I am getting an error due to the fact my schematic only has behavioral
model for inverter, not analog.

Searching web has been discouraging, cannot seem to find a CD4049
model or a 74HC04 model to do this with. Let alone get it imported into LTC.

Any help greatly appreciated.

Regards, Dana.

 

The CD4000 and 74HC models I have are all behavior models and will not likely work well either in your simulation.
Are you trying to simulate a linear phase-shift oscillator or a relaxation (with hysteresis) phase-shift oscillator?

 

That specific config of 3 inverters and 3 RC networks to gen the remaining
180 degrees needed to oscillate. Using CMOS inverters.

Searching the web I did find http://www.youspice.com/?s=cmos+inverter
but if possible I would like to get to a commercial standard logic cmos
inverter model, one that I can bench correlate to.

Regards, Dana.

 

Hi

74HCU04 unbuffered inverters
spice mode must be device level models to work.
See attached.

 

Here are the LTspice files I use to simulate the CD4000 and 74HC00 digital families.
Unzip the Digital file and replace the Digital file you have in the sym folder (after backing it up) with the unzipped one.
Also add the two .lib files to the LTspice lib folder.

Add the .include cd4000_V.lib or .include 74HC_V.lib file as need in the simulation schematic.

You also must add a power supply for the logic elements labeled Vcc for the 74HC and Vdd for the CD4000 in the schematic.

 

crutschow thanks for the effort you have spent on this.

Is this the procedure, in addition to your instructions, I need to use to
get the library to work ?

https://electronics.stackexchange.c...open-library-file-for-a-third-party-amplifier

Right now I cannot find either symbol/inverter when I go to place the component.
I verified the lib stuff is in lib folder, and Digital Folder has your unzipped replacement.

The two .libs are in C:\Program Files\LTC\LTspiceXVII\lib
The digital folder is in C:\Program Files\LTC\LTspiceXVII\lib\sym

I double checked the search path LTC uses to find stuff, in fact it was
empty, put the correct paths in. See attached.

If you would not mind post your .asc file you did sim with, I would be grateful.



Regards, Dana.

 

You can use the default 'A' devices if you right-click and give them some parameters, including a bit of hysteresis.

 

Here you have the results made in the best in the world simulator (mother nature).

R = 10kΩ; C = 1nF; IC = CD4069; Vdd = 5V



And the same as before but this time with a Schmitt trigger CD40106 ( Schmitt trigger input)

 

You need to close LTspice and reopen it to find any new files you've added.
Did you do that?

 

Yes, even looked to see if there was an index file to erase to get reinitialized
for the added components. Did not work.

So I used you file, it cannot find symbols or library, even though I have used
control panel to explicitly point to them. Gah.......

Regards, Dana.

 

See

 

@Jony130, can you post your file, and what is the sim you are using ?

@Bordodynov please post your file.

Regards, Dana.

 

Hello,

Is it possible to force the inverters to linear mode using a resistor from 1 to 10 M between in and output?
I have used it to create an amplifier for RF with it:



Bertus

 

@Jony130, can you post your file, and what is the sim you are using ?

I build this circuit on a breadboard and use my rigol scope to measure it.

 

cannot find symbols or library, even though I have used
control panel to explicitly point to them. Gah.....

Although LTS installs files where you want them, it also copies them to the User/Documents folder tree in Win10 and only looks for them there. Try copying them to ..... User/Documents/LTspiceXV11/lib (and ...... lib/sym for the symbols).

 

See

 

The use of non-buffered logic at the transistor level.
My Model Library:
https://forum.allaboutcircuits.com/...nents-models-of-ltspice-free-download.133690/

 

Elements 4000A is not buffered logic,
Elements of 4000B are buffered logic,
Elements 4000UB is not buffered logic, it has a permissible power of 15V.

 

Yes, even looked to see if there was an index file to erase to get reinitialized
for the added components. Did not work.

So I used you file, it cannot find symbols or library, even though I have used
control panel to explicitly point to them. Gah.......

Regards, Dana.

If you just want to run the sim for this schematic, then just make sure the 74HC_v.lib file and symbol .asy file is in the same folder as the schematic .asc file.
Try this zip file.
Unzip the file, browse to the .asc file, then open .asc with LTspice.

You can figure out how to manage the libraries later..

eT

 

I found the problem, I think with symbol and library
search paths.

A post on web discussed that LTC looks in its folder in "Documents" even though
its install puts all its models in both "Documents/LTCxxx" and "C:/Programs/LTCxxx.

And in control panel path has to be set to the "Documents" path.

Clearly a bug in LTC.

Thanks all for the help, I am up and running.

Regards, Dana