I know the cd4049 is just two FET's but I don't know how I can model those transistors to be at least near what one would expect from the behavior of the IC.
Also, what parameters are absolutely needed when modelling a FET? Can I leave some out? I have seen different models with different complexity, that is confusing. I'm pretty new to modeling components in spice, in other words, this will be my first.
Ok, I found an excellent tutorial on how to do this using pspice.
They take PMOS and NMOS FETs' models and specify only the parameters that are different from those default. This is what I want to do, but how can I know the parameters of the FETs from the datasheet?.