Creating Schematic-Based Subcircuit Models

1. Starting with a working schematic (.sxsch file), use File > Save As... to save the schematic as a component (.sxcmp file).

   

2. Define the subcircuit terminals, found under Place > Hierarchy > Module Port.

   

   The example fuse circuit defines three module ports: Fuse_IN, Fuse_OUT, and I2t.

   

   Please note that is not required and rarely a good idea to place an explicit ground symbol inside this kind of subcircuit. This example is an exception, as all active terminals are carefully isolated and only the measurement terminal is referenced to ground, allowing the use of a single ended voltage probe.

3. Use Hierarchy > Open/Create Symbol for Schematic... to create a symbol to represent the subcircuit in higher level schematics.

   

   This will automatically launch the Symbol Editor with a default symbol with a pinout corresponding to the module ports in the schematic.

   

4. Use Property/Pin > Edit Properties... to edit the properties of the new symbol.

   

   Edit the individual properties to determine their visibilty and placement on the schematic. Add any properties required by your subcircuit parametrization needs. For this simple example, no additional parameters are necessary.

   

5. Use the drawing tools of the Symbol Editor to customize the appearance of the symbol.

   

6. Use File > Save... in the Symbol Editor to save the subcircuit symbol as part of the .sxcmp file.

   

7. To place an instance of the new component in a top level schematic, use either Hierarchy > Place Component (Full Path)... or Hierarchy > Place Component (Relative Path).... In general, use of relative paths is recommended.

   

   The Open Symbol dialog will appear allowing selection of the .sxcmp file representing the subcircuit.

   

8. Place an instance of the component on the schematic.

   

9. Finally, draw the appropriate wires to connect the symbol to the circuit.