+ Post New Thread
Results 1 to 3 of 3
  1. #1
    Full Member level 6
    Points: 2,120, Level: 10

    Join Date
    Apr 2017
    Posts
    325
    Helped
    12 / 12
    Points
    2,120
    Level
    10

    Sample and Hold/Track and Hold Simulation in Cadence Spectre

    Hello,

    I am simulating track and hold/sample and hold in Cadence Spectre.

    Structure is simple TGATE or NMOS with sample capacitor. Schematic attached.

    Fin=50MHz
    FS=2GHz.

    I want to measure the SFDR and the THD of this structure.

    Do I use transient analysis or do I need to use PSS ?

    If transient, what is the setup of the strobe period and the DFT ?
    If PSS, what is the setup of the PSS settings ?

    I am using IC5.14 of Cadence Spectre so I do not have the Spectrum Assistant available as in IC6.17.

    Thank you.
    Last edited by Puppet123; 11th March 2020 at 17:53.

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 3
    Points: 11,164, Level: 25

    Join Date
    Nov 2001
    Location
    US
    Posts
    997
    Helped
    379 / 379
    Points
    11,164
    Level
    25

    Re: Sample and Hold/Track and Hold Simulation in Cadence Spectre

    Use transient. Take samples of the output at the end of your hold phase. Use conservative settings. Use number of cycles of the input sine wave and number of points for the dft N that conform to the formula Fin = (cycles/N)*Fs. Chose cycles and N mutually prime numbers.


    1 members found this post helpful.

    •   AltAdvertisement

        
       

  3. #3
    Full Member level 6
    Points: 2,120, Level: 10

    Join Date
    Apr 2017
    Posts
    325
    Helped
    12 / 12
    Points
    2,120
    Level
    10

    Re: Sample and Hold/Track and Hold Simulation in Cadence Spectre

    So, if I want to measure the SFDR or Dynamic Range in general, it is the same procedure as usual - run a transient, set the strobe period in options and as you said, make sure I have coherent sampling ? Is that correct ?

    - - - Updated - - -

    Also, I want to find the IIP3 of this filter.

    I want to run a two tone test with Vin at 10mv and 100mV.

    Do I use PSS/PAC or QPSS in Cadence Spectre ?

    Thanks.



--[[ ]]--