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From: keithl@vice.UUCP
Newsgroups: sci.electronics
Subject: Re: Phase Jitter of a free-running oscillator
Message-ID: <1444@vice.TEK.COM>
Date: Mon, 16-Feb-87 23:45:30 EST
Article-I.D.: vice.1444
Posted: Mon Feb 16 23:45:30 1987
Date-Received: Wed, 18-Feb-87 03:35:36 EST
References: <5246@reed.UUCP> <919@unc.unc.UUCP>
Organization: Tektronix Inc., Beaverton, Or.
Lines: 19
Summary: analog oscillators DO jitter

In article <5246@reed.UUCP> mdr@reed.UUCP (Mike Rutenberg) writes:
>What is the "phase jitter of a free-running oscillator" and what does it
>depend on?  Does anyone have any revealing references?

Phase jitter in an analog oscillator can be caused by environmental 
variations such as supply ripple, temperature fluctuations, or
mechanical vibration, or simple thermal noise in the oscillator
or resonant device.  

Here at Tek, we have folk designing spectrum analyzers and various
sampling instruments who have sleepless nights about phase jitter,
and who attack the problem with surface acoustic wave oscillators
and other such esoterica.  They assure me that sub-picosecond movement
of edges on 100 MHz clocks are quite measurable and upset some of our
customers.

-- 
Keith Lofstrom
MS 59-316, Tektronix, PO 500, Beaverton OR 97077  (503)-627-4052