[SOLVED] what's the difference between TT FF and SS Model?

[prcken]

hey, can u tell me what's the difference between TT FF and SS Model in spice library?
i know some of norminal values of the parameters are different, but still dont figure out why it's called TT or FF....? the name is concerned as the speed or some other reasons?
can you give me an explicit explaination?
thanks!

 

[Fom]

TT: typical NMOS, typical PMOS
FF: fast NMOS, fast PMOS
SS: slow NMOS, slow PMOS
except these 3 corners there may be additional 2
FS: fast NMOS, slow PMOS
SF: slow NMOS, fast PMOS

 

[prcken]

i know what these words stand for, could you tell me why we need to split the model into diffferent forms, Fast or Slow means speed or has some other meaning? why it's call fast and why it's named slow?
thx!

 

[Fom]

Yes, Fast and Slow means speed or propagation delay in digital components. For Fast propagation delay smaller for Slow propagation is larger. All model parameters for SLOW models deviate so that delay will be larger.

 

[prcken]

i see ~~
just have a general idea of it