SPICE (software)

SPICE (software)
Name	SPICE
Developer	Jet Propulsion Laboratory
Released	0 1975
Programming language	Fortran, C
Operating system	Unix, Linux, macOS, Microsoft Windows
Genre	Electronic circuit simulation

SPICE (software). SPICE is a general-purpose, open-source electronic circuit simulation program used extensively in integrated circuit and printed circuit board design. Developed at the Jet Propulsion Laboratory under the direction of Laurence Nagel, it has become the industry standard for analog circuit analysis. The software enables engineers to predict the behavior of electronic circuits without physically building them, significantly accelerating the design process for complex systems.

Overview

SPICE simulates the electrical behavior of circuits composed of components like resistors, capacitors, inductors, and semiconductor devices including diodes and transistors. Its core function is to solve the nonlinear differential algebraic equations that describe circuit operation using techniques such as modified nodal analysis. The program performs various analyses, including DC analysis, transient analysis, and AC analysis, providing critical data on voltage, current, and power dissipation. This capability is fundamental for designing everything from microprocessors to radio frequency amplifiers, ensuring functionality and reliability before silicon fabrication.

History and development

The project originated in the early 1970s at the University of California, Berkeley under professor Donald Pederson as part of the CANCER (software) program. Laurence Nagel and Ellis Cohen later rewrote and refined the code at the Jet Propulsion Laboratory, releasing the first official version, SPICE1, in 1975. Subsequent major releases, including SPICE2 and the widely influential SPICE3 developed by Thomas Quarles, introduced more sophisticated semiconductor models and a C codebase. Its adoption was propelled by its public domain status and its critical role in the design automation revolution, supported by agencies like the Defense Advanced Research Projects Agency.

Technical architecture

The software employs a netlist-based input describing circuit topology and component values. Its simulation engine constructs a system of equations representing Kirchhoff's circuit laws and solves them using numerical methods like the Newton–Raphson method and LU decomposition. A key innovation is its use of Berkeley SPICE device models, such as the Shichman–Hodges model for MOSFETs, which balance accuracy and computational efficiency. The architecture is modular, separating the parser, numerical solver, and output processor, allowing for extensibility and the integration of new device models and analysis types.

Applications and usage

SPICE is indispensable in the electronics industry for designing and verifying analog integrated circuits, mixed-signal integrated circuits, and power electronics. It is used to analyze signal integrity, crosstalk, and electromagnetic interference in printed circuit board layouts. Beyond commercial semiconductor companies, it is a vital educational tool in university courses like those at the Massachusetts Institute of Technology and Stanford University. The software also supports the development of photonics devices and microelectromechanical systems, and its algorithms underpin many commercial electronic design automation tools from vendors like Cadence Design Systems and Synopsys.

File formats and data models

The primary input format is a plain-text SPICE netlist with extensions like `.cir` or `.sp`. This file defines circuit elements, nodes, and simulation commands using a syntax standardized by Berkeley SPICE. Output is typically generated in raw data formats, which can be processed for graphical plotting. The software supports industry-standard semiconductor model parameter sets, such as those defined by the Compact Model Coalition, including BSIM for advanced CMOS technologies. These data models are crucial for accurate simulation of deep-submicron effects in modern integrated circuit manufacturing processes.

Related software and integrations

Numerous commercial and academic variants have been derived from the original Berkeley SPICE codebase. These include HSPICE from Synopsys, PSPICE from Cadence Design Systems, and LTspice from Analog Devices, each adding proprietary optimizations and user interfaces. The core algorithms are also embedded within larger electronic design automation suites like the Cadence Virtuoso platform. Open-source projects like ngspice and Gnucap continue its legacy, while its simulation methods influence tools in related fields such as Synopsys Sentaurus for technology computer-aided design.

Category:Electronic circuit simulators Category:Free science software Category:Jet Propulsion Laboratory Category:1975 software