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Measurements >> Phase Noise and Jitter Measurements >> Influence of number of cycles on Jcc simulation
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Message started by tjaf on Oct 9^th, 2006, 2:42am

Title: Influence of number of cycles on Jcc simulation
Post by tjaf on Oct 9^th, 2006, 2:42am

In the paper "Predicting PhaseNoise + Jitter of PLL's" Jcc is defined as:

J_cc = sqrt[var(T_i+1 - T_i)]

When evaluating the jitter after a pss + pnoise simulation, I have to input an integration interval and the number of cycles 'k'. How does the latter relate to the definition of J_cc. Is it the amount of periods over which the variance is calculated?

Thanks,
Nick

Title: Re: Influence of number of cycles on Jcc simulatio
Post by aren on Nov 2^nd, 2006, 9:48am

Here is just my thinking.

I think the integration range gives you the edge jitter( jittered clock edge compares with ideal clock edge). And cycle number will give you how to calculate the N-cycle jitter from the edge jitter.
For the oscillator system, n-cycle jitter is calculated as sqrt(N)*edge_jitter. But for the driven system, the N-cycle jitter is not dependent on the cycle numbers, which is always sqrt(2)*edge_jitter.