Electronic circuit simulation

The circuit simulation with computers and corresponding circuit simulation programs is today in the development of electronic devices (as well as in training) accepted standard. The operation of simple and complex analog and digital circuits, with the accompanying programs - depending on the size of the simulation model - to simulate appropriately verified and tested, without having to actually implement the desired circuit. However, a prerequisite for a subsequent correct functioning of the circuit simulation of the circuit design (following an appropriate practical realization of a circuit board assembly, or on a chip ), in that the real components are reproduced with sufficient precision in the implementation of the simulation software. As a result, it then saves to a time and cost of the development of electronic circuits and helps the other to better understand the electronics and their problems.

Types of circuit simulations

Depending on the application, a distinction is made between various circuit simulations and their methods:

Analog circuit simulation

The analog simulation circuit, the electronic components (e.g. resistors, capacitors, semiconductors, logical and arithmetic circuits, etc.) are represented as mathematical models. By values ​​for the nodal points (nodes ) of the circuit can be calculated by means of network equations, results in a comprehensive data matrix for the simulated circuit. Basis of the equation system are the Kirchhoff's rules.

The analysis of this data can be displayed during simulation with virtual measuring and display instruments.

In addition to the pure test of functionality, the simulated circuits can be analyzed as the following aspects:

  • TLC analysis (such as output voltage versus input voltage)
  • AC analysis (for example, output voltage as a function of frequency)
  • Transientenanlyse (eg behavior of the circuit with short voltage peaks )
  • Fourier analysis (e.g., frequency spectrum)
  • Sensivitätanalyse ( behavior of the circuit with variation of the component parameters )
  • Monte Carlo analysis ( stochastic process )

Since about 1970, worked at the University of California at Berkeley intensively on the first circuit simulation. In 1972 the first version of SPICE (Simulation Program with Integrated Circuit Emphasis) has been released. The program is written in FORTRAN and runs on mainframes. For industry and universities SPICE has become the standard in circuit simulation. In the following years, SPICE has been constantly developed and manufacturers of parts and components set their own mathematical models of their products. Some software manufacturers bought licenses to the source code of SPICE and developed from their own programs for circuit simulation. As a consequence, appeared in 1980 as the first PSpice simulation program for PCs on the market.

It was followed by other programs such as Multisim Electronics Workbench, MICROCAP, LTspice and many others. From 1985, new versions of SPICE in C were programmed. Many of the programs for circuit simulation can be downloaded as free software ( GPL), shareware or free student version from the internet today. But common to all, that works in the background, a more or less current version of SPICE.

Extensions in this area consist instead of netlists and schematics to also use hardware description languages ​​to model the circuit to be simulated at a higher level of abstraction. Thus an attempt is made with VHDL -AMS to extend the originally intended only for the modeling of discrete digital circuits language VHDL on the analog circuit simulation. Currently (2007) there are already Simulators for VHDL -AMS, which are in direct competition with the products based mostly on SPICE circuit simulators.

Differential equation Verilog
712071
de