[time-nuts] femtosecond jitter anyone?

[Richard (Rick) Karlquist]

Bruce Griffiths wrote:

> Some ECL devices have jitter specs in the 100 to 200fsec range.
> see:
> http://www.onsemi.com
>

This is misleading.  While it is true that they have this
low jitter at multi-Gb/s rates, the jitter is much greater
than this at lower clock rates.  At 10 MHz, ECL devices
can't do better than several ps random jitter.  This is
because of the broadband phase noise floor which is around
-150 dBc/Hz.

Rick Karlquist N6RK