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 How to find the Phase Noise for the DIVIDER 

Last post Wed, Mar 28 2012 6:27 AM by RFQuery. 4 replies.
Started by RFQuery 25 Mar 2012 08:57 PM. Topic has 4 replies and 3623 views
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  • Sun, Mar 25 2012 8:57 PM

    • RFQuery
    • Top 75 Contributor
    • Joined on Wed, Jul 20 2011
    • Posts 89
    • Points 1,270
    How to find the Phase Noise for the DIVIDER Reply

    Dear all,

    I want to  simulate the phase noise of my divider which take input differential clock source (ideal).

    Can any body tell how can I do the phase noise simulation. ( please point to any suitable documents)

     I want to do following simulations with the divider

    1)  simulate without any phase noise  in the  clock

    2) simulate with certain amount phase noise  in the  clock

    3) Lastly, I want to make some trasnsistors of the divider NOISELESS and then do the phase noise simulation

    I could make the flicker noise of desired MOS transistors zero but How can I make thier thermal NOISe zero.

     

    • Post Points: 20
  • Wed, Mar 28 2012 4:40 AM

    • Frank Wiedmann
    • Top 75 Contributor
    • Joined on Thu, Jul 17 2008
    • Muenchen, Bavaria
    • Posts 81
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    Re: How to find the Phase Noise for the DIVIDER Reply
    • Post Points: 20
  • Wed, Mar 28 2012 4:52 AM

    Re: How to find the Phase Noise for the DIVIDER Reply

     Actually you can turn off the noise contribution of specified devices (or only enable noise contribution of specified devices if that's more convenient) at the bottom of the Simulation->Options->Analog form (Main tab) in the "NOISE OPTIONS" section. This corresponds to these spectre options (from "spectre -h options") :

     Noise parameters
    51      noiseon_inst=[...]
                              The list of instances to be considered as noisy during all noise analysis, such as
                              noise, sp noise, pnoise and tran noise.
    52      noiseoff_inst=[...]
                              The list of instances to be considered as not noisy during all noise analyses, such as
                              noise, sp noise, pnoise and tran noise.

    You'll need to be using a recent enough version of spectre and ADE to be able to set these (although if ADE doesn't provide the option in the version you're using, you could use the "Additional Arguments" field on the Simulation->Options->Analog form (on Miscellaneous tab, or at the bottom in IC5141) to type in noiseoff_inst=[...] etc.

    Regards,

    Andrew.

    • Post Points: 35
  • Wed, Mar 28 2012 6:26 AM

    • RFQuery
    • Top 75 Contributor
    • Joined on Wed, Jul 20 2011
    • Posts 89
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    Re: How to find the Phase Noise for the DIVIDER Reply

     Dear Andrew,

    Thanks a lot for your reply.

    I am using MMSIM10 but I am not sure whether it is the latest one.

    However I couldn't find the NOISE OPTION in the ADE-SIMULATION-ANALOG-OPTIONS form.

    I wrote in OTHER OPTIONS section as suggested by you. I have attached the snapshot how I have entered.

    Could you please have a look at it and tell me whether it is correct.

    One more doubt:- Whether this take only INSTANCES ? 

                            I have a MOS in the schematic with name NM11. If I write, noiseoff_inst=[I561 NM11], will it be OK ?

    Kind Regards

    • Post Points: 5
  • Wed, Mar 28 2012 6:27 AM

    • RFQuery
    • Top 75 Contributor
    • Joined on Wed, Jul 20 2011
    • Posts 89
    • Points 1,270
    Re: How to find the Phase Noise for the DIVIDER Reply

     Dear Andrew,

    Thanks a lot for your reply.

    I am using MMSIM10 but I am not sure whether it is the latest one.

    However I couldn't find the NOISE OPTION in the ADE-SIMULATION-ANALOG-OPTIONS form.

    I wrote in OTHER OPTIONS section as suggested by you. I have attached the snapshot how I have entered.

    Could you please have a look at it and tell me whether it is correct.

    One more doubt:- Whether this take only INSTANCES ? 

                            I have a MOS in the schematic with name NM11. If I write, noiseoff_inst=[I561 NM11], will it be OK ?

    Kind Regards


    • Post Points: 5
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Started by RFQuery at 25 Mar 2012 08:57 PM. Topic has 4 replies.