eldo_user

Monte Carlo Analysis
Parameter Naming Conventions
In this case two random variables are obtained PP(VAR1,VARW) and PP(VAR2,VARW) with
global variations.
This use of the implicit rules should be avoided as much as possible. It is encouraged for users
to specify explicit DEV/LOT variations.
Macro P(.)
The macro P(.) has only one argument:
P(parameter_name)
and the associated random variable has global variations. Consider the following netlist
.PARAM VARL=0 LOT/UNIF=0.05U
.PARAM VARW=0 LOT/UNIF=0.05U
.PARAM BIAS=1M
I1 0 1 BIAS
I2 0 2 BIAS
R1 1 0 RESISTOR
R2 2 0 RESISTOR
.MODEL RESISTOR R LEVEL=3 W=3U L=3U RSH=100 DW=VARW DLR=VARL
The parameters VARL and VARW now have explicit LOT variations, and there are two
independent random variables P(VARL) and P(VARW).
Macro PEM(.)
If a DEV argument is added to the previous .PARAM definitions,
.PARAM VARL=0 LOT/UNIF=0.05U DEV/UNIF=0.02U
.PARAM VARW=0 LOT/UNIF=0.05U DEV/UNIF=0.02U
we will have six random variables in the Monte Carlo sampling:
• P(VARL) and P(VARW) the global components of the variations on the width and
length of resistors.
• PEM(VARW,R1,R) and PEM(VARL,R1,R) the local components of the variations on
the width and length of the resistor R1.
• PEM(VARW,R2,R) and PEM(VARL,R2,R) the local components of the variations on
the width and length of the resistor R2.
The syntax of the PEM(.) macro is defined as follows:
PEM(parameter_name, device_name, instance_parameter)
Eldo® User's Manual, 15.3 541