PLL jitter ang phase noise

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sadfish

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jitter pll

what's the different and relation ship between the jitter and phase noise?
IN pll design, what is the main source of jitter or phase noise. the noise of device(MOSFET , R), the fluntuation of the power&gnd ?
Another problem is how to simulate the jitter of PLL in hspice?
How can I measure the jitter in the output of hspice simulation result? when I simulate a PLL in hspice, I want to know the long time jitter and maxim cycle to cycle jitter, what should I do?
How can I analysis the spectrum of the jitter in hspice?
 

eye diagram simulation

sadfish said:
what's the different and relation ship between the jitter and phase noise?
they're two effects of the same phenomenon. Suppose to have a periodic waveform. Due to several noise sources the period won't be exactly the same at each cycle. For this reason if you analize the waveform in the frequency domain you won't see lines, but lorenz-like curves. You call this phenomenon phase-noise.
On the other hand if you analize the waveform in the time domain you will see a waveform with a period of a certain mean value T0 and a variance of deltaT^2. The variance is what you call jitter.
An approximated relationship between jitter and phase noise is:
S(deltaf)=(f0/deltaf^2)*[(deltaT/T0)^2]
where S is the phase noise, f0=1/T0 and deltaf if the difference between f0 and the frequency where you calculate phase noise. Actually the relationship is far more complicated but this is a good approximation in a large deltaf range.
sadfish said:
IN pll design, what is the main source of jitter or phase noise. the noise of device(MOSFET , R), the fluntuation of the power&gnd ?
That's a difficult to answer question. Suppose you have a PLL which is sinthesyzing a frequency f0. As i stated before you have phase noise surrounding your signals at frequencies f0+deltaf. For low values of deltaf the noise comes from the reference signal. For mean values of deltaf the noise is due to the loop filter. For high values of deltaf (usually important for adjacent channel interference) noise is due to the VCO.
Now each of these building blocks has its own noise sources which are related to the architecture and also to the layout realization of the block.
sorry i have no answer for this

hope this helps
 

analog devices phase noise jitter caliculator


How can I measure the jitter in the output of hspice simulation result?
when I simulate a PLL in hspice, I want to know the long time jitter and
maxim cycle to cycle jitter, what should I do?


I am not PLL designer, but as I know you may use some waveview tool
to open the output file of PLL. You may search Mentor Graphics or
sandwork site for more information. They may generate eye diagram of
period signal. But you know, it's waste much time and space to get the
long time jitter in simulation.
Hope it's useful for you
 

eye diagram hspice simulation

Possibility, the Hspice simulation can't include noise model. So, the eye diagram by close loop transient simulation is also not correct. I seem @DS can do it. I don't know.....
Anybody have ideal?
 

relationship between jitter and phase noise

How are you fight with vander?
 

pll spice simulation

i have a solution for ur problem.what u can do is to simulate ur pll in spectre.then note down the time when the pll locks,we need this value.now in analog environment of cadence open the results browser and right click on the node whose jitter needs to be measured to open the calculator then calculate the frequency and timeperiod of the waveform.then select th net again and click eyediagram in the calculator,u need to fill in the data.just enter the start time to be the time when ur pll locked and the end time to be the end of the transient simulation time,then enter the time period of the waveform.now plot the eye diagram.u will get the plot from which u can calculate the jitter.

regards
amarnath
 

waveview analyzer eye diagram how to plot

I can introduce you a good book "
PLL Performance, Simulation and Design", by Dean Banerjee. .
 

ads jitter noise problem

hello myicejaden,but please look at what the topic says.we have enough books on pll,but none of them tech u how to simulate and find out the jitter in a simulator like spectre.

regards
amarnath
 

how to measure pll jitter in hpice

2 amarnath:

The method you've described (eye diagram) does not need any Cadence Spectre's specific features - you can do eye diagram with any general SPICE (including HSPICE).

The problem with your method is that transient simulation does not include device noise, so your simulation will be too optimistic (or better say useless..)

Some possible solutions how to simulate jitter or phase noise in PLL using SpectreRF periodic analyses(both direct and inderect methods) are desicribed at www.designers-guide.org. Besides, envelope analyses in ADS might be a soultion.
 

jitter time simulator phase noise

they are the same go to T.H.Lee see how
 

pll jitter simulation

Use ADS can easily draw the eye diagram and There is jitter histogram in ADS design guide. I think this may measure the jitter; however, I don't know how to setup the measurement. Do anyone know that?
 

waveview analyzer eye diagram

integrate psd of phase noise you get jitter
 

how to simulatie phase noise in hspice

eric1341 said:
Possibility, the Hspice simulation can't include noise model. So, the eye diagram by close loop transient simulation is also not correct. I seem @DS can do it.


Would you like to explain in detail?
Regards.
 

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