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Long term jitter from SpectreRF's Phase noise?

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Hi,
 
It is true that we can get Jitter from Phase noise simulated from the Spectre by integrating over a noise band of interest. It evident that from the tool that we can get Jcc(cycle to Cycle Jitter) and Jee(Edge to Edge) and Jc.

But I want to know wether we can get "long term jitter" from the SpectreRF's Phase noise simulation.  kindly tell me wether we have any other ways to measure the long term jitter from the spectre.

I beleive the eyediagram technique with transient analysis will not include random noise and other noises.

Also in the Direct plot menu after Pnoise analysis. we have the term "K"( no of cycles). Can you pls tell me what is it.

Can we set k=3000 or (like that number ) to het the longterm jitter?

kindly reply.

Thanks & regards
SavithRu


Originally posted in cdnusers.org by savithru
Parents

  • Dear Andrew,

    Thank you very much for your kind reply. Thanks for clarifying me.

    ""you need to make sure you simulate the noise low enough in frequency to include noise over the total number of cycles you want to capture the long term jitter"' .... here noise, in low enough in frequency, meanse what? I have taken it as 10KHz (up to 100M) . Is that value is fine enough to my clock synthesizer driving CPU.


    While simulation, there is no option for giving the time for simulation or simulation of no. of cycles. I beleive the tool will do simulations only for few cycles, And later it only extrapolates for other k=higher values. If this is the case, I doubt that wether this Jitter for k= say 3000 is not realistc.


    Also can you please tell how I can measure the PFD+CP phase noise from Spectre. I want to compare the phase noise of CP+PFd+Divider+LPF with that of VCO.

    Kindly guide me.

    Thanks & Regards
    SavithRu




    Originally posted in cdnusers.org by savithru
Reply

  • Dear Andrew,

    Thank you very much for your kind reply. Thanks for clarifying me.

    ""you need to make sure you simulate the noise low enough in frequency to include noise over the total number of cycles you want to capture the long term jitter"' .... here noise, in low enough in frequency, meanse what? I have taken it as 10KHz (up to 100M) . Is that value is fine enough to my clock synthesizer driving CPU.


    While simulation, there is no option for giving the time for simulation or simulation of no. of cycles. I beleive the tool will do simulations only for few cycles, And later it only extrapolates for other k=higher values. If this is the case, I doubt that wether this Jitter for k= say 3000 is not realistc.


    Also can you please tell how I can measure the PFD+CP phase noise from Spectre. I want to compare the phase noise of CP+PFd+Divider+LPF with that of VCO.

    Kindly guide me.

    Thanks & Regards
    SavithRu




    Originally posted in cdnusers.org by savithru
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