Take your op amp from Pspice netlist to Allegro design sub-circuit

September 05, 2011 // By Don LaFontaine
Don LaFontaine of Intersil Corp. explains how to take your op amp from Pspice netlist to an Allegro design sub-circuit.


You just finished looking at the data sheet specifications for an op amp that looks like a good fit for your design. You want to run simulations on your design before you head into the lab to build up a proto type.

You see the manufacture of the op amp is offering a PSPICE model netlist in their data sheet, but you are not sure how to convert the PSPICE model netlist into a sub-circuit for your simulator. If your simulator is a Cadence Allegro simulator, then this article will take you through a step-by-step process to convert the data sheet netlist into a sub-circuit for simulations. If your simulator is another type then you will need to contact the vendor who makes the op amp for support or possibly use their limited online simulation tools for your analysis.

Intersil provides a PSPICE model for all their new low-speed and low-power precision op amps at the end of the data sheets. The PSPICE model netlist and netlist schematic are included in the data sheet, along with simulation vs. characterization curves to highlight the accuracy of the PSPICE models. [To find out more about the making of these models, reference application note AN1556 for details on the making of the PSPICE models.]

Copying the PSPICE netlist

Download the data sheet or the PSPICE netlist from the web. The data sheet or netlist will be in pdf format. Open the pdf document and right click to enable the select tool, if it is not already selected. This will enable you to then copy and paste the entire netlist into notepad. Name the file with the extension .MOD (not case sensitive). This file needs to be saved in a common directory with all the other files for this design.

Model editor

Open the Cadence model editor (Cadence SPB 16.2AMS SimulatorSimulation AccessoriesModel Editor) Note: The version of Cadence software used in this

Design category: