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Monte Carlo Analysis
Monte Carlo Analysis Examples
Monte Carlo Analysis Examples
This section contains the following examples of Monte Carlo Analysis:
A Simple Passive Low-Pass Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 526
Importance Sampling Monte Carlo Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528
Model-Based Approximations Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532
Further Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534
A Simple Passive Low-Pass Filter
You can easily see the effects of Monte Carlo analysis in a simple passive low-pass filter.
.MODEL C CAP DEV=20%
.MODEL R RES LOT=20% DEV=5%
.MC 1000 ALL
V1 VIN 0 AC=1 DC=1
R1 VIN A R 1k
C1 A 0 C 10P
.AC DEC 10 100 1e8
.PROBE V
.END
The capacitor model has uniform LOT variations with a half-range of 20%, so all capacitors
using this model are uncorrelated and vary up to 20% from the nominal value specified in the
element instantiation. Capacitor C1 varies uniformly between 8 pF and 12 pF. The resistor
model produces resistors such that the resistance values are correlated. After Eldo applies the
20% LOT variations, each resistor has a 5% non-correlated variations.
The .MC ... ALL argument requests Eldo to save the result from every Monte Carlo iteration.
Running this simulation and viewing the voltage at node A produces the graph in Figure 11-21.
526
Eldo® User's Manual, 15.3