SPICE Program for Electronic Circuits
SPICE (Simulation Program with Integrated Circuit Emphasis) is a general-purpose program for representing analog electronic circuits. Schematic diagrams representing active RC networks and passive network topologies are drawn using a combination of SPICE data statements and graphical drawing elements. The Rausch filter circuit schematic is used as the illustration.[more]
The reader should be aware that this Demonstration will require a commitment of significant time and effort to produce useful results.[less]
The SPICE data statement is used to describe the electronic component and the nodal connections. A data statement is entered as a single line by using the Demonstration keypad, followed by a mouse click on the work surface to identify the location assigned to the data statement.
Integer numbers are used for the following fields: "name", N+, N-, N1, N2, and N3.
Either integer or floating-point numbers are used for Value, DCValue, and ACValue.
Each field is separated by a "space."
A mouse click on the working surface determines the location of either the SPICE component or the graphical element.
Components and drawing elements have designated hot spots on the drawing surface, which allow the targeted item to be selected or deselected by alternating mouse clicks. A selected component appears as a SPICE data statement in the statement field, whereas a selected node, track, or ground is indicated in red.
Popup menu: Used to select SPICE entry mode, or graphical elements.
"Clear" button: Clears work surface.
"Delete" button: Deletes SPICE component currently displayed in the statement field or deletes graphical element currently displayed in red.
"Flip X" button: Flips a selected SPICE component on the horizontal axis.
"Flip Y" button: Flips a selected SPICE component on the vertical axis.
"Rotate" button: Rotates either a selected SPICE component or a selected ground graphic by 90 degrees.
Keypad: Provides for entry and editing of a SPICE data statement. A complete data statement is entered prior to setting the location with a mouse click.
Current reference arrows follow the passive sign convention (PSC).
Snapshot 1: second-order passive bandpass filter
Snapshot 2: second-order active bandpass filter
Snapshot 3: passive resistor network with multiple DC voltage supplies
The node drawing element marked with a cross is used to designate a node connected to either a dependent or independent voltage source. The remaining nodes not designated as cross nodes are functionally described by Kirchhoff's current law.
Reference (for cross node)
 J. Vlach and K. Singhal, Computer Methods for Circuit Analysis and Design, 2nd ed., Norwell, MA: Kluwer Academic Publishers, 2003 pp. 144–155.