Issue link: https://resources.pcb.cadence.com/i/1180526
PSpice User Guide Creating and editing models October 2019 206 Product Version 17.4-2019 © 1999-2019 All Rights Reserved. the part of the current equation that is associated with the forward characteristic parameters (such as IS, N, Rs). However, PSpice uses the full equation for the diode model, which includes a term involving the reverse characteristic parameters (such as ISR, NR). These parameters could have a significant effect at low current. This means that the curve displayed in the Model Editor does not exactly match what is displayed in PSpice after a simulation. Be sure to test and verify models using PSpice. If needed, fine-tune the models. Creating models from data sheet information The most common way to characterize models is to enter data sheet information for each device characteristic. After you are satisfied with the behavior of each characteristic, you can have the Model Editor estimate (or extract) the corresponding model parameters and generate a graph showing the behavior of the characteristic. This is called the fitting process. You can repeat this process, and when you are satisfied with the results, save them; the Model Editor creates model libraries containing appropriate model and subcircuit definitions. Note: When specifying operating characteristics for a model, you can use typical values found on data sheets effectively for most simulations. To verify your design, you may also want to use best- and worst-case values to create separate models, and then swap them into the circuit design. Analyzing the effect of model parameters on device characteristics You can also edit model parameters directly and see how changing their values affects a device characteristic. As you change model parameters, the Model Editor recalculates the behavior of the device characteristics and displays a new curve for each of the affected ones.