SPICE Export

The functionality creates a SPICE netlist file containing a description of the circuit represented by the physics interface. This functionality can be accessed from the physics interface context menu (right-click the physics interface node and select ). After specifying a filename, the circuit is exported and messages from the export process display in the window. During the export process, a series of operations are performed:

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In order to avoid conflicts, each component must be identified by a unique . If one or more components have the same device name, the export operation fails and an error message is displayed. All characters in a that are not letters, digits, or underscores are replaced by underscores.

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According to the SPICE specification, each circuit must have a node with name 0, which is assumed to be the only ground node. When exporting a circuit, any node with name 0 that is not connected to a component is exported with a different node name. All nodes that are connected to a Ground components are exported as a merged node with name 0. The Messages window shows a log message if these operations are performed, showing the name of the renamed or merged nodes.

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All characters in node names that are not letters, digits, or underscores are replaced by underscores.

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Some components (most notably, the components used to couple to other physics interfaces) cannot be exported to a SPICE netlist. These components are ignored during the export process, and a message is shown in the Messages window. Note that this can change the exported circuit, since some components are then missing.

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Subcircuit definitions are added as .subckt statements in the netlist. Semiconductor devices (such as MOSFETs, BJTs, and diodes) are exported as a SPICE device with a corresponding .model statement.

The title of the exported netlist file is the model’s filename, and the time, date, and version of COMSOL Multiphysics is added as a comment in the netlist file.