Issue link: https://resources.pcb.cadence.com/i/1180526
PSpice User Guide Monte Carlo and sensitivity (worst-case) analyses October 2019 590 Product Version 17.4-2019 © 1999-2019 All Rights Reserved. Worst-case analysis This section discusses the analog worst-case analysis feature of PSpice. The information provided in this section explains how to use worst-case analysis properly and with realistic expectations. Overview of worst-case analysis Worst-case analysis is used to find the worst probable output of a circuit or system given the restricted variance of its parameters. For instance, if the values of R1, R2, and R3 can vary by +10%, then the worst-case analysis attempts to find the combination of possible resistor values which result in the worst simulated output. As with any other analysis, there are three important parts: inputs, procedure, and outputs. Inputs In addition to the circuit description, you need to provide two pieces of information: ■ the parameter tolerances ■ a definition of what worst means You can set tolerances on any number of the parameters that characterize a model. Note: You can define models for nearly all primitive analog circuit parts, such as resistors, capacitors, inductors, and semiconductor devices. PSpice reads the standard model parameter tolerance syntax specified in the .MODEL statement. For each model parameter, PSpice uses the nominal, minimum, and maximum probable values, and the DEV and/or LOT specifiers; the probability distribution type (such as UNIFORM or GAUSS) is ignored. The criterion for determining the worst values for the relevant model parameters is defined in the .WC statement as a function of any standard output variable in a specified range of the sweep.