Electronics Glossary – A
Distributors of Commercial, Industrial, Medical, Automotive, and Hi-Rel Electronic Components
| Term | Definition |
|---|---|
| “A” Stage | The condition of low molecular weight of a resin polymer during which the resin is readily soluble and fusible. |
| AB | Designation for high voltage butyl cable. |
| ABCD parameters | The set of parameters for a two-port device that relates the input voltage and current to the output voltage and current. The transfer function of a cascaded circuit can be determined from the product of the ABCD parameters for the individual components from input to output. |
| ABP | Designation for butylpolyethylene high voltage cable, 75°C. |
| abrasion resistance | A measure of the ability of a wire or wire covering to resist damage by mechanical means. |
| absolute maximum ratings | Specifications that, if exceeded, could cause permanent damage to the converter. There are not continuous ratings, and proper operation is not implied. |
| absolute temperature scale | The temperature scale whose origin is the temperature at which all molecular motion would cease. The unit is the degree Kelvin (oK), which has the same magnitude as a degree celsius (oC). |
| absorbing clamp | A testing fixture, used to measure radiation from a cable, that uses ferrite rings to absorb radiated emissions; power measurements are made by sensing the resulting rf currents induced in the rings. |
| absorption | (1) The amount of moisture a given substance will assimilate and retain. An important property consideration in the selection of insulating materials. (2) Loss of power in an optical fiber, resulting from conversion of optical power into heat and caused principally by impurities, such as transition metals and hydroxyl ions, and also by exposure to nuclear radiation. |
| absorptive device | A circuit or device that absorbs power, i.e., converts incident electrical energy into heat or some other form of energy, rather than reflecting electrical energy back to the source. |
| absorptive filter | A lossy filter that absorbs and dissipates unwanted frequencies as heat. AMP QuietLine filters are absorptive. |
| AC | Alternating Current. An electrical current that reverses its direction of flow at regular intervals (ac, 60 hertz [cps] means reversing direction of flow each half cycle or 120 times per second). |
| AC filter | A filter circuit that removes unwanted frequencies (harmonics) from a mostly AC current. This would include some EMI filters. |
| AC flux density | Number of flux lines per unit of cross-sectional area generated by an alternating magnetic field; Gauss |
| ACA | Designation for synthetic tapes, felted asbestos wire with glazed cotton or glass braid overall, 1000V, 90°C. |
| accelerated aging | A test in which voltage, temperature, or other test parameters are increased above normal operating values to obtain observable deterioration in a relatively short time. The plotted results give service life within the context of the test. |
| accelerator | A chemical additive which hastens a chemical reaction under specific conditions. Another term is promoter. |
| acceptance angle | The half-angle of the cone within which incident light is totally internally reflected by the fiber core. It is equal to arcsin (NA). |
| acceptor | A material that is intentionally added to a pure semiconductor material to increase the population of free holes in that semiconductor, resulting in a net positive charge. A semiconductor that has had acceptor material added to it is called “p-type.” |
| access method | The method by which networked stations determine when they can transmit data on a shared transmission medium. Also, the software within an SNA processor that controls the flow of information through a network. |
| access provider | Organization providing and maintaining network services for subscribers. |
| access rate | The transmission speed, in bits per second, of the physical access circuit between the end user and the network. |
| access time | The time interval between the instant at which information is: (a) called for from storage and the instant at which delivery is completed, (b) ready for storage and the instant at which storage is completed. |
| accessories | Mechanical devices, such as cable clamps and jackscrews, added to connectors to make up the total connector configuration. |
| accumulator | Device used for temporary data storage in arithmetic or logic operation. Usually stores one quantity and, on receipt of another, forms the sum and temporarily stores the result. |
| ACR | Designation for cable with corona resisting insulation. |
| Action Pin contact | Any of several style contacts manufactured exclusively by AMP, having a split pin to provide gastight retention in a printed circuit board plated thru hole without solder. |
| active device | A component that has gain or operates in a non-linear fashion to change the basic character of an electric signal by, for example, amplification or rectification, or a device comprised of such component, for example a transistor switch. A device whose output is dependent upon an external source of power other than the input signal. |
| active element | Those components of a circuit that have gain or direct current flow. They change the basic character of the applied electrical signal by rectification, amplification, switching, etc. Examples include diodes, transistors, and SCRs. |
| active high | Power switch enable input voltage must exceed the device’s defined threshold voltage for the device to turn on (typically 1.5V). Conversely, enable input voltage must fall below the threshold voltage to turn the device off. |
| active low | Power switch enable input voltage must fall below the device’s defined threshold voltage for the device to turn on (typically 1.5V). Conversely, enable input voltage must exceed the threshold voltage to turn the device off. |
| active network | A circuit that produces gain. |
| active substrate | A substrate in which active elements are formed. Silicon is an active substrate in monolithic integrated circuits. |
| A-D converter | Analog-to-digital converter. Circuitry which accepts a continuously varying voltage or current input and converts it to a digital output. The input may be dc or ac, the output serial or parallel, binary or decimal. |
| ADA | A computer programming language, used by the Department of Defense and named after Lord Byron’s daughter, a friend and collaborator of Charles Babbage who conceived the first operating computer. |
| adapter | A device usually attached to the rear of connectors that provides for the attachment of harnessing components, such as strain-relief clamps, heat-shrinkable boots, and braid. |
| adder | A digital circuit which forms the sum and carry of two or more numbers. |
| address | A specific location where data is stored in a memory; a numerical or alphabetical designation of the storage location of data. |
| address field | That part of an instruction or word containing an address or operand. |
| adhesive | Dual-wall tubing and precoated molded parts whose inner layer melts and flows when heated, fills voids in the areas being covered, and forms a mechanical bond to the substrate. Unlike an encapsulate, an adhesive forms a mechanical bond to the substrate. |
| adhesive liner | Lining that melts and flows inside a sleeve or molded part, filling any voids in between the substrate and the sleeve or molded part. DuraSeal has an adhesive liner. |
| admittance | The ratio of current to voltage, the reciprocal of impedance. The unit of admittance is the siemens (S). Admittance is typically abbreviated as “y” or “Y.” |
| ADSL | A new method of transmitting at speeds up to 7 Mbps in one direction over a single copper telephone line, with up to 640 kbps in the other direction. |
| AFC | Automatic Frequency Control – In frequency modulated (fm) signal processing, a scheme for automatic tuning of circuitry to input signal. Often used to correct for drift in conventionally tuned circuits. |
| AGC | Automatic Gain Control – A feedback system that changes the gain of an amplifier or the attenuation of an attenuator in response to variations in magnitude of the input signal, thereby maintaining the output signal of the system at a constant magnitude. |
| aging | (1) Change in the properties of a material over time and under specific conditions. Generally refers to environmental stimulus such as heat and light. (2)Operating a converter under controlled conditions for a predetermined time in order to screen out failures. Also see Burn-in. |
| A-GPS | Assisted GPS |
| AI | See artificial intelligence. |
| air core inductance | The inductance that would be measured if the core had unity permeability and the flux distribution remained unaltered. (A measure of the inductance of a coil without a core). |
| air gap | A non-magnetic discontinuity in a ferro-magnetic circuit. For example, the space between the poles of a magnet, if filled with brass, wood, or any other non-magnetic material, is nevertheless called an air gap. Air gaps are often introduced into soft ferrite cores to prevent saturation at high DC bias currents or to simply hold a tight inductance tolerance. |
| AL value | The inductance rating of a core in nanoHenries per turn squared (nH/N2) based on a peak flux density of 10 gauss (1 milliTesla) at a frequency of 10 kHz. An AL value of 40 would produce 400µH of inductance for 100 turns and 40mH for 1000 turns. |
| aliphatic hydrocarbons | Saturated hydrocarbons, such as gasoline and propane, whose molecules do not have carbon atoms in a ring structure. |
| alloy | In plastics, a blend of polymers with other polymers or copolymers. |
| alphanumeric | Code structures using letters and numerals, often with added special symbols. |
| Alternating Current | AC – The movement of charge carriers in a medium where the direction in which the carriers move reverses over time, typically with a fixed period, for example 60 Hz 120 VAC household current. |
| altitude immersion seal | A seal able to withstand substantial pressure change (for example, from sea level to 75,000 feet). |
| alumina | Refined form of aluminum oxide, pressed in molds and fired to produce a ceramic insulator useful as a substrate for hybrid integrated circuits. |
| aluminum oxide | A mechanically strong, tightly adherent, and nonporous film which forms on aluminum when air and water vapor are present. This film helps resist corrosive attack, and is a good insulator. |
| AM | Amplitude Modulation – modulation in which the amplitude of a wave is the characteristic subject to variation. |
| ambient temperature | The temperature of still air immediately surrounding a component or circuit. A typical method to measure ambient temperature is to record the temperature that is approximately 1/2 inch from the body of the component or circuit. |
| American Society for Testing and Materials | ASTM – A nonprofit industry wide organization that formulates test methods and material specifications, and publishes standards, testing methods, recommended practices, definitions, and other materials. |
| American Wire Gauge | AWG – System of numerical designations for wire size, based on specified ranges of circular mil area. American Wire Gauge starts with 4/0 (0000) at the largest size, going to 3/0 (000), 2/0 (00), 1/0 (0), 1, 2, and up to 40 and beyond for the smallest sizes. |
| ammeter | Instrument designed to measure current flow in amperes. Available for either alternating or direct current. A millimeter measures current flow in milliamperes, and a microammeter in microamperes. See galvanometer. |
| amnesia | The tendency over time for a heat-shrinkable elastomeric tubing or molded part to fail to recover completely to its specified recovered size. See Shelf Life. |
| amorphous | Having no definite order of crystalline structure. Refers to magnetic materials that are metallurgically non-crystalline in nature. |
| AMP | (1)Brand name long associated with the highest quality interconnection products and systems! (2) Ampere – Practical unit of electrical current; the current flow rate (ie, quantity of electrons passing a point in 1 second). Voltage of 1 volt will send a current of 1 ampere through a resistance of 1 ohm. |
| ampacity | See Current-carrying Capacity. |
| AMP-Duragold | AMP trademark for its gold-over-palladium plating. |
| ampere | Abbreviated A or amp. Practical unit of electrical current; the current flow rate (ie, quantity of electrons passing a point in 1 second). Voltage of 1 volt will send a current of 1 ampere through a resistance of 1 ohm. |
| ampere turns | The product of current (I) flowing in the winding times the number of turns (N). |
| ampere-turns per meter | The MKS unit of magnetizing force, H, as shown by Ampere’s Law. |
| amplifier | A circuit, device, or component which provides an output signal essentially identical to the input signal, but at a higher power or signal level. |
| amplitude | The magnitude of variation in a changing quantity from its zero value. The word requires modification – as with adjectives such as peak, maximum, rms – to designate the specific amplitude in question. |
| Amplitude Modulation | AM – The modification of the magnitude of a higher, constant frequency carrier signal controlled by the amplitude and phase of a lower frequency baseband or audio signal. |
| amplitude permeability | The quotient of the peak value of flux density and peak value of applied field strength at a stated amplitude of either, with no static field present. (µa) |
| AMPS | Advanced Mobile Phone System. The original American standard for analog wireless phone systems, used primarily in North America, Latin America, Australia and parts of Russia and Asia. |
| analog | A signal which is continuously variable and, unlike a digital signal, does not have discrete levels. (A slide rule is analog in function.) |
| analog computer | Computer which represents numerical quantities as electrical and physical variables. Solutions to mathematical problems are accomplished by manipulating these variables. |
| and gate | A logic circuit with two or more input variables. All inputs must be energized – or receive a signal simultaneously – for the output to be energized. |
| anechoic chamber | A testing enclosure in which the walls are formed of specially designed material that absorbs incident energy and prevents it from reflecting. |
| Angstrom | Unit of distance equal to 10-10 (10E-10) meter. Can be used as a measure of light wavelength, or to indicate the thickness of surface films or oxides. The symbol for angstrom is Ã…. |
| angular misalignment | The loss of optical power caused by deviation from optimum alignment of fiber to fiber or fiber to waveguide. |
| anisotropic | A material whose electrical properties vary with different polarization of a traveling wave. |
| anneal | To heat a metal and cool slowly to relieve hardness or brittleness that may have occurred naturally or have been induced by pressure or bending. |
| anode | The positive lead or pole in batteries, plating apparatus, diodes, etc. |
| anodize | Formation of a protective, insulating oxide layer on a metal (eg aluminum) by electrolytic action. Anodized finishes can be natural or any bright decorative color. |
| ANSI | American National Standards Institute Inc. – operates a voluntary certification program. |
| ANSI T1.403 | The performance-monitoring, data-link, and network interface requirements for ESF CSUs as defined by the Exchange Carriers Standards Association. T1.403 specifies automatic performance reports transmitted to the network once per second via the data link. (In an E1 environment, Performance Monitor is the equivalent of T1.403). |
| ANSI T1.413 | The interface standard for DMT ADSL. |
| antenna | A structure that is intended to radiate electromagnetic waves into or collect electromagnetic energy from space. |
| antistatic | Of or pertaining to the ability to either prevent the accumulation of or to enable the dissipation of static charge. |
| anvil | The term most commonly used to identify that part of the crimping die – normally stationary – which positions and supports the terminal during crimping. Sometimes referred to as “nest.” |
| APD | Avalanche photodiode. |
| applicator | Tooling used in semi- automatic or automatic machines to crimp strip-form or tape- mounted contacts, terminals, etc. Standard – Installed in a machine to produce a fixed crimp height for a particular size and type of terminal; most commonly used where tooling and product changes are infrequent.; Miniature Quickchange – Designed for quick and easy interchange with other similar applicators in a given machine. Each applicator will, in many cases, handle similar products and various wire sizes (AWG). |
| arc resistance | The capacity of insulating material to resist the passage of current on its surface when placed between two electrodes. Arc resistance values are given in seconds. Minimum acceptable arc resistance is approximately 115 seconds. Breakdown usually occurs as a conducting path is burned on the surface of the dielectric material. |
| ARINC | Aeronautical Radio, Inc. – a commercial standards group governing connectors, connector sizes, rack and panel configurations, etc, primarily for airborne applications. Connectors which conform to ARINC specifications are sometimes referred to as ARINC connectors. |
| Arithmetic and Logic Unit | ALU – That portion of the digital computer hardware in which arithmetic and logic operations are performed. |
| Artificial Intelligence | AI – The ability of a computer to perform tasks, such as reasoning and learning, that human intelligence is capable of doing. |
| artwork | Topological pattern of an integrated circuit accurately dimensioned for use in maskmaking. Generally a multiple of final mask size, which is usually produced by a step-and-repeat camera process. |
| AS/400 | A midrange IBM computer system. Originally implemented on twinaxial cable, now generally implemented on UTP cable using baluns. |
| ASCII | American Standard Code for Information Interchange. A 7-bit code used to represent 128 unique letters, numbers, and special characters. An eighth bit is used for parity. |
| ASE | Designation for service entrance cable, above ground use. Some constructions are suitable for underground use. Covering is flame retardant, moisture resistant, and abuse resistant. |
| ASIC | application specific integrated circuit |
| ASP | (1) A filled direct burial telephone cable used in areas subject to rodent attack. It consists of a filled cable core, corrugated aluminum shield, corrugated steel tape, flooding compound and polyethylene jacket. (2) Application Service Provider |
| asperities | Microscopic surface elevations due to surface roughness of a material. |
| a-spots | Abbreviation for asperity spot, the point of physical contact between an asperity on one surface and another surface. |
| assembler | A program that converts the assembly language of a computer program into the machine language of the computer. |
| assembly language | Grouped alphabet characters, called mnemonics, that replace the numeric instructions of machine language. A computer language that has one-to-one correspondence with an assembly program. |
| assymetrical transmission | Transmission which sends data at different rates in each direction, faster downstream than upstream. |
| ASTM | American Society for Testing and Materials – a non-profit industry-wide organization that formulates test methods and material specifications, and publishes standards, testing methods, recommended practices, definitions, and other materials. |
| asynchronous | Not all elements of a device or system operating at the same time, nor in a predetermined sequence. |
| asynchronous transmission | Transmission in which time intervals between transmitted bits may be of unequal length. Transmission is controlled by start and stop bits which frame each character. |
| ATE | Automatic test equipment. |
| ATM | Asynchronous Transfer Mode – communication protocol for broadband transmission of voice, data and video that uses fixed-length packets or cells to switch traffic over the local- and wide-area network. |
| attenuation | Power loss resulting in weaker signals in an electrical system as the signals travel along wires. Occurs naturally during wave travel through lines, waveguides, space, or a medium such as water. May be produced intentionally by placing an attenuator in a circuit. Amount of attenuation is generally expressed in decibels or decibels per unit of length. In cables, generally expressed in dB per unit length, usually 100 feet. In optical fibers, it is measured in decibels per kilometer at a specified wavelength. Attenuation measurements are common for voltage, current, and power. For a power ratio, one dB = 10Log10(P1/P2). For a current ratio, one dB = 20Log10(I1/I2). For a voltage ratio, one dB = 10Log10(V1/V2). A dB is equal to 20Log(I1/I2) for current and 20Log(V1/V2) for voltage ratios. |
| attenuation-limited operation | The condition in a fiber-optic link when operation is limited by the power of the received signal (rather than by bandwidth or by distortion). |
| attenuator | A two port circuit or device that reduces the amplitude of an input signal by a desired amount typically expressed in decibels (dB). Attenuators may be comprised of fixed resistors. PIN diodes or FET’s, or combinations of these. |
| atto | A prefix that indicates a factor of 10-18, abbreviated as “a.” |
| audio amplifier | A circuit with one or more stages designed to amplify the audio frequency range (about 20 to 20,000 Hz). |
| autoclaves | Closed vessels used for vacuum pressure impregnating, high pressure curing, bonding, sealing, compressing, testing, etc. |
| Automatic Frequency Control | AFC – In frequency modulated (fm) signal processing, a scheme for automatic tuning of circuitry to input signal. Often used to correct for drift in conventionally tuned B129circuits. |
| Automatic Gain Control | AGC – A feedback system that changes the gain of an amplifier or the attenuation of an attenuator in response to variations in magnitude of the input signal, thereby maintaining the output signal of the system at a constant magnitude. |
| avalanche photodiode | A photodiode that exhibits internal amplification of photocurrent through avalanche multiplication of carriers in the junction region. |
| avionics | Application of electronics to aviation and space exploration. |
| AVL | Automotive Vehicle Location |
| AWG | American Wire Gauge – gauging system used to size wire (recognized method in the United States). The higher the gauge number, the smaller the conductor size. Every increase of 3 wire gauges is a 50% reduction in cross sectional area of the wire. |