Simulations are set up by specifying the desired parameters for them in the Simulation Environment view.

About this task​

Setting up a simulation includes specifying the desired result categories, simulation parameters, and output options. While it is possible to run a simulation with default settings, getting the information required in a particular stage of the development usually requires an appropriate setup for the simulation.

Specifying a setup includes entering numerous values. Options for doing so are described in

Values and expressions

.

Before you begin​

The circuit that you want to simulate must be available in the project as a schematic.

Procedure​

  1. Open the schematic to be simulated.

    The tab displaying it must be the frontmost tab.

  2. In the

    Simulation Environment

    view’s

    Analyses

    tab, check the areas that the simulation should analyze.

    For each of the areas – transients, operating points, DC, AC – a subtab is displayed where you can specify basic settings for the analysis.

    These settings are explained in detail in

    Simulation Environment view

    .

    Note that an AC analysis requires the power source of the schematic to have an ACM setting.

  3. Specify the desired accuracy and temperature at the bottom of the

    Analyses

    tab.

    Note that higher accuracy slows down the simulation. What SPICE settings correspond to each choice is displayed when you hover the mouse over the corresponding radio button.

  4. In the

    Parameters

    tab, specify the settings for any parameters that you have defined.

    Any values that depend on parameters (see

    Values and expressions

    ) are calculated for the simulation using the parameter settings in this tab.

    For example, when a value is specified as as

    2*baseRate+1

    and

    baseRate

    is set to 5, the value is 11 during this simulation. If you set

    baseRate

    to 5.5, the value calculated from it is 12.

    Note that the value assigned to a parameter can be static values or expressions (see

    Values and expressions

    ) and can include other parameters.

  5. In the

    Plot Setup

    tab, specify which voltages and currents are recorded for evaluation.

    All

    Every voltage or current, including in subcircuits

    Top-level

    Every voltage or current in the schematic itself, but not those in subcircuits

    Signal only

    Only voltages or currents on the specified signal

    Recording more voltages or currents gives you more flexibility in the evaluation of the simulation, but the simulation takes longer to run.

    You can define additional signals in the schematic using the Select Output tools

    and

    (standard and differential, respectively). You can also define expressions to plot based on signals by double-clicking the

    New expression

    entry, which opens the

    Expression

    dialog.

  6. From the tab’s

    Plot Mode

    list, choose how the simulation results are to be displayed.

    This setting determines just the initial display of the results. You can always add, remove, and rearrange plots during evaluation. For details, see

    Working with plots

    .

  7. If external libraries for subcircuits in the schematic are required, specify them in the

    Model Libraries

    tab.

    Enter the path of each library file, either as an absolute path or a relative path.

  8. In the

    Settings

    tab, specify how floating nodes are to be handled.

    By default, a floating node is handled as if it were connected to ground through a 1 GΩ resistor.

  9. If you want to add custom netlist commands to the simulation, enter them In the

    Additional Netlist Commands

    tab.

    Any netlist code you enter here is appended to the end of the netlist that

    InfineonSpice

    creates for the simulation.

Results​

The simulation is now ready to run.

What to do next​

You can run the simulation, as described in

Running a simulation

.