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Design >> Mixed-Signal Design >> Regarding Jitter.
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Message started by smarty on Jun 6^th, 2007, 7:04am

Title: Regarding Jitter.
Post by smarty on Jun 6^th, 2007, 7:04am

Hi all,
I have a basic question relating to Data dependant jitter. Its a combination of ISI, DCD and other effects.
I see that to remove the ISI effect and evaluate DCD, provide a 101010.. pattern. Is it the correct method by which the DCD can be calculated.

Also Can anybody suggest, how can the DCD measured in terms of time. What I know till now is DCD is the variation of duty cycle
from the normal value and can be measured in %(50% ideal) ( pls. correct me if my understanding is wrong). So if I need to know the DCD
in terms of time, how can that be done?.

Is there any paper, which gives me some good ideas regading the various jitter and its effects?.

One more in the same context. How can we evaluate various jitter from the Eye diagram?. Can anybody suggest any paper relating to this.

Thanks and Regards,
SBR

Title: Re: Regarding Jitter.
Post by mg777 on Jun 6^th, 2007, 8:28am

Jitter due to ISI and DCD are invariably mixed up - both can give rise to dual Dirac pdf's, and you worry about deconvolving these only if you're selling jitter analyzers. The 1010... technique usually works for DCD, while the more sophisticated analysis techniques operate in the spectral domain.

M.G.Rajan
www.eecalc.com

Title: Re: Regarding Jitter.
Post by smarty on Jun 6^th, 2007, 10:31am

Hi Rajan,
Thanks for your inputs.

Actually I planned to run spectre simulations to estimate the DCD.
So in order to eliminate the other other effect , I thought it would be best to give a 101010.. pattern
and estimate the DCD at the output.

Can DCD be estimated from the eye diagram?. Could you kindly clarify one query of mine.

when we plot the eye diagram for te data pattern, We see a bunch of transition forming eye.
What will be the jitter that would be corresponding to this bunch?. Is this the peak-to-peak jitter or any other
jitter?.

Thanks and Regards,
S.Baanurathan