crystal simulation in LT Spice

ericgibbs

Joined Jan 29, 2010
18,226
Hi 777,
You need to set Vhigh=5 in the Inverter model, also the 'u' symbol is missing off the 5.366 d-15u.
Doing further tests on your circuit.
E
 

ericgibbs

Joined Jan 29, 2010
18,226
hi 777,
The circuit will not run with the basic inverter delays etc. so tried with 74HCT04 as a test.
The 5.66 e-15 is not recognized by LTS, so used a 5.66p
What is the purpose 0F capacitor across the 100k ?
Also, LTS reported an open Out pin, so added a 1meg.
There appears to be a design problem.
E
EG57_ 793.png
 

Attachments

Papabravo

Joined Feb 24, 2006
20,603
The following simulation demonstrates how to model a crystal and how to determine both the series and parallel resonant frequencies. You can then take these parameters and make them into a subcircuit.

1682436602070.png
Green trace is the circuit on the left., and the blue trace is the circuit on the right.
1682436737352.png
 

Attachments

Papabravo

Joined Feb 24, 2006
20,603
It may not be obvious from the above simulation, but the FREQ, Q, C and RS values define the values of the motional components, AND the motional components define the FREQ, Q, C and RS values.
 

Papabravo

Joined Feb 24, 2006
20,603
I don't think you can get rid of it completely. Is there a small amount of time where the startup transient would be acceptable? If not, then I fear your quest will be fruitless.
 
Top