Hello,


    If i want to check the linearity of my opamp, how do i determine what sims of the following or otherwise should i conduct ??

   THD /  Rapid IP3 / IM3 / IM2 / IM5 ??

Mayank,

  If you mean Spectre RF Rapid IP3 analysis then it is really a
analysis rather than a measurement. It is probably better used
as a tool to
1) Debug where there is distortion in the design, along with the
   distortion summary
2) Identify the "worst-case" corners to investigate when you have a
   lot of corner conditions. Or the Monte Carlo seeds[runs] to
   investigate

  I would probably add Spurious Free Dynamic Range to the list of
measurements, if the target application is for data converters. One
other thing to consider for your list is test frequencies, loads, etc.
to be used for characterization.

                                                       Best Regards,

                                                         Sheldon