Need 74HCT573 model in LTspice.

Thread Starter

zeros

Joined Nov 27, 2023
26
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? 1704886849083.png
 

Thread Starter

zeros

Joined Nov 27, 2023
26
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

Joined Jun 8, 2013
4,004
@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.
 

Thread Starter

zeros

Joined Nov 27, 2023
26
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.
 

Thread Starter

zeros

Joined Nov 27, 2023
26
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!
 

ericgibbs

Joined Jan 29, 2010
18,980
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
 

Thread Starter

zeros

Joined Nov 27, 2023
26
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.
 
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