Issue link: https://resources.pcb.cadence.com/i/1180526
PSpice A/D User Guide Monte Carlo and sensitivity (worst-case) analyses October 2019 602 Product Version 17.4-2019 © 2022 All Rights Reserved. Worst-case analysis This section discusses the analog worst-case analysis feature of PSpice A/D. 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 A/D reads the standard model parameter tolerance syntax specified in the .MODEL statement. For each model parameter, PSpice A/D 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.