Low Jitter 20MHz oscillator

I have a cool Windows program that converts a phase noise profile to RMS jitter. Someone in SED supplied it (maybe you? I can't remember). The author isn't identified; it's PhaseNoiseCalc v 1.01 copyright ibrt 2003.

Dear Sir:-

I must object in the strongest terms to the above use of "begs the question".

Quite. Point taken. It prompts the question.

Jeroen Belleman

Or begs (for) the question, which is a common use.

n>>

The concept is pretty straight forward; take the single sided spectral noise power and convert it total rms jitter. Where?s it used, think about it for a second; What is one of the primary concerns when you apply a clk to any high performance digitizer?

What?s on the back end of any modern day acquisition system?

That's not an answer! You'll have to come up with something a little more explicit!

Jeroen Belleman

If the carrier-to-noise ratio is dominated by phase noise, the RMS phase jitter in radians is equal to 1/sqrt(CNR). You can derive that from the formula for sin(a+b), with a=omega*t and b a random variable.

For additive noise, it's 1/sqrt(2*CNR), because half of that noise power goes into AM (I) rather than PM (Q).

Cheers

Phil Hobbs

RMS jitter has to be specified over some observation interval. The frequency-domain phase noise spectrum gets mapped into the jitter-vs-time curve.

A cheap XO may have a picosecond of RMS jitter measured over single periods, and