Question about crystal oscillator circuit.

[didibabawu]

In the circuit is it a crystal oscillator? Has anyone seen this circuit? Please Give me more imformation about it. Thank you very much.

 

[A.Anand Srinivasan]

ya it is a oscillator... the crystal gives 180 degree phase shift and the inverter gives 180 degree phase shift based on its sizing...

 

[nguyennam]

The inverter is a CMOS IC.

 

[didibabawu]

ya it is a oscillator... the crystal gives 180 degree phase shift and the inverter gives 180 degree phase shift based on its sizing...

Then how can i know the circuit is work well.

 

[holddreams]

ya it is a oscillator... the crystal gives 180 degree phase shift and the inverter gives 180 degree phase shift based on its sizing...

Then how can i know the circuit is work well.

Given the crystal equivalent model,you can run the simulation of AC,transient,etc.

 

[SWINI]

ya it is oscillator but how to identify exactly whether it is crystal oscillator or not from its view???rather from its action...

 

[A.Anand Srinivasan]

every crystal has its own characteristic frequency and if the inverter can operate at that frequency.... i mean cross the threshold of the inverter in the on time period at that frequency then the oscillator will work....

 

[gte582w]

Also, recall in Razavi's book, he derived that there
is an equivalent nagative resistance between the drain and gate when there are caps between gate/source and drain/source, inverter is just a stack of these two. So it's still in a form of, let's say, colpitts oscillator.

 

[lijianheng]

yes, it is a positive fed loop.