Hi everyone Does anyone know what is the unloaded quality factor of the quartz crystal ? since I searched over many datasheets and I can't find it

Not sure which resonance frequency and size you are looking at, but you can assume a few thousand. BTW, are you referring to the quartz material itself, or a packaged component?

The resonance frequency is 10MHz. Yes, I'm referring to the package component

Try to find a datasheet that gives series and parallel resonance, and ESR and C0. From omega_p and omega_s you can find keff. With keff and C0 you can calculate Cm. From resonance frequency and Cm you can find Lm. With Lm and ESR (or Cm and ESR) you can calculate Q.

Thank you for your help Actually most of datasheets state only the fundamental frequency so, I'll try to find a one that contains both

Assume k_eff^2 of 1%, and you can approximate the rest (should be good enough for practical use).

Based on the datasheet, I have Co of 7pf and ESR of 40 ohms so I have Cm of 56.74fF, Lm of 4.46mH and Q of 7K

@Tarek Nasser: Does this mean you're designing a crystal oscillator for the SkyWater process?

@Tarek Nasser sounds like reasonable values.

@Tim Edwards yes I do

@Tarek Nasser: Wonderful! Please keep me informed on what tapeout your circuit is on, once you get it on a tapeout. It is a piece of IP that is very high on my wish list.

I'm doing a Pierce oscillator. Actually we are working on a Bluetooth PLL With Eng. @Amro Tork that hopefully will be finished by the next MPW. here is the link of the git repo: https://github.com/mabrains/PLL_design

@Tim Edwards We are currently working on this. @mkk Already knows about this work. @Tim Edwards Let me know if you have any questions.

@Tarek Nasser, @Amro Tork: Thank you both!