[time-nuts] SITime oscillators

[Marek Peca]

> SITime just got some press for their temperature "insensitive" mems
> oscillators. I went to the web site and saw some interesting parts with
> pretty ambitious claims. Specifically better than Quartz.
> http://www.sitime.com/index.php
> http://www.sitime.com/products/datasheets/sit8208/SiT8208-datasheet.pdf
>
> They look too good to be true. However the phase noise plot stops at 1 KHz.
> There is another that stops at 100 Hz elsewhere on the site. Does anyone
> have real experience with the technology?

Not yet. I hope we will be able to buy few of them soon, if the price will 
be reasonable.

However, there was a good introductory presentation of SiTime founder 
Aaron Partridge two weeks ago at IFCS-EFTF conference, describing lots of 
their MEMS' internals. Basically, the fine frequency tuning and 
temperature independence is all done using frac-N PLL, implemented 
completely within ordinary non-MEMS CMOS chip. So, the MEMS osc output is 
not directly led out. The MEMS is there, as far as I got it, to maintain 
long-term stability.


Regards,
Marek