eldo_user

Monte Carlo Analysis
Local and Global Variations
variations of the (W, L) parameters. The resistors R1 and R2 will receive the same random
values for DLR and DW during the Monte Carlo sampling. These variables are defined as the 2-
dimensional vector (DLR, DW R ).
.TITLE RCWIRE_EXAMPLE
* CIRCUIT PARAMETERS (WITH VARIATIONS)
.PARAM VARL=0 LOT/UNIF=0.05U DEV/UNIF=0.1U
.PARAM VARW=0 LOT/UNIF=0.05U DEV/UNIF=0.1U
* CIRCUIT
I1 0 1 1M
I2 0 2 1M
R1 1 0 RESISTOR
R2 2 0 RESISTOR
.MODEL RESISTOR R LEVEL=3 W=3U L=3U RSH=100 DW=VARW DLR=VARL
.DC
.MC 1000
* EXTRACT
.EXTRACT DC LABEL=V1 V(1)
.EXTRACT DC LABEL=V2 V(2)
.END
The resistor R1 (respectively R2) will be associated to two independent random variables. This
defines four independent uniform random variables (DL R1 , DW R1 , DL R2 , DW R2 ). The random
sampling will be run with a joint probability distribution that is the product of six uniform
distributions.
The vector of random variables associated to this circuit is a 6-dimensional vector noted as:
Note that, in the output file (the .chi file), these parameters will be named as follows:
• The global variables (DL R , DW R ) will be associated to P(VARW), P(VARL).
• The local variations of the width and the length of the R1 resistor will be:
PEM(VARW,R1,R), PEM(VARL,R1,R).
• The local variations of the width and the length of the R1 resistor will be:
PEM(VARW,R2,R), PEM(VARL,R2,R).
See “Parameter Naming Conventions” on page 536 for a detailed description of these macros.
Eldo® User's Manual, 15.3 443