SPICE
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Screen shot of Spice OPUS, a fork of Berkeley SPICE |
SPICE (Simulation Program with Integrated Circuits Emphasis) is a general purpose
analog circuit simulator.It is a powerful program that is used in
IC and board level design to check the integrity of
circuit designs and to predict
circuit behavior.
Integrated circuits, unlike board-level designs composed of discrete parts, are impossible to
breadboard before manufacture. Further, the high costs of photolithographic masks and other manufacturing prerequisites make it essential to design the circuit to be as close to perfect as possible before the integrated circuit is first built. Simulating the circuit with SPICE is the industry-standard way to verify circuit operation at the transistor level before committing to manufacturing an integrated circuit.
Board-level designs can often be breadboarded, but designers may want more information about the circuit than is available from a single mock-up. For instance, performance is affected by component values and it is helpful for designers to simulate with SPICE to predict the effect of variations of those values. Even with a breadboard, some aspects of operation may not be accurate compared to the final printed wiring board, such as parasitic resistances and capacitances. In
radio applications, especially
UHF and
microwave, parasitics are important and must be built into the model of the circuit being simulated. In these cases it is usual to perform
Monte Carlo simulations using SPICE, a task which is impractical using calculations by hand.
Circuit simulation programs, of which SPICE and derivatives are the most prominent, take a text
netlist describing the circuit elements (
transistors,
resistors,
capacitors, etc.) and their connections, and translate this description into equations to be solved. The general equations produced are nonlinear
differential algebraic equations which are solved using
implicit integration methods,
Newton's method and
sparse matrix techniques.
SPICE was originally developed at the Electronics Research Laboratory of the
University of California, Berkeley in 1975 by Larry Nagel and
Donald Pederson. Versions 1 and 2 were coded in
Fortran (2G.6 in
1983 was the last) and ran on
mainframe computers. Versions 3 and later are coded in
C, but still use a Fortran-like syntax for circuit description. Many commercial versions of SPICE have later replaced Berkeley SPICE as the industry standard. While many are still compatible with the original Berkeley syntax, commercial vendors added proprietary extensions that limit the portability of circuit descriptions and models between different vendors. Most recent versions also include a graphical user interface for constructing circuit descriptions. For digital circuits (e.g.,
RAM), dedicated simulators exist that run orders of magnitude faster than the traditional Spice tools.
SPICE was largely a derivative of the CANCER program presented by Ronald A. Rohrer announced in a paper at the 1971
ISSCC. CANCER was an acronym for "Computer Analysis of Nonlinear Circuits, Excluding Radiation," a hint to Berkeley's liberalism of 1960s: at these times many circuit simulators were developed under the
United States Department of Defense contracts that demanded the capability to evaluate the
radiation hardness of a circuit. The original SPICE program was released under a restrictive license, which makes it difficult for others to improve upon the original software. Berkeley SPICE continues to influence both commercial and academic offshoots of the program. A new circuit simulator,
Ngspice, based on SPICE 3F5, is licensed under the old BSD license. There also exists a branch project called tclspice. Free versions are available for non-commercial use for most computing platforms. LTSPICE is a free SPICE that works on
Microsoft Windows and on
Linux (under
Wine (software) emulator).
MacSpice is available for Mac OS9 and OSX.
First versions of Berkeley SPICE used
Nodal analysis. However this meant that ideal voltage sources and inductors could not be included in the circuit. Later versions are using
Modified nodal analysis, which does not have this drawback. Different algorithms are used to translate all circuit analysis problems into a single or multiple simpler problems of calculating an operating point of a linear circuit. Such problems can then be solved efficiently by solving a linear simultaneous equation. For example non-linear circuits are solved using a
Newton-Raphson algorithm, which linearizes non-linear elements in a circuit. Transient analysis is performed using trapezoid or Gear integration algorithm.
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MultiSIM (mixed-mode simulator with microcontroller simulation from
Electronics Workbench, now owned by
National Instruments)
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HSPICE (originally from
Meta Software, now owned by
Synopsys)
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PSPICE (originally from MicroSim, then
OrCAD, now by
Cadence Design Systems)
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SmartSpice (
Silvaco)
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T-Spice (
Tanner EDA)
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Spectre (general purpose SPICE replacement and RF simulator by
Cadence Design Systems)
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Eldo (A SPICE-like Analog-Mixed and RF simulator by
Mentor Graphics)
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UltraSim (FastSPICE tool by
Cadence Design Systems)
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LTspice Free simulator from Linear Technology*
NanoSim(FastSpice, originally by EPIC, now by
Synopsys)
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NSPICE (
Apache Design Solutions)
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HSIM (FastSpice, originally from
Nassda, now by
Synopsys)
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B2SPICE (Beige Bag)
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ICAP/4 (analog and mixed-signal circuit simulation by
Intusoft)
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TINA Design Suite DesignSoft's Tina Spice Simulator*
TINA-TI Free simulator based on DesignSoft's Tina Spice Simulator*
SPICE OPUS Spice Opus is a mixed-mode simulator with built-in optimization utilities.*
SIMetrix Schematic editor and simulator from Catena software*
Micro-Cap (
Spectrum Software)
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WinECAD (
a special french version by micrelec for educational market)
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edspice ( from
edwinxp owned by Visionics)
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ngspice*
tclspice*
IBIS (
Input Output Buffer Information Specification)
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Altium Designer*
OrCAD*
APLAC Analysis Program for Linear Active Circuits
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SPICE on gEDA HOWTO*
The Spice Page*
AboutSpice.com: A vendor independent information source for the Spice electronic simulation users*
A brief history of SPICE*
3D animation of SPICE simulations*
Spice 3 Userguide*
Spice 3 Quickstart Tutorial
