Spectrum Software
Industrial Strength Simulation




Spectrum Software has released Micro-Cap 11, the eleventh generation of our SPICE circuit simulator.

For users of previous Micro-Cap versions, check out the new features available in the latest version. For those of you who are new to Micro-Cap, take our features tour to see what Micro-Cap has to offer.




Questions and Answers - Spring 2009


Question 1: How do I define a tolerance on a battery component so I can run Monte Carlo simulations on my circuit?

Answer: Typically the only objects that can have a tolerance assigned to them are define variables and parameters within model statements. There are a couple of exceptions and tolerancing a battery is one of them. Assigning a tolerance to a battery is simple. In the VALUE attribute of the battery, enter the LOT statement after the voltage value of the battery. The syntax for defining the value of a battery is:

<value> [LOT[/<lot#>][/<distribution name>]=<value>[%]]

<lot#> optionally specifies which of one hundred random number generators, numbered 0 through 99, are used to calculate parameter values. This lets you correlate parameters among different components.

<distribution name> optionally specifies the distribution as follows:

UNIFORM = Equal Probability distribution
GAUSS = Normal or Gaussian distribution
WCASE = Worst case distribution

As an example, if you would like to enter a 10V battery that has a tolerance of 20%, the VALUE attribute for the battery component would be defined as:

10 LOT=20%

Most of the parameters in the Voltage Source and Current Source components can also be toleranced in a similar manner.

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