'Attached Cursor' drop down box, select 1st & 2nd.

3. Two dashed 'axis' lines will appear on the plot, name '1' and '2'

4. place your cursor on '1' and hold down the left mouse key and move the '1' dashed line to a position on the plot waveform. Then do the same with '2' dashed line, place that one cycle away on the waveform.

5. There is a small window, bottom right of your screen.

6. it shows the Freq and other info on the '1' and '2' dashed line positions.

7. note also it shows the amplitude at the selected points.

BTW: I have that TwinTosc .asc if you want to play with it.

 

[ikelectro]

Hi eric!!!!
I now that i'm digging up a old thread.... is it possible to get the LM358 and LM393 in the LTSpice....?????/

 

[ericgibbs]

Hi eric!!!!
I now that i'm digging up a old thread.... is it possible to get the LM358 and LM393 in the LTSpice....?????/

hi ike,

I would recommend you join the free Yahoo LTS user group **broken link removed**

They have the two IC's in the LIB/FILES folder.

If you have a problem let me know.

E.

 

[ikelectro]

hi ike,

I would recommend you join the free Yahoo LTS user group **broken link removed**

They have the two IC's in the LIB/FILES folder.

If you have a problem let me know.

E.

Hi thanks eric for that link... but how should i use it.... i can't figure it out how add the files to LTspice.....

 

[ericgibbs]

Hi thanks eric for that link... but how should i use it.... i can't figure it out how add the files to LTspice.....

hi,
If the file you download is 'zipped' , unzip it.

You may see the following types of unzipped files:

Use Windows Explorer to move as required. [ my LTS is in C:\Program Files\LTC\LTspiceIV] , you may have chosen a different folder.


If you have: filename.lib move it to the C:\Program Files\LTC\LTspiceIV\lib

If you have: filename.mod or the filename.sub move it to the C:\Program Files\LTC\LTspiceIV\lib\sub

If you have: filename.asy move it to the C:\Program Files\LTC\LTspiceIV\lib\sym

Also most zipfiles have an testname.asc , this is the file you RUN with LTSpice

You should have the include directive already in the testname.asc file,, if you create a new design and you wish to use the filename.sub or .mod you need to type in the .include as in the original testname.asc

Let me know if you have a problem.

E

 

[MikeMl]

Hi thanks eric for that link... but how should i use it.... i can't figure it out how add the files to LTspice.....

The proceedure on how to augment the LTSpice library has been discussed hundreds of times on the Yahoo group and on these forums. Use the "Search" feature on either Yahoo or this forum. No point in rehashing it here...

 

[ikelectro]

Hi eric,

I have a .mod file for LM358 and I have moved it to C:\Program Files\LTC\LTspiceIV\lib\sub (as you have said

and my LT also in the same directory) ... but cant able to see or use the lm358 in my LTSpice!!! i think I have now only

problem with the .mod files!!!

 

[eTech]

Hi

You need to create a symbol file or use an existing symbol file, and associate the .mod file with it. The symbol file has a . asy file type.
If you want to use an existing symbol, try using the opamp2.asy

If you already placed the .mod file below the sub/ folder somewhere:
Add the opamp2.asy to the schematic,
then rht-clk the component name and change it to the exact name after the .subckt statement in the mod file.

eT