Any Idea to do Simulation Crystal Oscillator in LT Spice ?

Thread Starter

mishra87

Joined Jan 17, 2016
741
Hello friend,

I just wanted to do simulation for crystal oscillator in LT Spice.
Can anybody give me any idea to start circuit for simulation ?

Thanks in Advance !!!
 

Papabravo

Joined Feb 24, 2006
13,728
Hello friend,

I just wanted to do simulation for crystal oscillator in LT Spice.
Can anybody give me any idea to start circuit for simulation ?

Thanks in Advance !!!
In the LTspice User's group at groups.io (the successor to the Yahoo group) there is an extensive set of threads on this subject. In the files section there are a number of examples. If you were a member of the Yahoo groups you should have been extended an invitation to the groups.io incarnation. They mostly center on using an equivalent circuit of L's 'n C's 'n R's to model the parameters of a particular crystal. Will this suffice for your purposes?
 

Thread Starter

mishra87

Joined Jan 17, 2016
741

Thread Starter

mishra87

Joined Jan 17, 2016
741
spreadsheet for electrical equivalent models of crystals was lost when my computer crashed leaving a void in public domain.
that was many years ago, great question. I found one page of several hundred that survived the attack. unverified remnants from xls . These were offpage subcircuits. artifacts survived computer attack which is common to public domain contributors.

View attachment 210849
Thanks,
Let me give it a try with opamp !

Regards,
 

sparky 1

Joined Nov 3, 2018
184
I messed up again these equivalents came from another source later not the old spreadsheet. I think it's on an old hard drive.
I should have backed up that spread sheet I really liked it. I also recall uploaded LTspice examples on the archive,
I needed those in 2016 made note regarding building from scratch.
I made note to myself it had this link to simulation values for electrical equivalents of crystals :
http://www.k8iqy.com/miscellaneous/XtalParms/xtal_parameters.htm
crystal equivalents can be modified as needed because buying wholesale crystals rarely have data sheets.
While K8igy mostly built crystal filters his use of AD9850 and op amp builds are interesting.
 
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sparky 1

Joined Nov 3, 2018
184
The crystal oscillator is unlike the other op amps circuits.
Some of the wave forms expected can be strange at first. Yet these forms are converted for very accurate timing.
In AN12-2 the logical progression from xtal to VCXO voltage controlled crystal oscillators. It begins with the famous LT1011 voltage comparator the simulator alone would not address these significant points about Xtal Osc. However LTspice can help to explore how op amps can accomplish incredible things shown in this application note will be important to a serious engineer. The explanation of the 85 kHz crystal osc using LT1011 figure 2 and 3 has a purpose that serves as framework even if you learned timers from a textbook learning, it differs from really nice precision like this progression into better and better methods instead of take your choice it adds merit about how and why an approach is chosen.
I do appreciate the threads and the simulation efforts here.
Application Note from Linear Technologies AN12-2 written by Jim Williams 1985
https://www.analog.com/media/en/technical-documentation/application-notes/an12fa.pdf

https://bgaudioclub.org/uploads/docs/Crystal_Oscillator_Circuits_Krieger_Matthys.pdf
 
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Papabravo

Joined Feb 24, 2006
13,728
It is because the standard distribution does not include everything that AB has collected. Look at the screenshots to see what components are contained in his libraries.
That would be the opamp and the crystal. You are also missing the 5V supply for the Microchip opamp.
 

Bordodynov

Joined May 20, 2015
2,604
Read message #8!
Add my library of models. How to do it is written on my web page and you will have many additional models. You will find additional items in ZZZ folder.

part.png
 
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