Simulation on different levels
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A component can have several models. The models for a component are differed by level characteristics. The model selection for the simulator must be controlled by the level dialog, since the simulator has to pick out just one model for each component.
Contents
Example application
Why several models?
The first simulations are usually used to examine only the fundamental characteristic of the circuit, without parasitic effects (e.g. connector capacities). Obviously the computation is quicker when using relatively simple models. The influence on parasitic effects must also be examined as soon as the idealized circuit works.
In this respect a connector should possess two models
Model with ohmic resistances for the contacts (Low frequency model: LEVEL = LOWFREQ).
Model with additional capacities between the contacts and ground (High frequency model: LEVEL = HIGHFREQ).
Two models are listed in the box "Models (Type)" of the models dialog. In each case the field Level is filled with LOWFREQ or HIGHFREQ. The designators LOWFREQ and HIGHFREQ are freely fixed! An unlimited number of properties with arbitrary names can be assigned to the level characteristics. An OpAmp could possess a simple model with controlled sources which has the property SIMPLEOPAMP in the level characteristics. The manufacturer models of OpAmps (modeled with transistors) could carry the level characteristic MANUFACTURERMODELS.
Which model will be used/selected by the simulator?
When opening the models dialog it will be automatically initialized to the model, which the simulator will use. The same will be done with a click on the button SimModel. The selection depends on the level characteristics of the models and on the settings in the level dialog.
Level dialog
Each level characteristic is listed in the dialog and associated with a trackbar. Several level settings with additional short information can be defined and stored. A certain level characteristic can be set to forbidden, not desired, insignificant, desired or necessary with its trackbar. TARGET3001 selects in each case the model with the best (appropriate) level characteristics for the simulator. TARGET3001 shows warnings, if a component only has models, which do not have a necessary level characteristic or otherwise, all models have a forbidden level characteristic.
The following level settings would be useful
Level 1: Info="Simulation without parasitic effects" with LOWFREQ=DESIRED HIGHFREQ=NOT DESIRED
Level 2: Info="Simulation with parasitic effects" with LOWFREQ=NOT DESIRED HIGHFREQ=DESIRED