Subcircuit creating

LF411C operational amplifier macromodel subcircuit created using Parts release 4.01 on 06/27/89 at 08 19 (REV N/A)... 

The libraries that come with the Lite version of Capture contain a few parts for creating your own models out of subcircuits. However, several models have been added for this text so that you can download the most common types of subcireuit models. A list of the models is given in Table 7-2 ... 

We are now ready to create the subcircuit netlist for this circuit. Select File and then Save to save the circuit, and then select File and then Close to close the window. You should return to the project tree for this circuit. Expand all the branches of the tree ... 

Note in the above right screen capture that the text MEH OpAmp is selected. If the subcircuit name is not selected, click the LEFT mouse button on the text to select it. We can now create the subcircuit netlist. Select Tools and Create Netlist from the Capture menus ... 

Select the options Create a Subcircuit Format Netllst and View Output, and then click the Browse button ... 

Make sure that the path and filename are entered correctly in the box. When the settings are correct, click the OK button to create the subcircuit netlist. After a few moments, the netlist will be created and a window will open and display the netlist ... 

This netlist describes the circuit we created in Capture. Since we chose to create a subcircuit netlist, the second line of the file declares the netlist as a subcircuit. The name of the subcircuit is MEHjOpAlTip, or whatever you named your subcircuit, and the calling nodes are Vm, V0, and Vp. These node names were derived from the ports we added to the circuit. The order is not important because we will have Capture create the symbol for this subcircuit, and it will use the same nodes in the correct order. 

In the previous section, we created the netlist for our subcircuit. Next, we have to create a graphic symbol to place in our schematic. We will continue with the previous example where we are displaying the project tree. Note that the subcircuit name is still selected ... 

In the NetllSt file field, enter the name of the netlist we created in the previous section. You can use the Browse button to select the file we created. I named my netlist file C Program Files OrcadLite Capture Library PSpice User subcircuits.lib. 

The new. olb file is added to our project tree. We see that this library only contains one graphic symbol, the one we just created for our subcircuit. 

The last thing we need to do is configure Capture and PSpice to use the subcircuit and symbol libraries we created. Create a new blank project ... 

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