Dear All,

I am designing a PLL now.
I can run the VCO phase noise simulation, and got an acceptable result.
I want to see the overall phase noise performance of PLL.
So, I run the same simulation for PLL.
But the simulation always fails.
Cadence says the memory is insufficient, when pss is finished and pnoise is just started.
Sometime, the simulation can not converge when pss is running.

Is the direct PLL Pnoise simulation feasible?

Please help me~~~~~~~  

Chris,

  Performing PNOISE analysis requires a Periodic Steady-State
operating point. There are some points to consider:
1) Fractional-N PLL do not have periodic steady-state operating
   points so PSS/PNOISE can not be used
2) Finding the Periodic Steady-State of an Integer-N PLL is
   possible if the divide ratio is low
   --> I have simulated with divide rations of up to ~50
3) You will probably need to use the 64 bit executable
    --> I have found that this usually resolves the out of memory
          problem  
4) You should probably not save the transient data for the tstab
   and use the save selected to manage the amount of data
   stored
5) You probably need to use a longer stabilization time than the
   typically recommended, the PLL should basically be locked
6) I have used both the Shooting Newton and Harmonic Balance
   solvers to simulate the periodic steady-state
7) If you use the Shooting Newton solver, use it with APS-RF

  One other option to consider, is using the Noise-Aware PLL flow.
It will allow you to analyze noise to the block level quickly. While
the flow uses behavioral models, the behavioral model creation
has been automated.

                                                        Best Regards,

                                                           Sheldon

Dear All,

Thanks for your kindly reply.
I will try these solutions just mentioned.
Thank you very much!!

Chris