hi zeros,
I have modified your original circuit, try it out.
E

 

hi zeros,
I have modified your original circuit, try it out.
E
View attachment 312356

@ericgibbs

Thank you for your attempt. I tried the new model you modified, and its result is still the same as before. This really confuses me. My focus has shifted from how to solve it to how to reproduce this error waveform. What factors in LTspice can cause different results in the same simulation file?

 

hi z,
It is a puzzle.
These are my settings in Toolsnmenu.
E

 

hi z,
It is a puzzle.
These are my settings in Toolsnmenu.
E

@ericgibbs
I changed the settings to match yours, but the result remained the same. However, I found that by changing the VCC value in the 74LVC1G126 properties from 5V to 4.8V, the output waveform was normal.

 

Hi z,
Are you saying the problem is now solved?

E

 

Hi z,
Are you saying the problem is now solved?

E

@ericgibbs Yes. What is the value of VCC in your 74LVC1G126 properties?

 

hi zoros,
This is my setting for the 1G126
E

 

hi zoros,
This is my setting for the 1G126
E

ok. Thanks!

 

Hello,
74HCT573 test circuit (include model, symbol(s)).
You will need the 74HCT_v.lib library file (not included).

 

Hello,
74HCT573 test circuit (include model, symbol(s)).
You will need the 74HCT_v.lib library file (not included).

View attachment 312428

@eetech00
Thank you for your assistance. The model you encapsulated is really good, it works normally and is concise and clear. I have two questions:
1.How was the .lib 74HCT573.txt file written? This method of describing sub-circuits through text fascinates me. Is it in SPICE language?

2.You passed a value of 4.5V to VCC, but when I changed it to 5V, it still seems to work normally. However, earlier in this post, the value of VCC in the model shared by ericgibbs seemed to have a significant impact on the 74LVC1G126. By reducing the value of VCC, I was able to get normal waveforms from the circuit. As a beginner, I am still confused: why do I get significantly different results from ericgibbs using the same model file?

 

@eetech00
Thank you for your assistance. The model you encapsulated is really good, it works normally and is concise and clear. I have two questions:
1.How was the .lib 74HCT573.txt file written? This method of describing sub-circuits through text fascinates me. Is it in SPICE language?

Yes. It is a version of SPICE language.
I used a method of structuring, writing and calling subcircuits to define the model. It makes the code efficient, easy to adjust, and troubleshoot. I've been writing models a long time, and also know the subject spice code model libraries very well.

2.You passed a value of 4.5V to VCC, but when I changed it to 5V, it still seems to work normally. However, earlier in this post, the value of VCC in the model shared by ericgibbs seemed to have a significant impact on the 74LVC1G126. By reducing the value of VCC, I was able to get normal waveforms from the circuit. As a beginner, I am still confused: why do I get significantly different results from ericgibbs using the same model file?

You'll have to ask @ericgibbs that question.

 

Yes. It is a version of SPICE language.
I used a method of structuring, writing and calling subcircuits to define the model. It makes the code efficient, easy to adjust, and troubleshoot. I've been writing models a long time, and also know the subject spice code model libraries very well.



You'll have to ask @ericgibbs that question.

@eetech00

Thank you very much for your reply, it has been very helpful to me.

 

I would like to thank everyone for their replies and help. I believe that the topic: Building a HCT573 model in LTspice, has been well resolved. Thank you again for your assistance!

 

2.You passed a value of 4.5V to VCC, but when I changed it to 5V, it still seems to work normally. However, earlier in this post, the value of VCC in the model shared by ericgibbs seemed to have a significant impact on the 74LVC1G126. By reducing the value of VCC, I was able to get normal waveforms from the circuit. As a beginner, I am still confused: why do I get significantly different results from ericgibbs using the same model file?

Hi zeros.
I used only the files you posted in post #4 and worked OK, to show the Q output I had to include a pull-up resistor to +5V.
I have tested your files on another PC and I get the same OK result?

E

 

Hi zeros.
I used only the files you posted in post #4 and worked OK, to show the Q output I had to include a pull-up resistor to +5V.
I have tested your files on another PC and I get the same OK result?

E

@ericgibbs Thank you for your attempt again. I have decided to let go of this issue, and my friend has told me about Schrödinger's Cat.

 

Hi z,
Thanks, I know exactly what you mean.
E