Attaching a SPICE RLC Model to a Component in HFSS 3D Layout

You can attach a SPICE RLC model to a specific component in the layout or to a component type in multiple ways. This model can include an arbitrary Netlist when the component's Solve Independent option is enabled (i.e., selected for inclusion by Linear Network Analysis only).

1. From the SIwave Workflow Wizard:
   1. From the Layout tab, click Workflow to open the wizard.
   2. Click Assign SPICE Netlists.
2. From the Properties window:
   1. From the Layout Editor, click a component.
   2. From the Properties window, click the button in the Model Info row.
   3. From the Component Model window, click SPICE model on the Type drop-down menu.
   4. Click Import SPICE Model to open the RLC SPICE Model Setup window.

   

3. Select the Part Name to display its Pin Layout.
4. To see the net assignments for the component’s pins, check the Display net names for ref. des. check box.
5. Select the Model:
   1. Choose a model on the drop-down menu, or click Create to create a new one.

      The Create RLC SPICE Model window opens, showing the same Model name as the Part Name.

      

   2. Type the name and location of a SPICE netlist, or
   3. Click Browse to locate a file you want to attach to the selected part.

      The model name is now set to the SPICE subcircuit name, but can be edited.

6. Click OK to close the Create RLC SPICE Model window

If coming on the Component Model window, you are done.

If coming on the SIwave Workflow Wizard, the selected model is loaded and the terminals in the SPICE subcircuit display. Continue as follows.

7. Map Terminals in the SPICE subcircuit to corresponding Pins belonging to the part.
   Note:

   Mapping must be performed correctly, as simulation results depend on proper connections between part pins and the SPICE subcircuit terminals.

8. Assign the SPICE model, in the SPICE Model Assignment area:
1. Select a Part Number and Reference Designator.
2. Make a selection on the SPICE Model drop-down menu.
3. Select the Model Active check box if you want to assign a model and want it to be active. If cleared, the model is assigned but is not active.
9. If you want to assign the same SPICE model and model active settings to multiple parts:
1. Select the reference designators to which you want to assign the same SPICE model. You can select multiple reference designators in the table using Ctrl and Shift, or select all using Ctrl +A.
2. Select the SPICE model on the dropdown menu.
3. Click Update.
4. To activate the model for all the selected parts, select Yes on the Model is Active? drop-down menu, and click Update.
10. Click Save to save the model and open the Select Spice Model Assignment Output File Name window. Select the location to store the saved file. Enter the name for the file in the File name field. Select the file type on the Save as type area. You can save files with .smas (Spice Model Assignment File) extensions. Click Save.
11. Click Load to load the saved values from a file and open the Select Spice Model Assignment File to load window. Select the file you want to open. You can open saved .smas files. Click Open.
12. To confirm the SPICE model assignments and return to the SIwave Workflow Wizard, click OK.

To indicate the connection of a SPICE model, a gray rectangle containing an X is displayed over the reference designator(s) in the Modeling workspace:

To activate or deactivate the SPICE model in the Properties window, click Model Info and set the Component ModelInterface to SPICE Model.