9 - SPICE Netlists

Abstract

This chapter describes how to capture a schematic and create a netlist for simulation program with integrated circuit emphasis (SPICE) circuit simulation. SPICE simulation programs, such as PSpice, require a circuit file as input. The circuit file consists of title line and comments, circuit device declarations list, and SPICE commands. Capture can extract SPICE commands, comments, and device declarations from special text strings placed on the schematic. SPICE text strings must be preceded by the pipe character (I). OrCAD provides a special PSpice parts library. PSpice and other SPICE versions as well, have certain special requirements and considerations regarding parts: special reference designators, device values and units, device models, and device pin names. The chapter discusses some basic considerations relevant to Capture. First, circuits for SPICE simulation can generally be simplified such as SPICE voltage sources for power supplies are ideal, with zero source impedance. Second, simple passive circuit devices such as resistors and capacitors are modeled as ideal devices without parasitic elements. Parameters such as resistor wattage or capacitor polarity and rated voltage are not applicable to the ideal devices modeled in SPICE.