Electronic component

An electronic component is a basic electronic element and may be available in a discrete form (a discrete device or discrete component) having two or more electrical terminals (or leads). These are intended to be connected together, usually by soldering to a printed circuit board, in order to create an electronic circuit (a discrete circuit) with a particular function (for example an amplifier, radio receiver, or oscillator). Basic electronic components may be packaged discretely, as arrays or networks of like components, or integrated inside of packages such as semiconductor integrated circuits, hybrid integrated circuits, or thick film devices. The following list of electronic components focuses on the discrete version of these components, treating such packages as components in their own right.

Contents

Classification

A component may be classified as passive or active. The strict physics definition treats passive components as ones that cannot supply energy themselves, whereas a battery would be seen as an active component since it truly acts as a source of energy.

However electronic engineers performing circuit analysis use a more restrictive definition of passivity. When we are only concerned with the energy due to signals it is convenient to ignore the so-called DC circuit and pretend that the power supplying components such as transistors or integrated circuits is absent (as if each such component had its own battery built in) although it may in reality be supplied by the DC circuit which we are ignoring. Then the analysis only concerns the so-called AC circuit, an abstraction which ignores the DC voltages and currents (and the power associated with them) present in the real-life circuit. This fiction, for instance, allows us to view an oscillator as "producing energy" even though in reality the oscillator consumes even more energy from a power supply, obtained through the DC circuit which we have chosen to ignore. Under that restriction we define the terms as used in circuit analysis as follows:

Passive components can be further divided into lossless and lossy components:

Most passive components with more than two terminals can be described in terms of two-port parameters satisfying the principle of reciprocity, although there are some rare exceptions[2]. In contrast, active components (which have more than two terminals) generally lack that property.

Note that these distinctions only apply to components listed below which would be modeled as elements within circuit analysis. Practical items which act as transducers or have other connections to the outside world such as switches, cannot be subject to this form of classification since they defy the view of the electronic circuit as a closed system.

Components

Terminals and connectors

Devices to make electrical connection

Cable assemblies

Cables with connectors or terminals at their ends

Switches

Components that can pass current ("closed") or break the flow of current ("open")

Resistors

Pass current in proportion to voltage (Ohm's law).

Protection devices

Passive components that protect circuits from excessive currents or voltages

Capacitors

Components that store and release electrical charge. Used for filtering power supply lines, for tuning resonant circuits, and for blocking DC voltages while passing AC signals, among numerous other uses.

Magnetic (inductive) devices

Electrical components that use magnetism

Networks

Components that use more than one type of passive component

Piezoelectric devices, crystals, resonators

Passive components that use piezoelectric effect

Power sources

Sources of electrical power

Transducers, sensors, detectors

  1. Transducers generate physical effects when driven by an electrical signal, or vice-versa.
  2. Sensors (detectors) are transducers that react to environmental conditions by changing their electrical properties or generating an electrical signal.
  3. The Transducers listed here are single electronic components (as opposed to complete assemblies), and are passive (see Semiconductors and Tubes for active ones). Only the most common ones are listed here.

Semiconductors

Diodes

Conduct electricity easily in one direction, among more specific behaviors.

Transistors

Active components used for amplification.

Integrated circuits

Optoelectronic devices

Display technologies

Current:

Obsolete:

Vacuum tubes (Valves)

Based on current conduction through a vacuum (see Vacuum tube)

Amplifying tubes

Optical detectors or emitters

Discharge devices

Obsolete:

Antennas

Antennas transmit or receive radio waves

Assemblies, modules

Multiple electronic components assembled in a device that is in itself used as a component

Prototyping aids

Mechanical accessories

Other

Obsolete:

Standard symbols

Main article: Electronic symbol

On a circuit diagram, electronic devices are represented by conventional symbols. Reference designators are applied to the symbols to identify the component.

See also

References

  1. ^ For instance, a computer could be contained inside a black box with two external terminals. It might do various calculations and signal its results by varying its resistance, but always consuming power as a resistance does. Nevertheless it would be classified as an active component since it relies on a source of power to operate.
  2. ^ Nonreciprocal passive devices include the gyrator (although as a truly passive component this exists more in theoretical terms, and is usually implemented using an active circuit) and the circulator used at microwave and optical frequencies