Editing SPICE

{{Short description|Open source analog electronic circuit simulator}}
{{other uses|Spice (disambiguation)}}

{{Infobox software
| title = SPICE 1
| logo = 
| screenshot = 
| caption = 
| author = [[:de:Larry Nagel|Laurence Nagel]]
| developer = 
| released = {{Start date and age|1973}}
| discontinued = Yes
| latest release version = 
| latest release date = <!-- {{Start date and age|yyyy|mm|dd}} -->
| programming language = [[Fortran]]
| operating system = 
| platform = 
| size = 
| language = English
| genre = [[Electronic circuit simulation]]
| license = [[Public-domain software|Public domain]]
}}
{{Infobox software
| title = SPICE 2
| logo = <!-- no File: -->
| screenshot = <!-- no File: -->
| caption = 
| author = 
| developer = 
| released = {{Start date and age|1975}}
| discontinued = Yes
| latest release version = 2G.6
| latest release date = {{Start date and age|1983}}
| programming language = [[Fortran]]
| operating system = 
| platform = 
| size = 
| language = English
| genre = [[Electronic circuit simulation]]
| license = [[BSD licenses#3-clause license|BSD 3-clause]]
}}
{{Infobox software
| title = SPICE 3
| logo = <!-- no File: -->
| screenshot = <!-- no File: -->
| caption = 
| author = Thomas Quarles
| developer = 
| released = {{Start date and age|1989}}
| discontinued = 
| latest release version = 3f.5
| latest release date = {{Start date and age|1993|07}}
| programming language = [[C (programming language)|C]]
| operating system = 
| platform = 
| size = 
| language = English
| genre = [[Electronic circuit simulation]]
| license = [[BSD licenses#2-clause|BSD 2-clause]]
| website = [https://web.archive.org/web/20231208045915/http://bwrcs.eecs.berkeley.edu/Classes/IcBook/SPICE/ Archived webpage]
}}

'''SPICE''' ('''Simulation Program with Integrated Circuit Emphasis''')<ref name=spice1>{{cite tech report |last1=Nagel |first1=Laurence W. |last2=Pederson |first2=D. O |url=http://www.eecs.berkeley.edu/Pubs/TechRpts/1973/22871.html |title=SPICE (Simulation Program with Integrated Circuit Emphasis) |number=UCB/ERL M382 |publisher=University of California, Berkeley |date=April 1973}}</ref><ref name=spice2>{{cite tech report |last=Nagel |first=Laurence W. |title=SPICE2: A Computer Program to Simulate Semiconductor Circuits |number=UCB/ERL M520 |publisher=University of California, Berkeley |date=May 1975 |url=https://www.eecs.berkeley.edu/Pubs/TechRpts/1975/9602.html}}</ref> is a general-purpose, [[open-source software|open-source]] [[Analogue electronics|analog electronic circuit]] [[Electronic circuit simulation|simulator]].
It is a program used in [[integrated circuit]] and board-level design to check the integrity of [[circuit design]]s and to predict [[Electronic circuit|circuit]] behavior.

== Introduction ==
Unlike board-level designs composed of discrete parts, it is not practical to [[breadboard]] integrated circuits before manufacture. Further, the high costs of [[Photomask|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. The SPICE simulators help to predict the behavior of the IC under different operating conditions, such as different voltage and current levels, temperature variations, and noise.<ref>BTV [https://besttechviews.com/spice-simulators-reviews-metrics/ SPICE Simulators.] Retrieved January 2, 2023</ref>

Board-level circuit designs can often be breadboarded for testing. Even with a breadboard, some circuit properties may not be accurate compared to the final printed wiring board, such as [[Parasitic element (electrical networks)|parasitic resistances and capacitances]], whose effects can often be estimated more accurately using simulation. Also, designers may want more information about the circuit than is available from a single mock-up. For instance, circuit performance is affected by component manufacturing tolerances.  In these cases it is common to use SPICE to perform [[Monte Carlo method|Monte Carlo]] simulations of the effect of component variations on performance, a task which is impractical using calculations by hand for a circuit of any appreciable complexity.

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<ref>{{cite journal |first=Colin |last=Warwick |url=http://www.nutwooduk.co.uk/pdf/Issue82.PDF#page=27 |journal = EMC Journal |issue = 82 |pages = 27–29 |date = May 2009 |title = Everything you always wanted to know about SPICE* (*But were afraid to ask) |format = PDF}}</ref> this description into equations to be solved.  The general equations produced are [[nonlinear system|nonlinear]] [[differential algebraic equation]]s which are solved using [[Explicit and implicit methods|implicit integration methods]], [[Newton's method]] and [[sparse matrix]] techniques.

== Origins ==
SPICE was developed at the Electronics Research Laboratory of the [[University of California, Berkeley]] by Laurence Nagel with direction from his research advisor, Prof. [[Donald Pederson]]. SPICE1 is largely a derivative of the CANCER program,<ref>{{cite journal |last1= Nagel |first1= L. W. |last2= Rohrer |first2= R. A. |title= Computer Analysis of Nonlinear Circuits, Excluding Radiation |journal= IEEE Journal of Solid-State Circuits |volume= 6 |date= August 1971 |issue= 4 |pages= 166–182 |doi= 10.1109/JSSC.1971.1050166 |bibcode= 1971IJSSC...6..166N}}</ref> which Nagel had worked on under Prof. Ronald Rohrer. CANCER is an acronym for "Computer Analysis of Nonlinear Circuits, Excluding Radiation".<ref>[http://www.designers-guide.org/Perspective/life-of-spice.pdf Life of SPICE] {{webarchive |url=https://web.archive.org/web/20120204190147/http://www.designers-guide.org/Perspective/life-of-spice.pdf |date=February 4, 2012 }}</ref> At these times many circuit simulators were developed under contracts with the [[United States Department of Defense]] that needed the ability to evaluate the [[radiation hardness]] of a circuit. When Nagel's original advisor, Prof. Rohrer, left Berkeley, Prof. Pederson became his advisor. Pederson insisted that CANCER, a proprietary program, be rewritten enough that restrictions could be removed and the program could be put in the [[public domain]].<ref>{{cite journal |last= Perry |first= T. |title= Donald O. Pederson |journal= IEEE Spectrum |date= June 1998 |pages= 22–27 |doi= 10.1109/6.681968 |volume= 35 |s2cid= 51633338 |url= <!-- http://www.designers-guide.org/dop1998.pdf -->}}</ref>

SPICE1 was first presented at a conference in 1973.<ref name=spice1/> SPICE1 is coded in [[FORTRAN]] and to construct the circuit equations uses [[nodal analysis]], which has limitations in representing inductors, floating voltage sources and the various forms of controlled sources.<ref name="vladimirescu94">{{cite book |last1=Vladimirescu |first1=Andrei |title=The SPICE Book |date=1994 |publisher=John Wiley & Sons, Inc. |location=New York}}</ref> SPICE1 has relatively few circuit elements available and uses a fixed-timestep [[transient analysis]]. The real popularity of SPICE started with SPICE2 in 1975.<ref name=spice2/> SPICE2, also coded in FORTRAN, is a much-improved program with more circuit elements, variable timestep transient analysis using either the trapezoidal (second order [[Adams-Moulton method]]) or the Gear integration method (also known as [[Backward differentiation formula|BDF]]), equation formulation via [[modified nodal analysis]] (avoiding the limitations of nodal analysis),<ref>{{cite journal |last1=Ruehli |first1=A. |last2=Brennan |first2=P. |title=The modified nodal approach to network analysis |journal=IEEE Transactions on Circuits and Systems |date=June 1975 |volume=22 |issue=6 |pages=504–509 |doi=10.1109/TCS.1975.1084079}}</ref> and an innovative FORTRAN-based memory allocation system.<ref>{{cite web |url=https://ltwiki.org/index.php?title=Recollections_of_the_%22The_Father_of_SPICE%22_Larry_Nagel |title=Recollections of the "The Father of SPICE" Larry Nagel |publisher=ltwiki.org |access-date=2024-02-21}}</ref> 
Ellis Cohen led development from version 2B to the industry standard SPICE 2G6, the last FORTRAN version, released in 1983.<ref>{{cite web |url=http://www.omega-enterprises.net/The%20Origins%20of%20SPICE.html |title=The Origins of SPICE |first1=Laurence W. |last1=Nagel |publisher=omega-enterprises.net |access-date=2024-02-21}}</ref><ref name=pederson84>Pederson, D.O. January 1984. "A Historical Review of Circuit Simulation." IEEE Transactions on Circuits and Systems, vol pp103-111.</ref> SPICE3 was developed by Thomas Quarles (with [[A. Richard Newton]] as advisor) in 1989. It is written in [[C (programming language)|C]], uses the same netlist syntax, and added [[X Window System]] plotting.<ref>Quarles, Thomas L., ''Analysis of Performance and Convergence Issues for Circuit Simulation'', Memorandum No. UCB/ERL M89/42, University of California, Berkeley, April 1989.</ref>

As an early [[public domain software]] program with [[source code]] available,<ref>[http://www.allaboutcircuits.com/textbook/reference/chpt-7/history-of-spice/ history-of-spice] {{webarchive |url=https://web.archive.org/web/20161009084508/http://www.allaboutcircuits.com/textbook/reference/chpt-7/history-of-spice/ |date=October 9, 2016 }} on allaboutcircuits.com. "The origin of SPICE traces back to another circuit simulation program called CANCER. Developed by professor Ronald Rohrer of U.C. Berkeley along with some of his students in the late 1960s, CANCER continued to be improved through the early 1970s. When Rohrer left Berkeley, CANCER was re-written and re-named to SPICE, released as version 1 to the public domain in May of 1972. Version 2 of SPICE was released in 1975 (version 2g6—the version used in this book—is a minor revision of this 1975 release). Instrumental in the decision to release SPICE as a public-domain computer program was professor Donald Pederson of Berkeley, who believed that all significant technical progress happens when information is freely shared. I for one thank him for his vision."</ref> SPICE was widely distributed and used. Its ubiquity became such that "to SPICE a circuit" remains synonymous with circuit simulation.<ref>{{cite web |last=Pescovitz |first=David |date=2002-05-01 |title=1972: The release of SPICE, still the industry standard tool for integrated circuit design |url=http://www.coe.berkeley.edu/labnotes/0502/history.html |url-status=dead |archive-url=https://web.archive.org/web/20150709211311/http://www.coe.berkeley.edu/labnotes/0502/history.html |archive-date=2015-07-09 |access-date=2007-03-10 |website=Lab Notes: Research from the Berkeley College of Engineering}}</ref> SPICE source code was from the beginning distributed by UC Berkeley for a nominal charge (to cover the cost of magnetic tape). The license originally included distribution restrictions for countries not considered friendly to the US, but the source code is currently covered by the [[BSD license]].

The birth of SPICE was named an [[List of IEEE milestones|IEEE Milestone]] in 2011; the entry mentions that SPICE "evolved to become the worldwide standard integrated circuit simulator".<ref>{{cite web |url=http://www.ieeeghn.org/wiki/index.php/Milestones:List_of_IEEE_Milestones |title=List of IEEE Milestones |work=IEEE Global History Network |publisher=IEEE |access-date=4 August 2011}}</ref> Nagel was awarded the 2019 IEEE Donald O. Pederson Award in Solid-State Circuits for the development of SPICE.<ref>[https://sscs.ieee.org/membership/awards/donald-o-pederson-solid-state-circuits-award/ Donald O. Pederson Solid-State Circuits Award], [[IEEE Solid-State Circuits Society]], June 2018</ref>

== Successors ==
=== Open-source successors ===
No newer versions of Berkeley SPICE have been released after version 3f5 in 1993.<ref>{{cite web |title=The Spice Page |url=http://bwrcs.eecs.berkeley.edu/Classes/IcBook/SPICE/ |website=University of California at Berkeley. |archive-url=https://web.archive.org/web/20231208045915/http://bwrcs.eecs.berkeley.edu/Classes/IcBook/SPICE/ |archive-date=December 8, 2023 |url-status=dead}}</ref> Since then, the open-source or academic continuations of SPICE include: 

* XSPICE,<ref>{{Cite book|doi=10.1109/ISCAS.1992.230083|chapter=Code-level modeling in XSPICE|title=&#91;Proceedings&#93; 1992 IEEE International Symposium on Circuits and Systems|year=1992|last1=Cox|first1=F.L.|last2=Kuhn|first2=W.B.|last3=Murray|first3=J.P.|last4=Tynor|first4=S.D.|volume=2|pages=871–874|isbn=0-7803-0593-0|s2cid=195705106}}</ref> developed at [[Georgia Institute of Technology|Georgia Tech]], which added mixed analog/digital "code models" for behavioral simulation; 
* CIDER<ref>CODECS: A Mixed-Level Circuit and Device Simulator, K. Mayaram, Memorandum No. UCB/ERL M88/71, Berkeley, 1988, http://www.eecs.berkeley.edu/Pubs/TechRpts/1988/ERL-88-71.pdf</ref> (previously CODECS), developed by UC Berkeley and Oregon State University, which added [[semiconductor device modeling|semiconductor device simulation]];
* [[Ngspice]],<ref>[https://fosdem.org/2019/schedule/event/ngspice/ "ngspice, current status and future developments"], H. Vogt, FOSDEM, Brussels 2019</ref><ref>{{cite web|url=https://peertube.f-si.org/videos/watch/62e7ad36-e7fc-4884-971a-9fcedf17d9f2 |title=ngspice - an open source mixed signal circuit simulator |publisher=Free Silicon Foundation (F-Si) | access-date=2019-07-08}}</ref> based on SPICE 3f5;
* WRspice,<ref>{{cite web|url=https://github.com/wrcad/xictools |title=WRspice |publisher=Whiteley Research | access-date=2021-05-07}}</ref> a C++ re-write of the original spice3f5 code.
* [[SPICE OPUS]]

Not a descendant but compatible:
* [[Quite Universal Circuit Simulator|QUCS]], which uses an independently-developed Qucsator backend but understands SPICE input. The QUCS-S variant supports using a SPICE-derived backend.<ref>[https://ra3xdh.github.io/ QUCS-S software]</ref>
* Xyce, independent but compatible work from Sandia National Laboratories. Parallel (MPI) C++ for high performance and large netlists.<ref>[https://xyce.sandia.gov/ Xyce software, Sandia National Laboratories.]</ref>

=== Commercial versions and spinoffs ===
Berkeley SPICE inspired and served as a basis for many other circuit simulation programs, in academia, in industry, and in commercial products. The first commercial version of SPICE is ISPICE,<ref>{{Cite book|doi=10.1109/BIPOL.1990.171136|chapter=SPICE: The third decade|title=Proceedings on Bipolar Circuits and Technology Meeting|year=1990|last1=Vladimirescu|first1=A.|pages=96–101|s2cid=62622975}}</ref> an interactive version on a timeshare service, [[National CSS]]. The most prominent commercial versions of SPICE include HSPICE (originally commercialized by [[Ashawna Hailey|Ashawna and Kim Hailey]] of Meta Software, but now owned by [[Synopsys]]) and [[PSPICE]] (now owned by [[Cadence Design Systems]]). The integrated circuit industry adopted SPICE quickly, and until commercial versions became well developed many IC design houses had proprietary versions of SPICE.<ref>K. S. Kundert, ''The Designer's Guide to SPICE and Spectre'', Kluwer. Academic Publishers, Boston, 1995</ref>

Today a few IC manufacturers, typically the larger companies, have groups continuing to develop SPICE-based circuit simulation programs. Among these are

* ADICE and [[LTspice]] at [[Analog Devices]],
* [[QSPICE]] at [[Qorvo]],
* MCSPICE, followed by Mica at [[Freescale Semiconductor]], now [[NXP Semiconductors]], and
* [[TINA (software)|TINA-TI]]<ref>[http://www.ti.com/tool/tina-ti SPICE-Based Analog Simulation Program - TINA-TI - TI Software Folder] {{webarchive |url=https://web.archive.org/web/20161019062912/http://www.ti.com/tool/tina-ti |date=October 19, 2016 }}</ref> at [[Texas Instruments]].

Both LTspice and TINA-TI come bundled with models from their respective company.<ref name="Kay2012">{{cite book|author=Art Kay|title=Operational Amplifier Noise: Techniques and Tips for Analyzing and Reducing Noise|url=https://books.google.com/books?id=0_PkTgqJD3kC&pg=PA41|year=2012|publisher=Elsevier|isbn=978-0-08-094243-8|page=41}}</ref><ref name="Mancini2012">{{cite book|author=Ron Mancini|title=Op Amps for Everyone|url=https://books.google.com/books?id=0J6GtAlcHUcC&pg=PA162|year=2012|publisher=Newnes|isbn=978-0-12-394406-1|page=162}}</ref>

Other companies maintain internal circuit simulators which are not directly based upon SPICE, among them PowerSpice at [[IBM]], TITAN at [[Infineon Technologies]], Lynx at [[Intel Corporation]], and Pstar at [[NXP Semiconductors]] also.<ref>{{Cite AV media|url=https://nescacademy.nasa.gov/video/7aa4def451454697a6ecdbbe088a6f3b1d|title=PSPICE Circuit Simulation Overview: Part 1|date=August 2012|last=Iannello|first=Chris|type=Video|language=English|time=2:39}}</ref>

== Program features and structure ==
SPICE became popular because it contained the analyses and models needed to design integrated circuits of the time, and was robust enough and fast enough to be practical to use.<ref name="SPICE4">Nagel, L., [http://www.cs.sandia.gov/nacdm/talks/Nagal_Larry_NACDM2004.pdf Is it Time for SPICE4?] {{webarchive |url=https://web.archive.org/web/20060926034314/http://www.cs.sandia.gov/nacdm/talks/Nagal_Larry_NACDM2004.pdf |date=September 26, 2006 }}, 2004 Numerical Aspects of Device and Circuit Modeling Workshop, June 23–25, 2004, Santa Fe, New Mexico. Retrieved on 2007-11-10</ref> Precursors to SPICE often had a single purpose: The BIAS<ref>{{cite journal |author=McCalla and Howard |title=BIAS-3: A program for nonlinear D.C. analysis of bipolar transistor circuits |journal=IEEE Journal of Solid-State Circuits |volume=6 |number=1 |date=February 1971 |pages=14–19 |doi=10.1109/JSSC.1971.1050153 |bibcode=1971IJSSC...6...14M }}</ref> program, for example, did simulation of bipolar transistor circuit operating points; the SLIC<ref>{{cite journal |first1=T.E. |last1=Idleman |first2=F.S. |last2=Jenkins |first3=W.J. |last3=McCalla |first4=D.O. |last4=Pederson |title=SLIC: A simulator for linear integrated circuits| journal=IEEE Journal of Solid-State Circuits |volume=6 |number=4 |date=August 1971 |pages=188–203 |doi=10.1109/JSSC.1971.1050168 |bibcode=1971IJSSC...6..188I }}</ref> program did only small-signal analyses.  SPICE combined operating point solutions, transient analysis, and various small-signal analyses with the circuit elements and device models needed to successfully simulate many circuits.

=== Analyses ===
SPICE2 includes these analyses:
* AC analysis ([[linear]] [[small-signal model|small-signal]] frequency domain analysis)
* DC analysis (nonlinear [[quiescent point]] calculation)
* DC transfer curve analysis (a sequence of nonlinear operating points calculated while sweeping an input voltage or current, or a circuit parameter)
* Noise analysis (a small signal analysis done using an adjoint matrix technique which sums uncorrelated noise currents at a chosen output point)
* [[Transfer function]] analysis (a small-signal input/output gain and impedance calculation)
* Transient analysis (time-domain large-signal solution of nonlinear differential algebraic equations)

Since SPICE is generally used to model circuits with [[nonlinear element]]s, the small signal analyses are necessarily preceded by a [[quiescent point]] calculation at which the circuit is linearized. SPICE2 also contains code for other small-signal analyses: [[sensitivity analysis]], [[Pole–zero plot|pole-zero analysis]], and [[small-signal]] [[distortion]] analysis. Analysis at various temperatures is done by automatically updating semiconductor model parameters for temperature, allowing the circuit to be simulated at temperature extremes.

Other circuit simulators have since added many analyses beyond those in SPICE2 to address changing industry requirements. Parametric sweeps were added to analyze circuit performance with changing manufacturing tolerances or operating conditions. Loop gain and stability calculations were added for analog circuits. [[Harmonic balance]] or time-domain steady state analyses were added for RF and switched-capacitor circuit design. However, a public-domain circuit simulator containing the modern analyses and features needed to become a successor in popularity to SPICE has not yet emerged.<ref name="SPICE4"/>

It is very important to use appropriate analyses with carefully chosen parameters. For example, application of linear analysis to nonlinear circuits should be justified separately. Also, application of transient analysis with default simulation parameters can lead to qualitatively wrong conclusions on circuit dynamics.<ref>{{cite book |first=Giovanni |last=Bianchi |title=2015 7th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT) |arxiv=1506.02484| date = 2015 |chapter= Limitations of PLL simulation: hidden oscillations in SPICE analysis |pages=79–84 |doi=10.1109/ICUMT.2015.7382409 |isbn=978-1-4673-9283-9 |s2cid=7140415 }}</ref>

=== Device models ===
SPICE2 includes many semiconductor device [[transistor models|compact models]]: three levels of [[MOSFET]] model, a combined [[Ebers-Moll model|Ebers–Moll]] and [[Gummel–Poon model|Gummel–Poon bipolar model]], a [[JFET]] model, and a model for a [[diode|junction diode]]. In addition, it had many other elements: resistors, capacitors, inductors (including [[Inductance#Coupled inductors|coupling]]), independent [[voltage source|voltage]] and [[current source]]s, ideal [[transmission line]]s, active components and voltage and current controlled sources.

SPICE3 added more sophisticated MOSFET models, which were needed due to advances in semiconductor technology.
In particular, the [[BSIM]] family of models were added, which were also developed at UC Berkeley.

Commercial and industrial SPICE simulators have added many other device models as technology advanced and earlier models became inadequate. To attempt standardization of these models so that a set of model parameters may be used in different simulators, an industry working group was formed, the [[Compact Model Council]],<ref>{{cite web|url=http://www.geia.org/index.asp?bid=597 |title=CMC - Compact Model Council |publisher=GEIA |url-status=dead |archive-url=https://web.archive.org/web/20110511071827/http://www.geia.org/index.asp?bid=597 |archive-date=May 11, 2011 }}</ref> to choose, maintain and promote the use of standard models.  The standard models today include [http://www-device.eecs.berkeley.edu/bsim/?page=BSIM3 BSIM3], [http://www-device.eecs.berkeley.edu/bsim/?page=BSIM4 BSIM4], [https://web.archive.org/web/20150224064144/http://www-device.eecs.berkeley.edu/bsim/?page=BSIMSOI BSIMSOI], [https://web.archive.org/web/20071017140132/http://pspmodel.asu.edu/ PSP], [http://www.iee.et.tu-dresden.de/iee/eb/hic_new/hic_start.html HICUM], and [https://www.eng.auburn.edu/~niuguof/mextram/index.html MEXTRAM].

Spice can use device models from foundry [[Process design kit|PDKs]].

===Input and output: Netlists, schematic capture and plotting===
SPICE2 takes a text [[netlist]] as input and produces line-printer listings as output, which fits with the computing environment in 1975.  These listings are either columns of numbers corresponding to calculated outputs (typically voltages or currents), or line-printer [[ASCII art|character "plots"]]. SPICE3 retains the netlist for circuit description, but allows analyses to be controlled from a [[command line interpreter|command-line]] interface similar to the [[C shell]]. SPICE3 also added basic [[X Window System|X]] plotting, as [[UNIX]] and engineering [[workstation]]s became common.

Vendors and various free software projects have added [[schematic capture]] [[Frontend and backend|frontends]] to SPICE, allowing a [[schematic diagram]] of the circuit to be drawn and the netlist to be automatically generated and transferred to various SPICE backends. Also, [[graphical user interface]]s were added for selecting the simulations to be done and manipulating the voltage and current output vectors. In addition, very capable graphing utilities have been added to see waveforms and graphs of parametric dependencies. Several free versions of these extended programs are available.

== SPICE usage beyond electronic simulation ==
As SPICE generally solves non-linear differential algebraic equations, it may be applied to simulating beyond the electrical realm.

Most prominent are '''thermal simulations''', as thermal systems may be described by lumped circuit elements mapping onto the electronic SPICE elements (heat capacity → capacitance, thermal conductance/resistance → conductance/resistance, temperature → voltage, heat flow or heat generated → current <ref>{{cite web|url=http://ngspice.sourceforge.net/ngspice-electrothermal-tutorial.html |title=ngspice tutorial on electro-thermal simulation | access-date=2022-05-06}}</ref>). As thermal and electronic systems are closely linked by power dissipation and cooling systems, electro-thermal simulation today is supported by semiconductor device manufacturers offering (transistor) models with both electrical and thermal nodes.<ref>{{cite web|url=https://www.iisb.fraunhofer.de/content/dam/iisb2014/en/Documents/Research-Areas/Energy_Electronics/publications_patents_downloads/Publications/Therm_Modelling_2000_IISB.pdf |title=Thermal Modeling of Power-electronic Systems |author1=M. Maerz |author2=Paul Nance |publisher= Fraunhofer IISB | access-date=2022-05-06}}</ref> So one may obtain electrical power dissipation, resulting in self-heating causing parameter variations, and cooling system efficiency in a single simulation run.

SPICE may very well simulate the electronics part of a motor drive. However it will equally well describe the '''electro-mechanical''' model of the motor. Again this is achieved by mapping mechanical onto the electrical elements (torque → voltage, angular velocity → current, coefficient of viscous friction → resistance, moment of inertia → inductance).<ref>{{cite web|url=https://www.precisionmicrodrives.com/ab-025 |title=AB-025: Using SPICE To Model DC Motors |date=22 September 2021 |publisher=Precision Microdrives| access-date=2022-05-06}}</ref> So again the final model consists of only SPICE compatible lumped circuit elements, but one gains mechanical together with electrical data during simulation.<ref>{{cite journal |author=Pham and Nathan |title=Circuit Modeling and SPICE Simulation of Mixed-Signal Microsystems |journal=Sensors and Materials |volume=10 |number=7 |date=1998 |pages=435–460 |url=https://www.myukk.org/SM2017/sm_pdf/SM345.pdf }}</ref>

'''Electromagnetic modeling''' is accessible to a SPICE simulator via the PEEC (partial element equivalent circuit) method.<ref name="ruehli2017">{{cite book|author1=Albert E. Ruehli|author2=Giulio Antonini|author3=Lijun Jiang|title=Circuit Oriented Electromagnetic Modeling Using the PEEC Techniques|url=https://books.google.com/books?id=v-UGCwAAQBAJ&q=CIRCUIT+ORIENTED+ELECTROMAGNETIC+MODELING+USING+THE+PEEC+TECHNIQUES|year=2017|publisher=Wiley|isbn=978-1-11-843664-6}}</ref> Maxwell's equations have been mapped, RLC, Skin effect, dielectric or magnetic materials and incident or radiated fields have been modelled.

However, as of 2019, SPICE cannot{{elaborate|reason=Obviously with a simple enough model, you can simulate photonics.  If it cannot simulate, then simulate must have a specialize meaning.  What is it?|date=May 2025}} be used to "simulate photonics and electronics together in a '''photonic circuit simulator'''",<ref>{{cite journal |last1=Bogaerts |first1=Wim |last2=Chrostowski |first2=Lukas |title=Silicon Photonics Circuit Design: Methods, Tools and Challenges |journal=[[Laser & Photonics Reviews]] |date=April 2018 |volume=12 |issue=4 |pages=1700237 |doi=10.1002/lpor.201700237 |bibcode=2018LPRv...1200237B |doi-access=free |hdl=1854/LU-8578535 |hdl-access=free}}</ref> and thus it is not yet considered as a test simulator for photonic integrated circuits.

'''Micro-fluidic circuits''' have been modelled with SPICE<ref>{{cite book |first1=H. |last1=Takao |first2=M. |last2=Sugiura |first3=M. |last3=Ishida |first4= K. |last4=Terao |first5=T |last5=Suzuki |first6=F |last6=Shimokawa |first7=F. |last7=Oohira |chapter=Micro fluidic circuit design with |title=2011 IEEE 24th International Conference on Micro Electro Mechanical Systems |chapter-url=https://ieeexplore.ieee.org/document/5734635 |publisher=IEEE |date=2011|pages=1154–1157 |doi=10.1109/MEMSYS.2011.5734635 |isbn=978-1-4244-9632-7 |s2cid=24263237 }}</ref> by creating a pneumatic FET.

SPICE has been applied to model the interface between '''biological and electronic systems''', e.g. as a design tools for synthetic biology and for the virtual prototyping of biosensors and lab-on-chip.<ref>{{cite journal |author=Morgan Madec e.a. |title=Modeling and simulation of biological systems using SPICE language |journal=PLOS ONE|date=2017|volume=12 |issue=8 |pages=e0182385 |doi=10.1371/journal.pone.0182385 |pmid=28787027 |pmc=5546598 |bibcode=2017PLoSO..1282385M |doi-access=free }}</ref>

SPICE has been applied in '''[[operations research]]''' to evaluate perturbed [[supply chain]]s.<ref>{{cite journal |author=Francisco Campuzano-Bolarín e.a. |title=Network simulation method for the evaluation of perturbed supply chains on a finite horizon |url=https://zbmath.org/?q=an:07432780|journal=CEJOR, Cent. Eur. J. Oper. Res|date=2021|volume=29 |issue=3 |pages=823–839|doi=10.1007/s10100-021-00748-3 |s2cid=235523347 }}</ref>

SPICE has been used to model loudspeakers, earphones, and headphones.<ref>{{cite journal
  |title=SPICE simulation of headphones and earphones
  |author=Kahrs, Mark
  |journal=Audio Engineering Society Convention 127
  |year=2009
  |publisher=Audio Engineering Society
  |url=https://aes2.org/publications/elibrary-page/?id=15038 }}</ref>  Such [[electro-mechanical]] transducers often have complex input impedances (see, for example, [[Electrical characteristics of dynamic loudspeakers]]) that present difficulties to the circuits designed to drive them.  Integrated modelling of both components addresses this problem.

==See also==
{{Portal|Electronics|Free and open-source software}}
* [[Comparison of EDA software]]
* [[List of free electronics circuit simulators]]
* [[Input/output Buffer Information Specification]] (IBIS)
* [[SPICE OPUS]]
* [[Transistor model]]

== References ==
{{Reflist}}

== External links ==
{{Commons category|SPICE}}
* [https://embedded.eecs.berkeley.edu/pubs/downloads/spice/index.htm Spice at UC Berkeley]

=== Histories, original papers ===
* [http://www.eecs.berkeley.edu/Pubs/TechRpts/1973/22871.html The original SPICE1 paper]
* [http://www.eecs.berkeley.edu/Pubs/TechRpts/1975/9602.html L. W. Nagel's dissertation (SPICE2)]
* [http://www.eecs.berkeley.edu/Pubs/TechRpts/1989/1216.html Thomas Quarles' dissertation (SPICE3)]
* [http://www.ecircuitcenter.com/SpiceTopics/History.htm A brief history of SPICE]
* [http://embedded.eecs.berkeley.edu/pubs/downloads/spice/index.htm SPICE2 and SPICE3 at UC Berkeley]
* [http://embedded.eecs.berkeley.edu/pubs/downloads/cider/index.htm Cider at UC Berkeley]
* [http://www.eeworldonline.com/spice-how-to-choose-an-analysis/ SPICE: how to choose an analysis]

{{CAD software}}
{{Authority control}}

[[Category:1973 software]]
[[Category:Electronic design automation software]]
[[Category:Free software programmed in C]]
[[Category:Free software programmed in Fortran]]
[[Category:Simulation programming languages]]
[[Category:Electronic circuit simulators]]
[[Category:Free simulation software]]
[[Category:Electronic design automation software for Linux]]
[[Category:Public-domain software with source code]]
[[Category:Software using the BSD license]]