Originally Posted by JohnW
I'm quite weary about NDK parts (although I use there Temp compensated VCXO parts).
A while back we measured the phase noise of new MEMs type parts and remeasured about a year later only to find a significant increase in phase noise with age - so it appears that MEMs oscillators wear out over time...
I've never read any details about this - so stay WELL away from MEM's parts.
What worries me about NDK parts is that its not clear if the part is a real Crystal based clock or MEM's - I've seen the MEM's parts described as Crystal oscillator modules, when the are clearly not - (MEM's is not a Quarts Crystal).
While the NDK SA parts might be really good parts (never measured or used them) - I'd recommend Crystek 90.3M / 98.3M parts and Divide down by 4 to 22M / 24M, this results in a 12dB reduction in phase noise (and buffers the Oscillator circuit from external loading effects).
The Crystek 90.3M / 98.3M XO's will also be a higher Q overtone circuits - again very good for phase noise.
The NDK parts are clearly crystal oscillators. I'm not sure why you would think otherwise. It's MEMS not MEM's, also. SiTime claims no aging mechanism and a quick search could produce nothing indicating that will happen. Forgive me for believing them for now over your uncontrolled test of sample size N=1.
Last edited by chris719; Today at 07:06 PM.