Perhaps no single development has had as much impact on the microelectronics industry as the SPICE (Simulation Program with Integrated Circuit Emphasis) program, which originally was developed by Laurence Nagel during his graduate studies at the University of California, Berkeley. SPICE and its subsequent enhancements moved mainstream circuit design from empirical, bread-board-based design into the era of scientifically based simulation and modeling. Nagel incorporated both direct current and alternating current analysis; transient analysis; and, based on adjoint network theory and sparse matrix techniques, efficient sensitivity, noise, and distortion analysis. SPICE was made freely available from the start and was widely adopted by universities, allowing students to learn how circuits work without having to build them and to easily evaluate design alternatives. Today's multibillion-transistor ICs, especially mixed-signal and precision analog ICs, would be impossible without the detailed circuit simulation that SPICE provides.
An IEEE Life Fellow, Nagel is president of Omega Enterprises Consulting, Kensington, CA, USA.