Issue link: https://resources.pcb.cadence.com/i/1180526
PSpice User Guide Creating and editing models October 2019 189 Product Version 17.4-2019 © 1999-2019 All Rights Reserved. What are models? A model defines the electrical behavior of a part. On a schematic page, this correspondence is defined by the Implementation property on the part, which is assigned the model name. Depending on the device type that it describes, a model is defined as one of the following: ■ a model parameter set ■ a subcircuit netlist Both ways of defining a model are text-based, with specific rules of syntax. Models defined as model parameter sets PSpice has built-in algorithms or models that describe the behavior of many device types. The behavior of these built-in models is described by a set of model parameters. You can define the behavior for a device that is based on a built-in model by setting all or any of the corresponding model parameters to new values using the PSpice .MODEL syntax. For example: .MODEL MLOAD NMOS + (LEVEL=1 VTO=0.7 CJ=0.02pF) Note: In addition to the analog models built into PSpice, the .MODEL syntax applies to the timing and I/O characteristics of digital parts. Models defined as subcircuit netlists For some devices, there are no PSpice built-in models that can describe their behavior fully. These types of devices are defined using the PSpice .SUBCKT/.ENDS or subcircuit syntax instead. Subcircuit syntax includes: ■ Netlists to describe the structure and function of the part. ■ Variable input parameters to fine-tune the model. For example: