LTspice model for CD4017?

Thread Starter

wayneh

Joined Sep 9, 2010
17,496
I'm unsure of the inputs to the 4017 symbol. I've gone to the Yahoo group to get the CD4000_v.lib file, the CD4000 symbols folder and the instructions, and I have successfully added the symbol and model to my project.

But the I don't get what those 3 inputs are. I need Reset, Clock and Enable. It appears they are listed top-down in that order on the symbol, but I'm not sure. Do you agree?

Screen Shot 2014-10-27 at 10.28.25 AM.png
 

Papabravo

Joined Feb 24, 2006
21,159
Why do you think the inputs on the symbol are something else?
R=RESET seems obvious.
You can configure the "Clock" to have either an active high enable or an active low enable. Whichever input is used for the enable, the other input is the clock. That is the meaning of the half circle that looks like an AND gate.
 

Thread Starter

wayneh

Joined Sep 9, 2010
17,496
Now I'm having a different issue with the 4017 model:
Screen Shot 2014-10-27 at 12.20.28 PM.png
This model is supposed to allow using the actual circuit voltage as entered into the attributes for the symbol. Whether I edit the default Vdd=5 or leave it alone, it resets itself to 5V and throws this error at me. What am I missing?
 

Thread Starter

wayneh

Joined Sep 9, 2010
17,496
The symbol provided for the 4017 (posted in #1) does not have supply pins.

BUT, the trick is to add a "Net Name" of Vdd to the positive rail of the power supply. Works like a charm now! That's probably what you meant?

Thanks.
 
Last edited:

Papabravo

Joined Feb 24, 2006
21,159
Just good old ignorance. My chip has an "E" pin and the symbol doesn't. Your explanation makes sense as to why that is.
Sometimes the internal logic is conveyed by the symbol and sometimes it is obfuscated. Glad you were able to resolve the situation.
 
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