Quote:As I mentioned before, a large signal negative resistance analysis will provide an accurate assessment of sustaining amplifier input impedance from which an excellent estimate of the actual oscillation frequency may be obtained.
If I'm not wrong you are refering to :
Quote:Re{ Zin } + Re {Xtal_unit} = 0 and Im{ Zin } + Im{ Xtal_unit} = 0.
Well I read a lot of things about negative resistance on the internet (publications mostly) most of them stops at the gm_opt to have the best start-up time. I must admit that as most of them stopped their analysis with this tool at this point, I thought that there was nothing more.
About quartz litterature, you must be refering to :
Quote: Texts by Ballato, Rhea, and Parzen come to mind. Tutorials by John Vig are also a very good introduction to the field.
I think I found John Vig tutorial online (is it a powerpoint?).
If I wanted to fully understand the negative resistance approach for crystal oscillator, which book should I buy to do so?
Thank you for your help and sorry about asking the same questions over and over again, I think that it's still not clear for me.
EDIT : Have you got the titles of the books you advised me to read? I tried finding them online and one of them cost like 700 USD I hope it's not that one.
EDIT 2 : I think I found them all, but they cost a lot of money as an intern I'm not sure I can afford it.
The only book I can buy is :
Design of Crystal and other harmonic Oscillators by Benjamin Parzen. Will this book tell me enough about negative resistance?
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EDIT 3 :
Okay, I redid the negative resistance simulation by removing the quartz, adding a current source and the C0 of the quartz I'm using (5pF).
Small signal analysis :
The AC signal allowed me go get Re(amp) = -147 Ohm. The ESR of the quartz is 21.58 Ohm, therefore I have gain.
I got the X(amp) by plotting the imaginary part of the voltage drop across the quartz unit, X(amp) = -287 (Ohm?)
The phase calculated is Arctan(-287/-147) = 62.9°. Cadence told me that the phase was -117°, 62.9° - 180° = -117° so it's okay.
Now in order to determine the Re(amp) at steady state I need to run a large signal analysis. And the problem is here, how do I do that?
Do I put the crystal back?
Because if I don't, I don't think that the PSS analysis will converge at all. So my question is how do I simulate large signal analysis?
Thank you very much for your help.