Pspice or HSPICE coding for MOSFETs

[Aparna Anand]

Can anyone please tell what do we mean by LEVEL 1 or LEVEL 2 or LEVEL 3 and so on when we write the netlist in pspice or hspice while including mosfet models?

 

[keith1200rs]

They are models of increasing complexity to better represent true MOSFET behaviours.

LEVEL refers to the MOSFET model that describes
the terminal I-V characteristics of the
transistors. LEVEL 1 is the simplest Mosfet model
and is in general sufficient for describing
discrete transistors.
However to simulate integrated circuit transistors, one need to use a more
sophisticated models. LEVEL 2 includes
extensive second-order models, while LEVEL 3
is a semi-empirical model that is better suited
for short-channel transistors. Another model
that is especially suited to model short-channel effects is called the BSIM model (LEVEL 13 in
HSpice).

Keith

 

[Aparna Anand]

Thank you sir...

 

[Aparna Anand]

Hi everyone
Please help me with the delay measurement in HSPICE through graph as well as writing '.measure' command in the netlist.
I actually have the doubt that if we are taking two inputs A and B suppose in EXOR Gate and an output Y then how would the command be given?
Its something like-
.meas tran tdlay TRIG v(A) val=0.9 TD=0N Rise=1 TARG v(Y) val=0.9 TD=0N Fall=1
then how would the overall delay between input and output be measured?
Do we need to give two seperate commands like this...one for B and Y as well....and then taking the average....or there is some other procedure.
And i think i am not exactly clear with what delay is measured in digital circuits....is it overall delay between input and output...or something else..
Please explain...