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Glossary

 



 

 

Glossary

0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

 

A single-wire (plus ground) communications protocol.

A 1-Wire interface master controller.

10-Gigabit Ethernet

3G

Third-generation mobile telephone protocols that support higher data rates, for non-voice communications such as multimedia and Internet access.

Third Generation Partnership Project, a collaboration of cell phone technology standards bodies. www.3gpp.org/.

4G

4th Generation mobile telephony standard with a potential speed of up to 1 gigabit per second for data transfer.

5G

Upcoming 5th Generation mobile telephony standard that can potentially transfer data at up to 20 gigabit per second.

IEEE standard that specifies medium-access and physical-layer specifications for 1Mbps and 2Mbps wireless connectivity between fixed, portable, and moving stations within a local area.

The IEEE standard that governs the deployment of 5GHz OFDM systems. It specifies the implementation of the physical layer for wireless UNII b.

IEEE 802.11ac is a wireless networking standard in the 802.11 family (which is marketed under the brand name Wi-Fi), on the 5 GHz band. The specification has multi-station throughput of at least 1 gigabit per second and single-link throughput of at least

An international IEEE standard for WLAN networks, operating at 2.4GHz and providing a maximum data transfer rate of 11Mbps.

A proposed standard that describes a wireless networking method for a WLAN that operates in the 2.4GHz radio band (ISM: Industrial Scientific Medical frequency band). It transfers data at up to 54Mbps.

An IEEE 802.11 Wi-Fi standard that increases transmission speeds to 600 Mbps and works in both the 2.4 GHz and 5 GHz frequency bands (see dual-band router).

A-weighting is a standard weighting curve applied to audio measurements, designed to reflect the response of the human ear.

Analog to digital. Specifically: A/D converter, a circuit that converts analog signals into a stream of digital data.

A sensor or transducer for measuring acceleration.

Advanced Configuration and Power Interface: An industry-standard specification (co-developed by Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba) for operating-system-directed power management for laptop, desktop, and server computers. A replacemen

Adjacent (alternate)-channel power ratio

ACR

Accumulated current register

ADM

Add/Drop Multiplexer: A synchronous transmission network (SDH or Sonet) can carry multiple channels. An Add/Drop Multiplexer is a device that adds (inserts) or drops (removes) lower-data-rate channel traffic from the higher-rate aggregated channel.

Adaptive Differential Pulse Code Modulation: A compression technique that encodes only the difference between sequential samples.

ADS

Analog design system

Asymmetric Digital Subscriber Line: A method for moving data over regular phone lines. An ADSL circuit carries much more data than a modem can encode on a regular phone connection. ADSL rides on the regular phone wires coming into the subscriber's premise

A qualification test sequence for integrated circuits developed by the AIAG automotive organization.

AFE

Analog Front End: The analog portion of a circuit which precedes A/D conversion.

AGC

Automatic Gain Control: A circuit that modulates an amplifier's gain, in response to the relative strength of the input signal, in order to maintain the output power.

Ah

Ampere-hour(s): A measure of battery capacity. A 4Ah battery could, for instance, deliver 1A for 4 hours, 1/2A for 8 hours, etc.

A method for testing ESD-protection structures in which the ESD generator is discharged through an air gap between the generator and the device under test (DUT).

The Antenna Interface Standards Group (AISG) creates open specifications for antenna-line control and monitoring for 3G systems.

In A/D conversion, the Nyquist principle states that the sampling rate must be at least twice the maximum bandwidth of the analog signal. If the sampling rate is insufficient, then higher-frequency components are "undersampled" and appear shifted to lower

An electromechanical device that converts mechanical power into AC electrical power.

AM

Amplitude Modulation: A modulation method in which the carrier amplitude changes with the input signal amplitude.

Temperature of the air surrounding a component.

Temperature sensor used to measure the temperature of the air that surrounds a component (the ambient temperature).

Active-matrix liquid-crystal display

Amp

1. Ampere

The amount of current a conductor can carry without exceeding its specified temperature, in amperes.

Ampere(s), the unit of electrical current. Current is defined as the amount of charge that flows past a give point, per unit of time.

A measure of charge (or current flow over time).

An electrical circuit that produces an output that is a replica of the input. The output may be scaled or have increased drive, or it may provide isolation (so changes in output conditions do not affect the input or other outputs). It may perform other tr

Amplifier circuit types are divided into "classes" which describe whether the amplifier operates in a linear or switching mode, and any techniques used to restore linearity of output.

Advanced Mobile Phone System: An analog only, 1G standard that operates in the 800MHz to 900MHz frequency band. It is still widely used in the United States.

AMR

Automatic Meter Reading: A system installed to read a utility meter remotely.

A system in which an electrical value (usually voltage or current, but sometimes frequency, phase, etc.) represents something in the physical world. The electrical signal can then be processed, transmitted, amplified, and finally, transformed back into a

An analog switch (sometimes just called a "switch") is a switching device capable of switching or routing analog signals (meaning signals that can have any level within a specified legal range), based on the level of a digital control signal. Commonly imp

Temperature sensor with a continuous analog voltage or current output that is related, usually linearly, to the measured temperature.

AND

Combining two signals so that the output is on if both signals are present. This can be accomplished by an AND logic gate (two inputs, one output which is high if both inputs are).

American National Standards Institute

An anti-aliasing filter is used before A/D conversion. It is a lowpass filter that removes signal components above the Nyquist frequency, thereby eliminating their sampled replicas (aliases) in the baseband.

APC

Automatic Power Control: Feature in laser driver that uses feedback from the laser to adjust the drive, to keep the laser's output constant.

APD

Avalanche Photo Diode: A photodiode designed to take advantage of avalanche multiplication of photocurrent to provide gain. As the reverse-bias voltage approaches the break-down voltage, hole-electron pairs created by absorbed photons acquire sufficient e

API

Application program interface: A software layer that allows a system to be programmed via a defined set of commands.

APM

Advanced Power Management: Power management standard for computers that provides five power states: Ready, Stand-by, Suspended, Hibernation, Off.

ATM (-based) passive optical network

Advanced Product Quality Planning. System developed by the AIAG automotive organization to communicate common product quality planning and control plan guidelines for suppliers to the automotive industry.

American Standard Codes for Information Interchange

Application-specific integrated circuit

ATE

Automatic test equipment; automated test equipment

ATM

Asynchronous transfer mode

A feature in EIA-232 interface devices which puts the IC into a low-power shutdown mode when no signal is present on the EIA-232 bus.

A feature in EIA-232 interface devices which puts the IC into a low-power shutdown mode when no signal is present on the bus or the transmitter inputs.

An autotransformer is a transformer that uses a common winding for both the primary and secondary windings. Essentially an inductor with a center-tap, an autotransformer is often used in power-supply boost-converter applications to achieve a higher output

AWG

1. Arbitrary waveform generator

B

1. Bel: Measurement of a signal's power compared to a reference; also, measurement of sound pressure. See the more commonly used term, "decibel," or, "dB."

Step-up, switching-regulator power supply with a backup battery switchover.

1. Bandwidth (BW) is a range of frequencies, or information, that a circuit can handle or the range of frequencies that a signal contains or occupies.

A base station (or basestation) is a wireless transceiver at a fixed location (e.g. atop a telephone pole) which is part of a wireless communications network, e.g. the cell phone network. Typically, the base station connects to any cell phones in its area

The electrical signal from a sensor when no measured variable is present. Often referred to the output at no-load condition.

A feature of microprocessor supervisory circuits and some power supplies to switch between a main power source and a battery.

A feature in microprocessor supervisory circuits which disconnects a backup battery from any down-stream circuitry until VCC is applied the first time. This keeps a backup battery from discharging until the first time a board is plugged in and used, and t

A feature or device that measures the accumulated energy added to and removed from a battery, allowing accurate estimates of battery charge level.

A feature that monitors the voltage on a battery and indicates when the battery is low. It is usually implemented using a comparator to compare the battery voltage to a specified level. May also include functions such as charging, remaining capacity estim

A circuit that switches between the higher of a main supply and a backup battery.

BCD

Binary-coded decimal: Representation of a number in which each decimal digit (0-9) is encoded in binary, with four bits per decimal digit.

BER

Bit Error Rate: A measure of the number of erroneous bits which can be expected in a specified number of bits in a serial stream.

Bit Error Rate (BER) Tester: A piece of test equipment which determines the bit error rate for a device under test (DUT).

BGA

Ball grid array: A packaging technology.

The device accommodates signals traveling either direction though a single channel.

An input which accommodates signals both above and below ground.

A Bipolar Junction Transistor, or BJT, is a solid-state device in which the current flow between two terminals (the collector and the emitter) is controlled by the amount of current that flows through a third terminal (the base).

Built-in self-test.

A technique which uses the general-purpose ports of a microcontroller to emulate a serial interface standard (I2C, SPI, etc).

The number of erroneous bits divided by the total number of bits transmitted, received, or processed over some stipulated period.

BLE

BLE transmits less data over shorter distances using much less power than Bluetooth

Controls the display segment blink rate.

A technology that allows voice and data connections between a wide range of mobile and stationary devices through short-range digital two-way radio. For instance, it specifies how mobile phones, Wireless Information Devices (WIDs), computers and PDAs inte

Bus low-voltage differential signal

BOC

Bit-oriented code

A boost converter (step-up converter) is a DC-to-DC powerconverter that steps up voltage (while stepping down current) from its input (supply) to its output (load).

A power supply that steps an input voltage up (boosts it) to a higher, regulated voltage.

Often refers to using the output of a step-up converter to drive the main power FET switch, providing more gate drive than the input can supply alone. Also refers to using a switched capacitor to boost the voltage of a node.

Broadband passive optical network

Binary phase-shift keying

BRD

Band-rate divisor

Break-Before-Make: A switch that is configured to break (open) the first set of contacts before engaging (closing) the new contacts. This prevents the momentary connection of the old and new signal paths.

BRI

Bit-rate interface

A battery intended to provide power to system memory while the main battery is replaced.

Used in audio applications, the load (a speaker in this case) is connected between two audio amplifier outputs (it "bridges" the two output terminals).

Although the terms "brightness" and "luminance" are often used interchangeably, they are different. Luminance is the light intensity; brightness is how it is perceived by the human eye.

A transmission medium with enough bandwidth to carry multiple voice, video, or data channels simultaneously.

A condition where the voltage supplied to the system falls below the specified operating range, but above 0V.

BSC

BSC (Basic Spacing between Centers) is a term that appears on IC package drawings in reference to dimensions between pins.

Best-straight-line fit

BT

Butterworth (filter)

BTS

Base Transceiver Station: The stationary component of a cellphone system includes transmit-receive units and one or more antennae. The combined systems (often including multiple co-located systems and ganged directional antennae) is called a cell-site, a

A "buck" or "step-down" switch-mode voltage regulator is one in which the output voltage is lower than its input voltage.

A switch-mode voltage regulator in which output voltage can be above or below the input voltage.

Burst Dimming is a method of controlling the brightness of cold cathode fluorescent lamps (CCFL) by turning the lamps on and off at a rate faster than the human eye can detect. The on/off rate is nominally 100Hz to 300Hz. The higher the ratio of on-time t

1) A temporary high-speed data-transfer mode that can transfer data at significantly higher rates than would normally be achieved with nonburst technology.

Bus

Data path that connects to a number of devices. A typical example is the bus a computer's circuit board or backplane. Memory, processor, and I/O devices may all share the bus to send data from one to another. A bus acts as a shared highway and is in lieu

Bandwidth, Large Signal

Bandwidth, Small Signal

C

1. Capacitance, capacitor

C/N

Carrier-to-noise

CA

Common anode

A wire is a single conductor while cable is a group of two or more conductors.

CAD

Computer-aided design

CAN

Controller Area Network. The CAN protocol is an international standard defined by ISO 11898.

A phenomenon where a signal on one line/trace is capacitively coupled to an adjacent line/trace.

A capacitor is a passive electronic component that consists of two conductive plates separated by an insulating dielectric. A voltage applied to the plates develops an electric field across the dielectric and causes the plates to accumulate a charge. When

32-bit version of the PC card (formerly PCMCIA) standard

CAS

Column-Address-Strobe: The signal that tells the DRAM to accept the given address as a column-address; used with RAS and a row-address to select a bit within the DRAM

Category 3: Refers to Ethernet cabling that satisfies the criteria for the EIA/TIA-568 standard's Category 3, which allows data transfers up to 10Mbps.

Category 5: Refers to Ethernet cabling that satisfies the criteria for the EIA/TIA-568 standard's Category 5, which allows data transfers up to 100Mbps.

CBR

Constant bit rate

Constant Current/Constant Voltage battery charger

Constant current/constant voltage

CCD

Charge Coupled Device: One of the two main types of image sensors used in digital cameras. When a picture is taken, the CCD is struck by light coming through the camera's lens. Each of the thousands or millions of tiny pixels that make up the CCD convert

Cold Cathode Fluorescent Lighting: Often used as a backlight for LCD displays.

Cold Cathode Fluorescent Tube: Often used as a backlight for LCD displays.

CCK

Complementary code keying

CCM

Continuous-conduction mode; crossconnect module

CDC

Clock distribution circuit

CDD

Clock Distribution Device or Clock Distribution Driver

Code Division Multiple Access: A digital cellular technology that uses spread-spectrum techniques. Unlike GSM and other competing systems that use TDMA, CDMA does not assign a specific frequency to each user. Instead, every channel uses the full available

CDR

Clock/data recovery. Clock/data recovery is a function or circuit that extracts a clock signal from an incoming data stream.

Chip enable control

CH

Chebyshev (filter)

Channel-to-channel skew. A signal on one channel has a different phase than the same signal on another channel (delayed/skewed). This is measured in picoseconds, max.

Channel Associated Signaling (CAS): Some communications protocols include "signaling" functions along with data. Channel Associated Signaling protocols include signaling in the data channel (as opposed to a dedicated signaling channel).

Channels

A parameter pertinent to analog switches. As an analog switch turns on and off, a small amount of charge can be capacitively coupled (injected) from the digital control line to the analog signal path.

A power supply which uses capacitors to store and transfer energy to the output, often stepping the voltage up or down. Charge is transferred from one capacitor to another under control of regulator and switching circuitry. 

Method the battery charger uses to determine when to terminate the charging cycle.

CHAnnelized T1 and E1 And Universal HDLC controller

Integrated circuit: A semiconductor device that combines multiple transistors and other components and interconnects on a single piece of semiconductor material.

A feature in microprocessor supervisory circuits which prevents the writing of erroneous data when power falls outside of spec. When the main power-supply voltage is below the minimum safe-operating limit, the feature disconnects the chip-enable signal pa

A choke is an inductor used to block higher-frequency alternating current (AC) in an electrical circuit, while passing lower-frequency or direct current (DC).

A chopper circuit is used to refer to numerous types of electronic switching devices and circuits used in power control and signal applications. 

The color portion portion of a composite video signal. Forms a complete picture once combined with the luminance component.

CID

Consecutive identical digit(s)

CIM

Cable integrity monitor

Complex instruction set computer (CISC): Computer hardware designed to support complex instructions, as opposed to RISC (reduced instruction set computer) architecture.

The simplest type of amplifier, class A amplifiers are those in which the output transistors conduct (i.e. do not fully turn off) irrespective of the output signal waveform. This type of amplifier is typically associated with high linearity but low effici

Class AB amplifiers combine Class A and Class B to achieve an amplifier with more efficiency than Class A but with lower distortion than class B.

Class B amplifiers are those in which the output transistors only conduct during half (180 degrees) of the signal waveform. To amplify the entire signal two transistors are used, one conducting for positive output signals and the other conducting for nega

A class C amplifier is a form of switching amplifier in which the transistors are on for less than a half cycle (less than 180 degrees) -- often, much less. For instance, the transistor may be on only during the top 10% of the signal excursion, delivering

Class D amplifiers are those that output a switching waveform, at a frequency far higher than the highest audio signal that needs to be reproduced. The low-pass filtered, average value of this waveform corresponds to the actual required audio waveform.

Class G amplifiers are similar to class AB amplifiers except they use two or more supply voltages. When operating at low signal levels, the amplifier uses a lower supply voltage. As the signal level increases, the amplifier automatically picks the appropr

Class H amplifiers modulate the supply voltage to the amplifier output devices so that it is never higher than necessary to support the signal swing. This reduces dissipation across the output devices connected to that supply and allows the amplifier to o

A feature that eliminates "clicks" and "pops" — unwanted transient noise signals during power-up, shutdown, connection, etc.

The process of extracting and reconstructing clock and data information from a single-wire/channel, serial data stream.

A periodic waveform (especially a clock) is expected to cross certain thresholds at precisely timed moments. Variations from this ideal are called jitter.

Reducing the frequency or duty-cycling the clock of an integrated circuit usually for the purpose of reducing heat generation.

cm

Centimeter: 1/100 of a meter, 0.39 inches.

CMF

Current-mode feedback

CMI

Code matrix insertion

CML

Current-mode logic

Complementary metal-oxide semiconductor technology in which p- and n-channel MOS transistors are used in tandem.

Common Mode Rejection Ratio: The ability of a differential amplifier to not pass (reject) the portion of the signal common to both the + and - inputs.

CO

Coarse offset

Short for compressor/decompressor, a codec is any technology for compressing and decompressing data. Codecs can be implemented in software, hardware, or a combination of both.

COG

Chip-on-glass

Describes the sampling of a periodic signal, where an integer number of its cycles fits into a predefined sampling window.

An electromagnetic coil is an electrical conductor such as a wire in the shape of a coil, spiral or helix.

Correction loop capacitor

A modulated carrier, added to a television signal, to carry the color components.

Common-mode signals are identical signal components on both the + and - inputs of a differential amplifier or instrumentation amplifier. A common example is in a balanced pair, where a noise voltage is induced in both conductors. Another example is where

Comparator propagation delay. This is the lag between the input crossing the comparator threshold, and the output changing states.

Signal processing technique which uses both compression and expansion to improve dynamic range and signal-to-noise ratio.

A comparator is a device that accepts two analog inputs, compares the inputs, and produces a binary output that is a function of which input is higher. If the non-inverting (+) input is greater than the inverting (-) input, then the output goes high. If t

Central Office Line: telephone line

CompoNet is a four-wire, industrial, bus with a master-slave architecture. It is used at the lower network levels to transmit bit or word information, such as for use in sensors and actuators. Up to 256 slaves are supported on a bus. Data rates of 93.75kb

Attaching electronic components to a printed circuit board

When a mechanical switch or relay closes, the switch elements will often bounce, even if only briefly, before making final contact. This is of consequence if downstream elements are sensitive to the switching transients. A contact debouncing circuit is of

An ESD test method where the ESD generator makes direct contact with the device under test (DUT).

In a general sense, a controller can be thought of as something or someone that interfaces between two systems and manages communications between them.

A line which is in the same plane as another line. Any two intersecting lines must lie in the same plane, and therefore be coplanar.

Coulomb (abbreviated C) is the standard measure of electrical charge.

CP

Comparable part

Ceramic pin grid array, an IC packaging technology.

CRC

Cyclic Redundancy Check: A check value calculated from the data, to catch most transmission errors. A decoder calculates the CRC for the received data and compares it to the CRC that the encoder calculated, which is appended to the data. A mismatch indica

Command register and interface logic

In an output stage (or similar amplifying stage which uses one device to pull the signal up and another to pull the signal down), the region in which the high-side device is turning on and the low-side device is turning off, or vice versa.

A crowbar circuit is a power supply protection circuit that rapidly short-circuits ("crowbars") the supply line if the voltage and/or current exceeds defined limits. In practice, the resulting short blows a fuse or triggers other protection, effectively s

The art and science of breaking encryption or any form of cryptography.

CS

Chip select

CSP

Chip Scale Package: An IC packaging technology in which solder balls take the place of pins, making the smallest package available. When heated, the solder balls alloy to matching pads on the circuit board.

Retry timeout capacitor

Startup timer capacitor

Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms.

An alternative op amp topology usually used in high-speed amplifiers. It is sensitive to feedback impedance, and cannot be used as an integrator.

A DC-DC switching regulator which regulates its output voltage by varying the peak inductor current on a cycle-by-cycle basis to output a regulated voltage despite variations in load-current and input-voltage.

An amplifier that measures current by measuring the voltage drop across a resistor placed in the current path. The current sense amp outputs either a voltage or a current that is proportional to the current through the measured path.

Digital-to-analog converter (DAC): A data converter, or DAC, that receives digital data (a stream of numbers) and outputs a voltage or current proportional to the value of the digital data.

A method of propagating signals along a bus in which the devices are connected in series and the signal passed from one device to the next. The daisy chain scheme permits assignment of device priorities based on the electrical position of the device on th

System which acquires data, generally by digitizing analog channels and storing the data in digital form. These systems can be standalone or married to a computer and can acquire multiple channels of data.

A/D or D/A converter: An electronic circuit that converts analog signals to digital, or vice-versa.

dB

Decibels: A method for specifying the ratio of two signals.

dBm

A unit that defines a signal level by comparing it to a reference level. The reference level of 0dBm is defined as 1mW. The signal level in dBm is 10 times the log of the signal's power over that of the 0dBm reference.

DBS

Direct Broadcast Satellite: A system which broadcasts directly from satellite to the subscriber (end user). Prominent examples in the US are DirecTV and Dish network.

DC

Direct current

A DC motor is any of a class of rotary electrical machines that converts direct current electrical energy into mechanical energy.

A power inverter, or inverter, is an electronic device or circuitry that changes direct current (DC) to alternating current (AC). The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or ci

A DC-to-DC converter is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another

A DC-DC converter (switch-mode power supply) in which the power switch (usually a power MOSFET) is external to the IC.

DCE

Data communications equipment; interchangeable with DTE

DCM

Discontinuous-conduction mode

DCR

Direct conversion receiver

DCS

Digital Cellular System: Any cellular phone system that uses digital (e.g. TDMA, GSM, CDMA).

DDI

Digital data input

DDJ

Data-dependent jitter

Double Data Rate Synchronous DRAM: A clock is used to read data from a DRAM. DDR memory reads data on both the rising and falling edge of the clock, achieving a faster data rate. Often used in notebook computers because it also consumes less power.

Data direction register D

DDS

DDS (direct digital synthesis) is a method for digitally generating analog waveforms, such as sine waves (modulated or not) or arbitrary waveforms.

Electrical contacts in mechanical pushbutton switches often make and break contact several times when the button is first pushed. A debouncing circuit removes the resulting ripple signal, and provides a clean transition at its output.

Digital European cordless telephone

An analog-to-digital converter (ADC) architecture consisting of a 1-bit ADC and filtering circuitry which over-samples the input signal and performs noise-shaping to achieve a high-resolution digital output. The architecture is relatively inexpensive comp

Design For Testability (or Design for Test, or DFT) refers to design techniques that make products easier to test. Examples include the addition of test points, parametric measurement devices, self-test diagnotics, test modes, and scan design.

Design tools are objects, media, or computer programs, which can be used to design electronic systems

Reproducible jitter within a given system, under controlled conditions. Also known as bounded jitter.

DFE

Decision feedback equalization

Design Failure Mode and Effects Analysis (DFMEA) is a method for evaluating a design for robustness against potential failures.

DG

Differential gain

Uses a Kelvin connection at a remote location to sense the output voltage and better control the voltage at that point.

Most electrical signals are single-ended, comprised of a single wire and ground. Differential signals use two wires which are the inverse of each other -- when one swings positive, the other swings negative in equal magnitude. The receiving circuit looks

Digital logarithmic potentiometer.

Digital potentiometer: A solid-state device that emulates a mechanical potentiometer, it is usually controlled via a simple interface.

A Digital Signal Processor, or DSP, is a special-purpose digital circuit that acts on digitized signals, such as audio. DSP circuits can replace traditional analog functions, such as filtering and more complex functions that are difficult to accomplish in

DIO

Data input/output

A two-terminal device that rectifies signals (passes current in only one direction). Most commonly, a semiconductor consisting of a P-N junction, but dioides can also be realized using vacuum tube, point-contact, metal-semiconductor junction (Schottky), a

DIP

DIP (Dual Inline Package) is an integrated circuit package with two rows of pins.

An elementary electronic device constructed as a single unit.

An electronic visual display, informally a screen, is a display device for presentation of images, text, or video transmitted electronically, without producing a permanent record.

In systems that handle electrical signals, distortion is a generally unwanted change in the signal.

A common technique to improve digitizing when quantization noise (quantization error/noise) can no longer be treated as random. A small amount of random noise is added to the analog input signal. This added noise causes the digital output to randomly togg

DIU

Digital interface unit

In radio systems, diversity is a method of improving the reliability and capacity by using multiple communication channels to carry each signal.

DLC

Double-layer capacitor

DMA

Direct Memory Access: A scheme which reads or writes data directly to memory, bypassing the processor and the processor bus.

DML

Data Manipulation Language (or Data Management Language): A language that allows data to be manipulated in a database. In SQL, commands such as DELETE and INSERT are DML commands.

DMM

Digital Multimeter: Measuring instrument or VOM (e.g. voltage, resistance, current) with a digital display.

DMR

Digital microwave radio

DMT

Discrete multitone data transmission

DNL

Differential Nonlinearity: A specification that appears in data-converter datasheets. In an ideal D/A converter, incrementing the digital code by 1 changes the output voltage by an amount that does not vary across the device's permitted range. Similarly,

Data Over Cable Service Interface Specification: A standard for delivering data over cable TV systems, typically for subscriber Internet access services.

A device which provides frequency conversion to a lower frequency, e.g. in digital broadcast satellite applications.

DP

Differential phase; also decimal place

Discrete packaging

DPD

Digital phase detector

Double-pole/double-throw

DPH

Data pointer high

DPL

Data pointer low

DPM

Digital panel meter

DPS

Data pointer select

Double-pole/single-throw

Digitally adjusted pulse-width modulation

Differential quadrature phase-shift keying

One of the three terminals that comprise a FET. A voltage on the gate controls the current flow between the source and drain.

Dynamic RAM: Random-Access Memory that uses a continuous clock. Unlike SRAM, when DRAM is no longer clocked, its data is lost.

DRC

Design-rule checking

In electronics, a driver is an electrical circuit or other electronic component used to control another circuit or component, such as a high-power transistor, liquid crystal display (LCD), and numerous others.

Drypack is a method for packing integrated circuits in a moisture-free environment. The device is baked and immediately sealed in a vacuum-sealed bag.

DSL

A mechanism for providing high-speed digital communications (e.g. Internet access) over a standard phone line.

Digital Subscriber Line Access Multiplexer: a device which takes a number of ADSL subscriber lines and concentrates these to a single ATM line.

DSP

Digital signal processing (DSP) refers to various techniques for improving the accuracy and reliability of digital communications. 

Digital-sensor signal processor

Direct-Sequence Spread Spectrum: A transmission technology used in WLAN (wireless LAN) transmissions where a data signal at the sending station is combined with a higher data-rate bit sequence, or chipping code, that divides the user data according to a s

DTB

Digital terrestrial broadcasting

DTE

Data terminal equipment; interchangeable with DCE

Dual Tone Multiple Frequency (DTMF) is a signaling method developed by Bell Labs for sending telephone dialing information over the same analog, voice-quality phones lines that carry voice.

Two modes of operation. Examples: In power circuits, the IC can deliver either a fixed 5V or an adjustable 1.3V to 16V source. In cellular phones, the IC operates in FM or CDMA mode, AMPS or TDMA mode, etc.

Switching regulator that employs dual-phase technique to reduce output noise and boost output current capability.

Dual-band refers to the capability of GSM network infrastructure and handsets to operate across two frequency bands.

A Dual-Modulus Prescaler (DMP) is an important circuit block used in frequency synthesizers to divide the high-frequency signal from the voltage controlled oscillator (VCO) to a low-frequency signal by a predetermined divide ratio, either (N+1) or N, whic

DVB

Digital Video Broadcast is a name for digital TV.

DVM

Digital voltmeter

Dense Wave Division Multiplexing: The technology by which the frequencies of light carried on a single optical fiber are subdivided into discrete wavelengths, allowing for the greater transmission of data.

DXC

Digital cross-connect

The range, in dB, between the noise floor of a device and its defined maximum output level.

E1

Wide-area, digital transmission scheme, used predominantly in Europe, that carries data at a rate of 2.048Mbps. E1 lines can be leased for private use from common carriers.

E2

A line that carries four multiplexed E1 signals with a data rate of 8.448Mbps.

E3

Wide-area, digital transmission scheme used predominantly in Europe that carries data at a rate of 34.368Mbps. E3 lines can be leased for private use from common carriers.

EAM

Electro-Absorption Modulators: Chip-level modulation devices often integrated into hybrid transponder devices, alongside lasers.

ECB

Electrically controlled birefringence

ECL

Emitter-coupled logic

The simplest form of microprocessor supervisory circuit, it monitors the power supply for the microprocessor and provides only a power-on reset function.

Erbium-doped fiber-optical amplifier

Enhanced Data Rates for GSM Evolution: An enhanced modulation technique designed to increase network capacity and data rates in GSM networks. EDGE should provide data rates up to 384Kbps.

Electrically erasable programmable read-only memory

EFT

Electrical fast transient

EIA

Electronic Industries Alliance: Among other things, the EIA sponsors electrical and electronic standards.

Electronic Industries Association/Joint Electron Device Engineering Council

Materials studied and used mainly for their electrical properties. The electric response of materials largely stems from the dynamics of electrons, and their interplay with atoms and molecules.

A system in which the computer (generally a microcontroller or microprocessor) is included as an integral part of the system.

EMC

Electromagnetic Compatibility: The ability of electronic equipment to be a "good electromagnetic neighbor": It neither causes, nor is susceptible to, electromagnetic interference (within the limits of applicable standards).

EMI

Electromagnetic Interference: Unwanted noise from electromagnetic radiation.

An electrical enclosure is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment.

Behavior of the device at the limit of temperature or voltage.

Encoder/Decoder

Energy harvesting (also known as power harvesting or energy scavenging) is the process in which energy is captured from a system's environment and converted into usable electric power. Energy harvesting allows electronics to operate where there's no conve

Electrical energy measurement basics.

Energy storage is the capture of energy produced at one time for use at a later time.

Effective Number of Bits: An indication of the quality of an analog-to-digital converter (ADC). The measurement is related to the test frequency and the signal-to-noise ratio.

Ethernet (-based) passive optical network

Erasable programmable read-only memory

ERC

Extinction ratio control

ESD

Electrostatic Discharge: Release of stored static electricity. Most commonly: The potentially damaging discharge of many thousands of volts that occurs when an electronic device is touched by a charged body.

Devices added to input and output pins on an IC to protect the internal circuitry from the damaging effect of electrostatic discharge.

ESF

Extended Superframe: A DS1 framing format in which 24 DS0 times lots, plus a coded framing bit are organized into a frame which is repeated 24 times to form a superframe.

ESL

Effective/Equivalent Series Inductance is the parasitic inductance in a capacitor or resistor.

ESP

Extended stack pointer

ESR

Effective Series Resistance (or Equivalent Series Resistance or ESR) is the resistive component of a capacitor's equivalent circuit.

A family of network protocols based on asynchronous frames. The Ethernet framing structure provides a flexible payload container with basic addressing and error detection mechanisms.

EV

Electric Vehicle

Evaluation Kit (EV Kit, Development Kit): A printed circuit board with an integrated circuit and support components to produce a working circuit for evaluation and development. Most Evaluation Kits are fully assembled and tested.

EVM

Error Vector Magnitude: A measure of the difference between the (ideal) waveform and the measured waveform. The difference is called the error vector, usually referred to with regard to M-ary I/Q modulation schemes like QPSK, and shown on an I/Q "constell

EVSE is an abbreviation for Electric Vehicle Service Equipment, referring to a charging station.

Evaluation System: Evaluation kits that also include an interface board for connecting to a personal computer and Windows-based EVKit software.

Offered in some packages to improve thermal dissipation or lower the impedance of the ground connection. Normally not electrically isolated, it typically needs to be connected to a ground or power plane, depending on the device.

F

1. Farad(s): Unit of capacitance.

fA

Femtoampere(s): 10 to the -15 Ampere; a millionth a nanoampere.

A technique used in RS-485 interface transceivers which forces the output to a predefined state in the event of a line short or open circuit.

An integrated circuit that varies the speed and airflow of a cooling fan using a variable voltage in response to temperature or system commands.

An integrated circuit that varies the speed and airflow of a cooling fan using a pulse-width-modulated (PWM) voltage in response to temperature or system commands.

A function that ignores a fault for a predetermined period. This is done to eliminate nuisance fault indication.

Will tolerate excessive voltage during a fault condition.

FB

Feedback

FCD

Fan count divisor

FCR

Fan conversion rate

FDD

Frequency-division duplex

Fiber Distributed Data Interface: A standard for transmitting data on optical fiber cables at a rate of around 100,000,000 bits-per-second (10 times as fast as 10 Base-T Ethernet; about twice as fast as T-3).

FDL

Facility data link: Embedded communications channel in ESF DS1 framing. Used to convey both bit-oriented and message-oriented signals.

FDM

A method for carrying multiple channels of information on one channel by dividing the available bandwidth among the channels.

FE

Functional equivalent (in component cross-reference data); also field engineer; also framing error

FEC

Forward Error Correction: A technique for detecting and correcting errors from imperfect transmission by adding a small number of extra bits. FEC allows optical transmission over longer distances by correcting errors that can happen as the signal-to-noise

A femto base station (also called an Access Point Base Station, femtocell, femtobasestation or femto basestation) is an in-home base station. Like a standard base station, it connects cell phone voice and data to the cell phone network, but it serves a sm

FET

Field-Effect Transistor: A transistor in which the voltage on one terminal (the gate) creates a field that allows or disallows conduction between the other two terminals (the source and drain).

FFT

A Fourier transform (FT) converts a signal from the time domain (signal strength as a function of time) to the frequency domain (signal strength as a function of frequency). It shows the signal's spectral content, divided into discrete bins (frequency ban

FG

Fan gain

Frequency Hopping Spread Spectrum: A transmission technology in which the data signal is modulated by a narrowband carrier signal which changes frequency ("hops") over a wide band of frequencies. The hopping seems random but is prescribed by an algorithm

A highly-reliable, gigabit interconnect technology that allows concurrent communications among workstations, mainframes, servers, data storage systems, and other peripherals using SCSI and IP protocols. It provides interconnect systems for multiple topolo

First-In First Out: A type of memory that stores data serially, where the first bit read is the first bit that was stored.

Electronic filters are circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both.

Apple Computer trademarked name for the IEEE 1394 serial interface standard: A high-speed interface between computers and peripherals such as external disk drives, cameras, and camcorders. Also referred to by Sony trademarked name, "I-Link."

FIT

Failures in time

An analog-to-digital converter that uses a series of comparators with different threshold voltages to convert an analog signal to a digital output.

Flash memory is an electronic (solid-state) non-volatilecomputer storage medium that can be electrically erased and reprogrammed.

A signal line is said to be "floating" if it is not connected to any voltage supply, ground, or ground-referenced signal source.

FM

Frequency Modulation: A modulation method in which the carrier frequency changes with the input signal amplitude.

FOC

Fields oriented control

A circuit which reduces the current limit once the device enters current-limited operation. Commonly seen on RS-422/RS-485 drivers and some power circuits.

Measurement technique in which a voltage (or current) is forced at a remote point in a circuit; then the resulting current (or voltage) is measured (sensed).

A power-supply switching circuit that transfers energy to the transformer secondary when the switching transistor is on.

FOX

Fast-on oscillator

Full-power bandwidth

A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturing – hence "field-programmable".

A high-speed, packet-switched data communications service similar to X.25. Frame relay is a leading contender for LAN-to-LAN interconnect services, and is well suited to the burst-intensive demands of LAN environments.

A device used to align/synchronize to an embedded framing pattern in a serial bit stream. Once synchronized and data fields are properly aligned, overhead bits for alarms, performance monitoring, embedded signaling, etc. may be extracted and processed.

The frequency range and resolution on the frequency axis of a spectrum graph depends on the sampling rate and the size of the data record (the number of acquisition points). The number of frequency points or lines or bands in the power spectrum is NRECORD

In radio systems, Frequency Diversity spreads a signal across multiple channels by transmitting multiple versions of the signal on different frequencies.

A frequency synthesizer is an electronic circuit that uses an oscillator to generate a preprogrammed set of stable frequencies with minimal phase noise. Primary applications include wireless/RF devices such as radios, set top boxes, and GPS.

FS

Full scale; frame sync

FSC

Fan-speed control

FSK

Frequency Shift Keying: A method of transmitting digital data by shifting the frequency of a carrier signal to represent binary 1s and 0s.

FSO

Full-span output

Full-span output temperature coefficient

FSR

Full-scale range

FTC

Fan tachometer count

Fan tachometer count limit

Fiber-to-the-business

Fiber-to-the-home: A method for broadband data (voice, Internet, multimedia, etc.) delivery to the home via optical fiber.

FTTN is "Fiber-to-the-node."

A channel providing simultaneous transmission in both directions.

An electrical safety device that operates to provide overcurrent protection of an electrical circuit.

G

Gram(s)

Gallium arsenide: A semiconductor material used for optoelectronic products such as LEDs, and for high-speed electronic devices.

A Gallium Arsenide (GaAs) Metal-Semiconductor Field-Effect-Transistor (MESFET) is a transistor built with gallium arsenide semiconductor material. The conducting channel is built using a metal-semiconductor (Schottky) junction.

Gallium arsenide field-effect transistor

Gallium Arsenide Phosphide (or, Gallium Arsenic Phosphide): A semiconductor material used for optoelectronics, including LEDs and photodiodes.

The amount of amplification accomplished by an amplifier circuit. For instance, a gain of 2 would mean the output is scaled to twice the amplitude of the input.

The gain error of a data converter indicates how well the slope of an actual transfer function matches the slope of the ideal transfer function.

Gallium arsenide (GaAs) is a compound of the elements gallium and arsenic. It is a III-Vdirect bandgap semiconductor with a Zinc blende crystal structure.

Gallium nitride (GaN) is a material that can be used in the production of semiconductor power devices as well as RF components and light emitting diodes (LEDs).

Galvanic isolation is a design technique that separates electrical circuits to eliminate stray currents. Signals can pass between galvanically isolated circuits, but stray currents, such as differences in ground potential or currents induced by AC power,

The application of a function that transforms brightness or luminance values. Gamma functions are usually nonlinear but monotonic and designed to affect the highlights (whitest values), midtones (grayscale), and shadows (dark areas) separately.

The controlling terminal of a FET. A voltage on the gate controls the current flow between the source and drain.

GbE

Gigabit Ethernet

Gigabit Interface Converter: A removable transceiver module permitting Fibre-Channel and Gigabit-Ethernet physical-layer transport.

GBW

Gain bandwidth

An electromechanical device that converts mechanical power into electrical power.

Gaussian frequency-shift keying: A type of FSK modulation which uses a Gaussian filter to shape the pulses before they are modulated. This reduces the spectral bandwidth and out-of-band spectrum, to meet adjacent-channel power rejection requirements.

GHz

Gigahertz

1 billion bits-per-second.

General term used to describe an undesirable, momentary pulse or unexpected input or output.

A term used in microprocessor supervisory circuit datasheets to describe the maximum magnitude and duration of a negative-going VCC supply-voltage pulse without causing the reset output to assert.

The Russian Global Navigation Satellite System

Gaussian minimum shift keying (GMSK) is a form of frequency shift keying (FSK) used in GSM systems. The tone frequencies are separated by exactly half the bit rate. It has high spectral efficiency.

Experiments, breakthroughs, and research benefiting our industry from any and all government agencies

General Purpose Interface Bus: A standard bus for controlling electronic instruments with a computer. Also called IEEE-488 bus because it is defined by ANSI/IEEE Standards 488-1978, and 488.2-1987.

General Purpose I/O: A flexible parallel interface that allows a variety of custom connections.

Gigabit passive optical network

General Packet Radio Service: A radio technology for GSM networks that adds packet-switching protocols and shorter set-up time for ISP connections; it offers the possibility to charge by amount of data sent rather than connect time.

GPS

Global Positioning System: A satellite- based navigation system in which two or more signals, received from satellites, are used to determine the receiver's position on the globe.

GSM

Global System for Mobile Communications: A land, mobile, pan-European, digital, cellular radio-communications system.

GSM network operating in the 900MHz band, as used by BT Cellnet and Vodafone in the UK, and by more than one hundred countries around the world.

GUI

Graphical user interface

H

Henry(ries): The unit of inductance.

A circuit diagram which resembles the letter "H." The load is the horizontal line, connected between two pairs of intersecting lines. It is very common in DC motor-drive applications where switches are used in the "vertical" branches of the "H" to control

Data transmission over a circuit capable of transmitting in either direction, but not simultaneously.

An ADC architecture which uses a bank of comparators first to digitize the upper half bits, then uses a digital-to-analog converter (DAC) to subtract that voltage from the input, and then digitizes what remains of the input signal to get the lower half bi

Switching an on-going call to a different channel or cell in a wireless cellular network. Also known as "handoff."

The presence of frequencies in the output of a device that are not present in the input signal, and are multiples of components of the input signal. Clipping is a common cause but other nonlinearities can also introduce harmonics.

Highway Addressable Remote Transducer (HART) communication is a commonly used mode of transmission for digital signals that are superimposed on the analog signal of a 4–20mA current loop.

Highly accelerated stress test; highly accelerated steam and temperature.

High-Brightness LEDs are any of a new generation of LEDs bright enough for illumination applications such as automotive interior, exterior, and display; room and architectural illumination; task and general lighting; projection display; display backlights

HBT

Heterojunction bipolar transistor

HD

Harmonic distortion

High Level Data Link Control: An ITU-TSS link layer protocol standard for point-to-point and multi-point communications.

High bit-rate Digital Subscriber Line: The oldest of the DSL technologies, it continues to be used by telephone companies deploying T1 lines at 1.5Mbps and requires two twisted pairs.

High-definition television: an all-digital system for transmitting a TV signal with far greater resolution than the analog standards (PAL, NTSC, and SECAM). A high-definition television set can display several resolutions, (up to two million pixels versus

Mechanical device that is thermally-connected to a heat-producing electronic component, designed to conduct heat away from the device. Most heat sinks are aluminum and employ fins to increase surface area and encourage the transfer of heat to the ambient

High-electron-mobility transistor

HF

High frequency

High gain, low linearity

Hi-Z (or High-Z or high impedance) refers to an output signal state in which the signal is not being driven. The signal is left open, so that another output pin (e.g. elsewhere on a bus) can drive the signal or the signal level can be determined by a pass

Power electronics is the application of solid-state electronics to the control and conversion of electric power.

High voltage is defined by the DOE Electrical Safety Guidelines as over 600 volts. Generally considered to be a wire or cable with an operating voltageof over 600 volts.

An element connected between the supply and the load. High-side current sensing applications measure current by looking at the voltage drop across a resistor placed between the supply and the load.

Trademarked name for Home Radio Frequency, a networking technology which uses antennae and transmitters to provide wireless home networking via transmitted radio signals.

HomePlug (Powerline) is an industry-standard method for transmitting data via the power lines. It can transmit audio, video, control signals, etc. HomePlug is a trademark of the HomePlug Powerline Alliance; Powerline is the generic term for the method. 

A power supply line controller which allows circuit boards or other devices to be removed and replaced while the system remains powered up. Hotswap devices typically protect against overvoltage, undervoltage, and inrush current that can cause faults, erro

HR

High reliability

High-Speed Downlink Packet Access (HSDPA) is a 3G radio interface standard in the HSPA family for wireless and cellular handsets or datacards that increase the datarate and improve the traffic handling of existing UMTS standards.

High-Speed Packet Access (HSPA) is a collection of radio interface standards for wireless and cellular handsets or datacards that increase the datarate and improve the traffic handling of existing UMTS standards.

High-Speed Serial Interface: A short-distance communications standard for data rates from 2Mbps to 52Mbps.

High-Speed Uplink Packet Access (HSUPA) is a 3G radio interface standard in the HSPA family for wireless and cellular handsets or datacards that increase the datarate and improve the traffic handling of existing UMTS standards.

Hyper Text Markup Language: Coding language used to create web pages.

HTS

High-temperature semiconductor

Hyper Text Transport/transfer Protocol

An ESD test method where the ESD generator consists of a 100pF capacitor and a 1.5kohm series resistor.

Heating, Ventilation, and Air Conditioning: Industry term for the systems and technology responsible for the heating, ventilation, and air conditioning in buildings. HVAC systems regulate comfort (temperature and humidity), energy efficiency, and air qual

Hz

Hertz: A measure of frequency. An older term is cycles per second, or cps.

I/O

Input/output

I/Q

1. I/Q modulation is a method for combining two channels of information into one signal so that they can be separated at a later stage. Two quadrature carriers, 90 degrees out of phase, are modulated, then combined.

I2C

I²C (pronounced "I-squared-C" and typeset as I²C but often typed as I2C) is short for "inter-IC bus." I²C is a two-wire, low-speed, serial data connection IC bus used to run signals between integrated circuits, generally on the same board. SMBus™ is elect

Inter-IC Sound (I²S) is an electrical bus interface standard used for connecting digital audio devices. The I²S bus separates clock and data signals, resulting in a very low-jitter connection. The bus consists of three lines: a clock line, a word-select l

IBO

Input Back-Off: In a power amplifier, a measure of how far you must reduce the input power in order to receive the desired output linearity and power. Stated differently, the ratio between the input power that delivers maximum power to the input power tha

IC

1. Integrated circuit: A semiconductor device that combines multiple transistors and other components and interconnects on a single piece of semiconductor material.

ICA

Integrated circuit accumulator

ICR

Internal calibration register

A constant adjustment factor used to correct for discrepancies between an ideal PN junction equation and a measured device.

A method for improving the efficiency of switching regulators by skipping pulses when the circuit is lightly loaded.

IEC

IEC stands for the International Electrotechnical Commission: An "organization that prepares and publishes international standards for all electrical, electronic and related technologies."

IEC 60601 is a series of technical standards for the safety and essential performance of medical electrical equipment

From www.ieee.org: "The IEEE (Eye-triple-E) is a non-profit, technical professional association of more than 360,000 individual members in approximately 175 countries. The full name is the Institute of Electrical and Electronics Engineers, Inc., although

International Electronic Research Corp

IF

Intermediate Frequency: Radio communications systems modulate a carrier frequency with a baseband signal in order to achieve radio transmission. In many cases, the carrier is not modulated directly. Instead, a lower IF signal is modulated and processed. A

IFM

ISDN file manager

IFT

Intermediate-frequency transform

An insulated-gate bipolar transistor (IGBT) is a three-terminal power semiconductor device primarily used as an electronic switch which, as it was developed, came to combine high efficiency and fast switching.

Third Order Input Intercept Point: The point at which the power in the third-order product and the fundamental tone intersect, when the amplifier is assumed to be linear. IIP3 is a very useful parameter to predict low-level intermodulation effects.

IMA

Inverse Multiplexing over ATM, an MGX card module that supports T3 or E3 inverse multiplexing on up to eight T1 or E1 lines.

Receivers typically convert RF signals to a lower Intermediate Frequency (IF) for demodulation. In addition to the IF, a second signal, called the "image frequency" is often generated and filtered out.

The measure of a receiver's ability to reject signals at its image frequency. It is normally expressed as the ratio, in dB, of the receiver's sensitivity at the desired frequency versus the sensitivity at the image frequency.

IMD

Intermodulation Distortion (IMD): When two signals mix in non-linear circuits or devices, new frequency components are created that are not in the original signal. The resulting signal error is called intermodulation distortion, or IMD.

Impedance, represented by the symbol Z, is a measure of the opposition to electrical flow. It is measured in ohms.

Intel Mobile Voltage Positioning: A technology in which the processor voltage (VCC) is dynamically adjusted, based on the processor activity, to reduce processor power. It allows higher processor clock speed at a given power consumption; or lower consumpt

The very rapid change in voltage across an inductor when current flow is interrupted. Snubber diodes are often used to channel this energy in relays, and other inductive loads. Kickback can be a problem (causing EMI and component failure); or it can be us

Wireless power transfer that utilizes electromagnetic induction and requires close contact between the inductive coil of the charger and the coil in the portable device.

An inductor, also called a coil, choke or reactor, is a passive two-terminalelectrical component that stores energy in a magnetic field when electric current flows through it. 

The Industrial Internet is the integration and linking of big data, analytical tools and wireless networks with physical and industrial equipment, or otherwise applying meta-level networking functions, to distributed systems.

InfiniBand architecture is an industry standard, channel-based, switched-fabric, interconnect architecture for servers. InfiniBand architecture changes the way servers are built, deployed, and managed.

Indium gallium arsenide

An Ingress Protection (IP) rating indicates how well an enclosure is protected from penetration by contaminants such as dust or fluids (such as water). IP ratings are defined in the IEC standard 60529.

INL

Integral nonlinearity

Common-mode voltage range (CMVR) or Input Voltage Range (IVR): For signal processing devices with differential inputs, such as an op amp, CMVR is the range of common mode signal for which the amplifier's operation remains linear.

A momentary input current surge, measured during the initial turn-on of the power supply. This current reduces to a lower steady-state current once the input capacitors charge. Hotswap controllers or other forms of protection are often used to limit inrus

Internal Reference. An on-chip voltage reference.

A measure of a data converter's ability to adhere to an ideal slope in its transfer function. It can be specified using end-point or best-straight-line fit. Each of these approaches can yield very different numbers for the same data converter.

An Integrated Heat Spreader (IHS) is the surface used to make contact between a heatsink or other thermal solution and a CPU or GPU processor.

Intellectual Property: Creations of the intellect such as trade knowledge, technical information, and literary or artistic work, including patents, copyrights, and trademarks.

Electronic devices are connected in order to move information from one device to another.

To organize the data sectors on a computer hard disk, so the read/write heads can access information faster.

A process whereby signals mix together in a circuit and nonlinearities in the circuit create undesired output frequencies that are not present at the input.

The Internet of Things (IoT) is the network of physical devices, vehicles, home appliances and other items embedded with electronics, software, sensors, actuators, and connectivity which enables these things to connect and exchange data

Standard method for data transfer used on the Internet. Also known as IP or TCP/IP.

A power inverter, or inverter, is an electronic device or circuitry that changes direct current (DC) to alternating current (AC).The input voltage, output voltage and frequency, and overall power handling depend on the design of the specific device or cir

A switch-mode voltage regulator in which output voltage is negative with respect to its input voltage.

IO-Link is a 24-volt, three-wire, half-duplex, point-to-point sensor and actuator communication interface. Remote configuration, diagnostics, event triggering and process data readout are made possible from a PLC via a three layer protocol stack. IO-Link

IP

In electronic design a semiconductor intellectual property core, IP core, or IP block is a reusable unit of logic, cell, or integrated circuit (commonly called a "chip") layout design that is the intellectual property of one party.

IP3

Third-order intercept point.

IR

Infrared: Light that has a frequency below the visible light spectrum, used for remote controls, line-of-sight wireless data, and night vision applications, among others.

Infrared Data Association: A group of device manufacturers that developed a standard for transmitting data via infrared light waves.

IRE

Institute of Radio Engineers; IREs are units of measurement dividing the area from the bottom of sync to peak white level into 140 equal units. 140 IRE = 1VP-P

IRO

Input-referred offset

IRS

Interface register set

Interface register set address

Interface register set data

IS

IN SEL (control bit)

ISA

Industry-standard architecture

ISI

Inter-Symbol Interference: A form of interference that occurs when echoes of a radio-signal interfere with the original signal. ISI can reduce the effective data rate of wireless LAN transceivers.

ISM

Industrial, Scientific and Medical: Radio frequency bands made available for use by communication equipment without license, within certain maximum emitted power limits. Equipment which uses the ISM band must tolerate interference from other such equipmen

ISO

International Standards Organization

ISP

Internet Service Provider: Company that offers connection to the Internet.

ITU

International Telecommunication Union: An international organization under the UN that is concerned with telecommunications.

Jitter attentuator limit trip.

Just a Bunch of Disks: An array of hard disks without a controller.

Joint Electron Device Engineering Council

A JFET, or junction field-effect transistor, or JUGFET, is a FET in which the gate is created by reverse-biased junction (as opposed to the MOSFET which creates a junction via a field generated by conductive gate, separated from the gate region by a thin

Just-in-time tester.

The slight movement of a transmission signal in time or phase that can introduce errors and loss of synchronization. More jitter will be encountered with longer cables, cables with higher attenuation, and signals at higher data rates. Also, called phase j

Joule (abbreviated J): A measurement of energy or work. In mechanical systems, it's the a force of one newton, moving an object a distance of one meter.

Joint Photography Experts Group; more commonly, files that are compressed using the JPEG standard.

The use of a PN junction on a silicon die for determining die temperature.

JVM

Java virtual machine.

k

1. Kilo: Metric unit representing 1000. E.g.: 1kHz is a 1 kilohertz (1000 Hertz). Note that the k is always lowercase.

Kanal+ support allows a VCR to record audio and video signals captured by both the set top box (STB) and the television, without changing SCART connections on the back of the TV, STB, and VCR.

kb

Kilobit(s)

The area on or near a CPU or GPU processor that the circuit board layout design can not use, due to thermal management components, cooling, and mounting constraints.

kg

Kilogram(s)

kHz

Kilohertz

km

Kilometer(s)

kVM

Keyboard Video Mouse: Defacto standard for the three cables used on a typical cpr: One for the keyboard; one for the monitor (video); one for the mouse. Also: A KVM switch is a switch box used to connect one KVM to multiple computers.

kW

Kilowatt (or kilowatts): 1000 watts.

kWh

Kilowatt hour(s)

The group of radio frequencies extending from 390MHz to 1550MHz. The GPS carrier frequencies (1227.6MHz and 1575.42MHz) are in the L-band.

LAN

Local Area Network: A computer network, usually within one building, that connects computers, file and mail servers, storage, peripherals, and other devices in a way that permits data interchange and sharing of resources. Ethernet and WiFi (802.11) are co

A laser diode, (LD), injection laser diode (ILD), or diode laser is a semiconductordevice similar to a light-emitting diode in which the laser beam is created at the diode's junction.

An IC that supplies modulated current to a laser diode in response to an input serial-data stream.

LCC

1. Leadless Ceramic Chip Carrier or Leadless Chip Carrier: An IC package, usually ceramic, that has no leads (pins). It instead uses metal pads at its outer edge to make contact with the printed circuit board.

LCD

Liquid-crystal display

LDO

Low Drop Out: A linear voltage regulator that will operate even when the input voltage barely exceeds the desired output voltage.

Leakage inductance in a transformer is an inductive component that results from the imperfect magnetic linking of one winding to another.

LED

Light-Emitting Diode: A semiconductor device that emits light (usually visible or infrared) when forward-biased.

A device which translates a logic signal from one type to another, for example, ECL to TTL.

Linear Feedback Shift Register:

Low gain, high linearity

LiDAR is a detection system that works on the principle of radar, but uses light from a laser. It is a surveying method that measures distance to a target by illuminating the target with pulsed laser light and measuring the reflected pulses with a sensor. Differences in laser return times and wavelengths can then be used to make digital 3-D representations of the target.

A light-emitting diode (LED) is a two-lead semiconductorlight source. It is a p–n junction diode that emits light when activated.

LIN

Local Interconnect Network (LIN): Defined by the LIN-BUS consortium, a LIN is a low data-rate, single-wire communications system, used in automotive and heavy vehicle applications.

The ability of a power-supply voltage regulator to maintain its output voltage despite variations in its input voltage.

1. Having the property that the output is proportional to the input. E.g.:  VOUT = k*VIN where k is a constant.

Uses a linear-pass element (BJT or FET) to control/regulate the charging voltage/current.

A voltage regulator that is placed between a supply and the load and provides a constant voltage by varying its effective resistance. 

Lithium batteries for low-power, high-reliability, long-life applications such as non-volatile memory and timekeeping (typically in coin-shaped cells) use a variety of lithium-based chemistries (as differentiated from lithium-ion). 

Lithium and lithium-ion: A number of battery chemistries are based on the element lithium, a highly-reactive metallic element. Lithium-based batteries are common in two applications: Power for portable equipment such as cell phones, laptops, and MP3 playe

LL

Local loopback

Lm

Lumen(s)

Lumen(s) per watt

Local Multipoint Distribution Service: A broadband radio service, located in the 28GHz and 31GHz bands, designed to provide two-way transmission of voice, high-speed data and video (wireless cable TV). In the U.S., FCC rules prohibit incumbent local excha

LNA

Low noise amplifier. Typical use: The first stage of a satellite receiver.

LO

Local oscillator

Load regulation refers to circuitry that compensates for changes in load. Most commonly: Circuits that keep voltage constant as load varies.

The temperature measured on the die of the temperature-measuring integrated circuit.

An element or function of an integrated circuit that measures its own die temperature.

LOL

Loss of lock

A network that spans distances larger than a local area network (LAN). Because electrical and optical transmissions fade over distance, long-haul networks are difficult and expensive to implement.

LTE (Long Term Evolution) is a high-speed mobile communications cellular standard developed by the 3rd Generation Partnership Project (3GPP). LTE is an evolution of GSM/UMTS standards.

LOP

Loss of power

LOS

Loss of signal

Low battery detector

Low line output

Low voltage is defined as 50 volts (V) or less.

An element connected between the load and ground. Low-side current sensing applications measure current by looking at the voltage drop across a resistor placed between the load and ground.

LSB

Least-significant bit. In a binary number, the LSB is the least weighted bit in the number. Typically, binary numbers are written with the MSB in the left-most position; the LSB is the furthest-right bit.

LSI

Large-scale integration (LSI).

LTE

Long-Term Evolution (LTE) is a standard for high-speed wireless communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA technologies. It birdges the gap between 3G and 4G.

1. The emitted light, projected per unit area, measured in cd/m2(candela per square meter). Often incorrectly equated with "brightness".

LVC

Lowest voltage clamp

Low Voltage Differential Signaling

Low Voltage Emitter Coupled Logic

Low Voltage Positive Emitter Coupled Logic

LVS

Layout versus schematic

Low Voltage Transistor-Transistor Logic

M2M

Machine-to-machine or machine-to-mobile communications, via wireless technologies such as cell phone network technologies, WLAN, Bluetooth, and RFID (radio frequency identification). Applications include automatic meter reading, fleet management, vending,

mA

Milliampere, or milliamp: 1/1000 of an Ampere. Ampere is the basic unit for measuring electrical current.

Media Access Control Address (maca, MAC): A hardware address that uniquely identifies each node of a network, as in IEEE-802 (Ethernet) networks. The MAC layer interfaces directly with the network medium.

An electromagnet is a type of magnet in which the magnetic fieldis produced by an electric current. 

Manchester encoding is a form of binary phase-shift keying (BPSK) that has gained wide acceptance as a modulation scheme for low-cost radio-frequency (RF) transmission of digital data. Its key characteristic is that it encodes data in a way that insures t

MAP

Manifold absolute pressure

Margining is a test procedure that determines the "safety margin." A parameter is varied to determine the device's sensitivity or ability to perform given a range of inputs. A large number of parts can be characterized to determine a safe range for the sp

Maximum differential nonlinearly expressed in least significant bit(s).

When switching between sample mode and hold mode, charge injection from stray capacitance causes the maximum voltage of the hold capacitor to change.

"Max. INL (±%FSR)" is the maximum integral nonlinearity, expressed as a percentage of full-scale range.

Maximum time-on

MBB

Make-before-break: In a switching device, a configuration in which the new connection path is established before the previous contacts are opened. This prevents the switched path from ever seeing an open circuit.

MBC

Main booster converter

MC

Multicommunicator

MCM

1. Multi-Chip Module (MCM): An integrated circuit package that contains two or more interconnected chips.

1. Megacycles per second (obsolete): Megahertz

Multiplying digital-to-analog converter

A parallel digital bus used for 10Mbps and 100Mbps Ethernet.

RS-232 logic-level compatible data rates that are 1Mbps or higher.

Acronym for "Micro Electronic Mechanical Systems," or microelectromechanical systems: Systems that combine mechanical and electrical components and are fabricated using semiconductor fabrication techniques. Common examples are pressure and acceleration se

A Metal-Semiconductor Field-Effect-Transistor uses a metal-semiconductor (Schottky) junction to create the conductive channel, rather than using a p-n junction as a JFET does; or a metal-oxide-semiconductor layer as a MOSFET uses.

A Metal Oxide Varistor (MOV, or surge-suppressor) is a discrete electronic component that diverts excessive voltage to the ground and/or neutral lines.

Multiple frequency-shift keying

MHz

Megahertz (MHz): Measurement of frequency -- million cycles per second.

A Micro Energy Cell (MEC) is a small, rechargeable, very long life, energy storage device used in energy harvesting applications.

A small computer on a single integrated circuit. In modern terminology, it is similar to, but less sophisticated than, a system on a chip or SoC.

A 1-Wire network. A low-cost network in which PCs or microcontrollers communicate digitally over twisted-pair cable using 1-Wire components.

A device that monitors three conditions vital to processor-controlled systems: power supply, software execution, and external override.

A device that monitors a host microprocessor or microcontroller's supply voltage and, in some cases, its activity. It monitors for a fault condition and takes appropriate action, usually issuing a reset to the microprocessor.

A Multiple Input, Multiple Output (MIMO) system has multiple antennas and multiple radios. It takes advantage of multipath effects, where a transmitted signal arrives at the receiver through a number of different paths. Each path can have a different time

The minimum sensitivity attainable with a programmable loss-of-signal feature.

The minimum closed-loop gain for which the amplifier is stable.

Master-in, slave-out isolated input

Master-in, slave-out isolated output

A mixed-signal integrated circuit is any integrated circuit that has both analogcircuits and digital circuits on a single semiconductor die.

mm

Millimeter(s)

A sequence increases monotonically if for every n, Pn + 1 is greater than or equal to Pn. Similarly, a sequence decreases monotonically if for every n, Pn + 1 is less than or equal to Pn.

Metal-oxide semiconductor field-effect transistor; metal-oxide silicon field-effect transmitter.

Master Out Slave In: One of the four Serial Peripheral Interface (SPI) pins.

MPU

Microprocessing unit

MPW

Multiproject wafer

Metric quad flat pack

Milliradian(s)

ms

Millisecond(s)

MSA

Measurement Systems Analysis is a method for ensuring product test measurements are reliable, robust, and of good statistical merit.

MSB

Most-significant bit. In a binary number, the MSB is the most weighted bit in the number. Typically, binary numbers are written with the MSB in the left-most position; the LSB is the furthest-right bit.

Megasamples per second: A measure of speed in digitizing systems, samples per second dictates the maximum frequencies that can be accurately captured.

Multitone intermodulation distortion

Multitone power ratio

In radio transmission, multipath refers to the simultaneous reception of two copies of the signal, that arrive via separate paths with different delays.

1. Combining two signals (which can be analog or a digital stream) into one in such a way that they can later be separated. Examples are OFDM; standard FM stereo broadcast (in which left and right are multiplexed onto one baseband signal); standard televi

mV

A millivolt (mV) is 1/1000 of a volt.

mW

Milliwatt(s)

MW

Megawatt(s)

nA

Nanoampere(s)

Nanovolt (nV): Unit of measure. A billionth of a volt.

NC

Normally closed (switch contacts)

NF

Noise figure

NIC

Network interface card

Nickel metal hydride: A rechargeable-battery technology.

NMI

Nonmaskable interrupt

An n-channel metal-oxide semiconductor (nMOS) transistor is one in which n-type dopants are used in the gate region (the "channel"). A positive voltage on the gate turns the device on.

NO

Normally open (Switch contact)

Nonvolatile (NV) RAM is memory which retains its stored value when power is removed.

A combination of inert and corrosive gases usually associated with exhaust fumes or industrial by-products gases which can cause corrosive effects on temperature and pressure sensors when exposed.

NPR

Noise-power ratio

NRD

Nonradiative dielectric

NRE

Nonrecurring engineering — one-time engineering costs associated with a project.

NRZ

Non Return to Zero: A binary encoding scheme in which ones and zeroes are represented by opposite and alternating high and low voltages, and where there is no return to a zero (reference) voltage between encoded bits. That is, the stream has only two valu

ns

Nanosecond(s)

NTC

Negative temperature coefficient

nth

A tiny, tiny amount. Pronounced "enth." From 1/n, which is one "nth."

NTSC is the color television standard established by the National Television Standards Committee in the United States in 1953. The NTSC standard's distinguishing feature was that it added color to the original 1941 black and white television standard in s

Nanovolt seconds

nW

Nanowatt(s)

In A/D conversion, the Nyquist principle (derived from the Nyquist-Shannon sampling theorem) states that the sampling rate must be at least twice the maximum bandwidth of the analog signal in order to allow the signal to be reproduced. The maximum bandwid

OC

Overcurrent

A fiber-optic line capable of 2400 megabits per second.

OEM

Original equipment manufacturer

OFC

Open fiber control

Orthogonal Frequency Division Multiplexing: A method for multiplexing signals which divides the available bandwidth into a series of frequencies known as tones. Flarion uses the 5GHz channel and divides each channel into 400 discrete tones (each at slight

Organic Light-Emitting Diode: An LED made with organic materials. The diodes in displays made with OLEDs emit light when a voltage is applied to them. The pixel diodes are selectively turned on or off to form images on the screen. This kind of display can

OLT

Optical line transmission

ONU

ONT (Optical Network Termination), also called ONU (Optical Network Unit), refer to the consumer end equipment in an optical Fiber to the Home (FTTH) link. The ONT/ONU receives downstream data from the OLT (Optical Line Termination) through the passive op

Operational amplifier: The ideal op amp is an amplifier with infinite input impedance, infinite open-loop gain, zero output impedance, infinite bandwidth, and zero noise. It has positive and negative inputs which allow circuits that use feedback to achiev

An open-drain or open-collector output pin is driven by a single transistor, which pulls the pin to only one voltage (generally, to ground). When the output device is off, the pin is left floating (open, or hi-z). A common example is an n-channel transist

An optical fiber is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair.

An opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light.

Optoelectronic devices and components are p-n junction those electronic devices that operate on both light and electrical currents.

OR

Combining two signals so that the output is on if either signal is present. This can be accomplished by an OR logic gate (two inputs, one output which is high if either input is).

The ratio between the sensed current and the output current of the amplifier.

Overcurrent or excess current is a situation where a larger than intended electric current exists through a conductor, leading to excessive generation of heat, and the risk of fire or damage to equipment.

Overvoltage Protector (OVP) refers to a circuit that protects downstream circuitry from damage due to excessive voltage. An OVP monitors the DC voltage coming from an external power source, such as an off-line power supply or a battery, and protects the t

P-P

Peak-to-peak

pA

Picoampere(s)

PA

Power amplifier: An amplifier used to drive significant power levels. An audio amplifier that drives a loudspeaker and the final stage of a transmitter are common examples.

A semiconductor package is a metal, plastic, glass or ceramic casing containing one or more semiconductor electronic components.

PAE

Power-added efficiency

PAL

Phase alternate line: A television standard used in most of Europe. Similar to NTSC, but uses subcarrier phase alternation to reduce the sensitivity to phase errors that would be displayed as color errors. Commonly used with 626-line, 50Hz scanning system

A parallel interface (as distinguished from a serial interface) is one in which data is sent on several wires (or several wireless channels) at once. Examples: GPIB, byte-wide parallel interfaces to data converters, memory and data buses on computer board

The device derives its supply power directly from the serial interface (1-Wire).

The ability to lockout writes and/or reads to certain sections of the memory.

Passive components include two-terminal components such as resistors,capacitors, inductors, and transformers.

PBC

Port bypass circuit

pC

1. pC: Picocoulomb(s), a unit of electrical charge. 

Add-in cards that conform to the PC Card specification (formerly called PCMCIA). A PC Card is a removable device, approximately the size of a credit card, designed to plug into a matching slot.

PCB

"Printed Circuit Board" … Conductive pathways are etched or "printed" onto board, connecting different components on the PCB, such as transistors, resistors, and integrated circuits.

PCI

Peripheral Component Interconnect: A standard interface used primarily on computer backplanes to connect interface cards and peripheral devices to the processor bus. PCI is often used for video display cards, network interfaces (e.g. Ethernet), and periph

PCI Express® (Peripheral Component Interconnect Express), officially abbreviated as PCIe®, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP standards. It is used to link motherboard-mounted peripherals and as an expa

PCM

Pulse-Code Modulation (PCM) is the conversion of an analog signal (e.g. audio) into digital, binary (0 or 1), coded pulses, decreasing noise susceptibility. PAM, PFM and PWM are examples of PCM methods.

Personal Computer Memory Card International Association: A standard for miniaturized laptop expansion cards for modems, storage, and other devices. The standard was officially renamed "PC card."

PDC

Personal Digital Cellular: The digital wireless standard used in Japan. PDC uses TDMA air interface.

PDI

Phase-detector input

PDJ

Pattern-dependent jitter

PDM

Pulse density modulation

PDO

Phase-detector output

Peak Inverse Voltage (PIV) or Peak Reverse Voltage (PRV) refer to the maximum voltage a diode or other device can withstand in the reverse-biased direction before breakdown. Also may be called Reverse Breakdown Voltage.

Positive-referenced emitter-coupled logic

pF

Picofarad. A Farad is the unit of capacitance. A pF is 10-12 of a Farad. (1000pF = 1nF, 1000nF = 1 microfarad).

PFD

Phase/frequency detector

PFI

Power-fail input

PFM

Pulse-Frequency Modulation: A pulse modulation technique in which the frequency is varied with the input signal amplitude. The duty cycle of the modulated signal does not change. Because it is always a square wave with changing frequency, PFM is also refe

Process Failure Mode and Effects Analysis (PFMEA): A methodology for assessing the weaknesses of production processes and the potential effects of process failures on the product being produced.

PFO

Power-fail output

PG

Power-good; power gain

PGA

Programmable Gain Amplifier: An amplifier whose gain can be varied by a separate input (usually a digital value).

A photodiode is a semiconductor device that converts light into an electrical current. 

Photovoltaics (PV) is a term which covers the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry.

Electronic circuitry in an automated tester (ATE system) that connects to the device under test.

PKI

Public Key Infrastructure: A combination of standards, protocols, and software that creates, edits, and revokes digital public key certificates.

PLC

A Programmable Logic Controller (PLC, or Programmable Controller) is a ruggedized, microprocessor-based system which provides factory or plant automation by monitoring sensors and controlling actuators in real time.

Leaded Chip Carrier, also called PLCC or Plastic Leaded Chip Carrier: A square surface mount chip package in plastic with leads (pins) on all four sides.

The time-division multiplexed network used by telecommunications companies to transport phone calls and data over copper cabling. The entire network shares a common frequency throughout it's tree-like structure, although phase and time delay variations ex

PLL

A phase-locked loop (PLL, or phase lock loop) is a control system that generates a signal that has a fixed relation to the phase of a "reference" signal. A phase-locked loop circuit responds to both the frequency and the phase of the input signals, automa

PLM

Pad limiting metal

PMBus is an open standard power-management protocol.

Power Management Integrated Circuit: Circuits used to regulate and control power.

PMM

Power-management mode

Pmods™ are small I/O interface boards used to extend the capabilities of FPGA/CPLD and embedded control boards. Pmods communicate with system boards using 6- or 12-pin connectors.

A p-channel metal-oxide semiconductor (pMOS) transistor is one in which p-type dopants are used in the gate region (the "channel"). A negative voltage on the gate turns the device on.

PMR

Private Mobile Radio: Radio bands generally for use within a defined user group, such as the emergency services or by the employees of a mining project.

PoE

Power-over-Ethernet: A means for delivering power to a remote device using the same cable lines used to deliver Ethernet data.

Point-of-load (POL) power supplies solve the challenge of high peak current demands and low noise margins, required by high-performance semiconductors such as microcontrollers or ASICs, by placing individual power supply regulators (linear or DC-DC) close

POK

Power-OK

PON

Passive optical network: A cost-effective way to provide high performance Fiber to the Home (FTTH) connectivity via shared optical fiber. PON connects up to 32 (or more) homes on the same network using passive optical components (splitters).

Periodic Operating Point (POP) Analysis is a simulation technique (used by EE-Sim) to find the steady state operation condition of a switching power supply design.

POR

Power-on reset

Variable resistor in which a wiper sweeps from one end of the resistive element to the other, resulting in resistance that is proportional to the wiper's position.

In an RF power amplifier, power added efficiency (PAE) is defined as the ratio of the difference of the output and input signal power to the DC power consumed. In other words:

Power conversion is converting electric energy from one form to another such as converting between AC and DC; or just changing the voltage or frequency; or some combination of these.

Electric power distribution is the final stage in the delivery of electric power; it carries electricity from the transmission system to individual consumers. 

Power factor correction (PFC) is used in computer power supplies. PFC is applied to the circuits that include induction motors as a means of reducing the inductive component of the current and thereby reduce the losses in the supply.

A feature in a microprocessor supervisory circuit that provides early warning to the microprocessor of imminent power failure.

Power IC properties that differentiates it from other semiconductor technologies is its ability to handle high voltage, high current, or a combination of both.

Power management integrated circuits (power management ICs or PMICs or PMU as unit) are integrated circuits (or a system block in a system-on-a-chip device) for managing power requirements of the host system.

Electrical Units of Measure. The standard units of electrical measurement used for the expression of voltage, current and resistance are the Volt [ V ], Ampere [ A ] and Ohm [ ? ] respectively.

A power module or power electronic module provides the physical containment for several power components, usually power semiconductor devices.

A power MOSFET is a specific type of metal oxide semiconductor field-effect transistor (MOSFET) designed to handle significant power levels. ... Thepower MOSFET is the most widely used low-voltage (that is, less than 200 V) switch.

Electric power quality, or simply power quality, involves voltage, frequency, and waveform. 

A power semiconductor device is a semiconductor device used as a switch or rectifier in power electronics; a switch-mode power supply is an example. Such a device is also called a power device or, when used in an integrated circuit, a power IC.

A power supply is an electrical device that supplies electric power to an electrical load.

A special surface-mount package with access to the internal cavity via an openable top. This packaging scheme allows easy upgrade of NV RAMs without having to change the PCB hardware layout. The user can simply open the lid and swap out the IC.

Production Part Approval Process. Used by automotive industry for acceptance of new products for release and use on automobiles.

Pseudorandom binary (bit) sequence

PRC

Parasitic resistance cancellation

Parasitic resistance cancellation mode

A power-supply feature that prevents discharging of the output capacitor when the power supply starts up. Discharging the output capacitor could create either start up oscillation problems at cold start or large voltage disturbances on the output voltage

In some transmission and recording systems (e.g. vinyl records, FM radio, analog magnetic tape), there is more noise at higher frequencies. To offset this, the audio signal is "preemphasized" at the transmitter -- filtered with a high-pass filter to boost

A Pressure Cooker Test (PCT) tests a part under high temperature, humidity, and pressure conditions. Also called an Autoclave Test or Pressure Pot Test (PPOT).

A printed circuit board, or PC board, or PCB, is a non-conductive material with conductive lines printed or etched. Electronic components are mounted on the board and the traces connect the components together to form a working circuit or assembly.

PRM

Performance report message

Digital output pin on Intel's Pentium 4 processors that indicates the internal Thermal Control Circuit has activated. This occurs when the processor has reached its maximum safe operating temperature.

Vendor-independent open fieldbus standard used in manufacturing, building automation, and process control. Utilizes a nonpowered two-wire (RS-485) network. PROFIBUS is standardized under the European Fieldbus Standard EN 50 170. It includes three versions

Programmable read-only memory

PRT

Platinum Resistance Thermometer, a resistance temperature device (RTD).

PS

Power sense

PSD

Preamble-switched diversity

PSK

Phase-shift keying (PSK): A modulation technique in which the phase of the carrier conveys the input signal's information.

PSR

Power-supply rejection

Power Supply Rejection Ratio (PSRR) is the ability of an amplifier to maintain its output voltage as its DC power-supply voltage is varied.   PSRR = (change in Vcc)/(change in Vout)

PSW

Program status word

PTC

Positive Temperature Coefficient (PTC): When the resistance of a component rises with temperature, it is said to have a positive temperature coefficient.

Pulse-Amplitude Modulation (PAM) is a pulse modulation technique in which the amplitude of the pulse is varied with the input signal amplitude.

Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a modulation technique used to encode a message into a pulsing signal.

An output structure which uses one active device to source current and a second device to sink current. Common examples are: a CMOS stage in which an n-channel device pulls toward ground or a negative supply and a p-channel device pushes current to bring

Picovolt second(s)

PWD

Pulse-width distortion

PWM

1. A method for using pulse width to encode or modulate a signal. The width of each pulse is a function of the amplitude of the signal.

Temperature sensor with digital, logic-level output. The output has a fixed frequency and the duty cycle varies with the measured temperature.

A measure of the quality of a resonant (tank) circuit. A "high-Q" circuit has mostly reactive components (inductive and capacitive), with low resistance. It resonates strongly, with little damping (low loss). A high-Q circuit will have low bandwidth relat

QAM

Quadrature Amplitude Modulation: A modulation method in which two signals are used to amplitude-modulate two carriers that are in quadrature (90 degrees out of phase with each other). The two modulated signals are combined.

QFN

"Quad, flat, no-lead" package.

QFP

Quad flat pack, a package type.

Quadrature Phase Shift Keying (QPSK) is a form of Phase Shift Keying in which two bits are modulated at once, selecting one of four possible carrier phase shifts (0, 90, 180, or 270 degrees). QPSK allows the signal to carry twice as much information as or

Quasi-random signal source

QS-9000 is the automotive quality standard surperseded by ISO/TS16949:2002 specification for component suppliers to the automotive industry.

Quarter small-outline package

The relation between two waves of the same frequency, but one-quarter of a cycle (90°) out of phase.

A process whereby the continuous range of input-signal values is divided into nonoverlapping subranges. Each of these subranges has a discrete value of the output uniquely assigned. Once a signal value falls within a given subrange, the output provides th

Software that examines bias and transient simulation output and flags devices operating above limits.

For an electronic circuit, a quiet state in which the circuit is driving no load and its inputs are not cycling. Most commonly used for the specification "quiescent current," the current consumed by a circuit when it in a quiescent state.

1. Short for R-2R ladder: A method for D/A conversion which employs a ladder-shaped resistor array composed of two resistor values: R and 2R. Each bit in the digital input switches a ladder's rungs in and out of the network to change the output voltage by

RAC

Remaining absolute capacity (mA-hr)

Redundant Array of Independent Disks: A redundant array of inexpensive disks. RAID is a performance-enhancing method of storing the same data in different places on multiple hard disks to achieve speed and/or data redundancy.

The allowable input signal range includes the supply voltages.

The allowable input and output voltage ranges include the power-supply rails.

RAM

Random access memory

Random jitter (RJ) includes all jitter components not defined as deterministic jitter (i.e., the jitter that is not related to the signal and known noise sources).

RAR

Remaining active runtime (min)

RC

Resistance-capacitance; resistor-capacitor. In particular, an RC network is a network composed of resistors and capacitors in a series-parallel combination, usually to filter or delay a signal.

RE

Remaining energy (joules)

A circuit that accepts signals from a transmission medium (which can be wireless or wired) and decodes or translates them into a form that can drive local circuits.

The time for a sensor to return to baseline value after the step removal of the measured variable. Usually specified as time to fall to 10% of final value after step removal of measured variable.

A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction.

REF

REF is a term that appears on IC package drawings in reference to dimensions. It stands for REFERENCE and indicates that this is a reference dimension, calculated or based on another dimension.

A voltage reference is an electronic device which produces a constant voltage regardless of the loading on the device, temperature changes, passage of time and power supply variations. The voltage reference circuit most commonly used in integrated circuit

Reference design refers to a technical blueprint of a system that is intended for others to copy. It contains the essential elements of the system; however, third parties may enhance or modify the design as required. When discussing computerdesigns, the c

A regulated power supply is an embedded circuit; it converts unregulated AC into a constant DC. With the help of a rectifier it converts AC supply into DC. Its function is to supply a stable voltage (or less often current), to a circuit or device that mus

A relay is an electromagnetic switching device consisting of an armature which is moved by an electromagnet to operate one or more switch contacts.

A diode or diode-connected bipolar transistor used as a temperature-sensing element, often integrated onto an integrated circuit whose temperature is to be measured.

Temperature at a location other than at the die of the temperature-measuring integrated circuit.

A remotely located PN junction used as a temperature sensing device, usually located on an integrated circuit other than the one doing the measurement.

Resistance, represented by the symbol R and measured in ohms, is a measure of the opposition to electrical flow in DC systems. Resistance is the voltage across an element divided by the current (R = V/I).

A resistor is a passive two-terminal electricalcomponent that implements electrical resistance as acircuit element.

A resonant, or tuned, circuit combines an inductor and capacitor (or mechanical equivalents such as a crystal or MEMS oscillator) to make a circuit that is responsive to a frequency. Depending on the configuration, the circuit can have a high or low imped

The time for a sensor to respond from no load to a step change in load. Usually specified as time to rise to 90% of final value, measured from onset of step input change in measured variable.

When switching from the conducting to the blocking state, a diode or rectifier has stored charge that must first be discharged before the diode blocks reverse current. This discharge takes a finite amount of time known as the Reverse Recovery Time, or trr

RF

Radio Frequency: An AC signal of high enough frequency to be used for wireless communications.

A radio frequency power amplifier (RF power amplifier) is a type ofelectronic amplifier that converts a low-power radio-frequency signal into a higher power signal.

Also known as over-the-air wireless charging. Unlike inductive charging, RF charging doesn't require intimate contact, but the power transfer is less efficient.

Radio frequency design system

RFI

Radio Frequency Interference: Unwanted noise from RF sources.

Radio Frequency Identification: A method for uniquely identifying an object using a tag or module that carries a unique ID number, or code. Identification can be made using wireless (RF, or radio-wave) connection, meaning no line-of-sight or physical cont

Positive reference

RH

Relative humidity

RI

Reference input; ring indicate

Recording Industry Association of America

Ripple Rejection is the ability of an amplifier to maintain accurate output voltage despite AC fluctuations in the power supply.

Reduced instruction set computer (RISC): Computer hardware designed to support a short list of simple instructions. This makes the hardware simpler and faster, since it does not need to accommodate complex instructions.

RMS

Root mean square

Negative reference

ROM

Read-only memory

RRC

Remaining relative capacity: The percent of the full charge that remains in a power cell.

A serial interface published by the EIA for asynchronous data communication over distances up to a few hundred feet. Characterized by a single-ended (not differential) physical layer, it uses one signal wire for transmission, another for reception, and a

RS-485 and RS-422 are serial interface standards in which data is sent in a differential pair (two wires, or twisted pair cable), which allows greater distances and higher data rates than non-differential serial schemes such as RS-232.

RSA

A public key cryptographic algorithm named after its inventors (Rivest, Shamir, and Adelman). It is used for encryption and digital signatures. RSA was developed in 1977 and is today the most commonly used encryption and authentication algorithm.

RSR

Remaining standby runtime (min)

Received Signal Strength Indicator (or Indication): A signal or circuit that indicates the strength of the incoming (received) signal in a receiver. (The signal strength indicator on a cell phone display is a common example).

Real-time clock: Integrated circuit that contains a timer that supplies the time of day (and often, the date). An RTC generally contains a long-life battery to allow it to keep track of the time even when there is no power applied.

RTD

A Resistance Temperature Detector (RTD) is a device with a significant temperature coefficient (that is, its resistance varies with temperature). It is used as a temperature measurement device, usually by passing a low-level current through it and measuri

RTS

Request to send: A data communications signal (e.g. RS-232)

Rx

Receive

RZ

Return to Zero: A binary bitstream encoding scheme in which the signal returns to zero voltage in between the data bits. The signal has three valid levels: High, Low, and the return to zero volts after each bit.

S

1. Siemen(s), standard unit for conductance

The reflection and transmission coefficients used in impedance matching between high-speed (RF) devices and transmission lines/traces.

Satellite-universal mobile telecommunications system

S/S

Single supply

sps: Samples per second. In data conversion, an analog signal is converted to a stream of numbers, each representing the analog signal's amplitude at a moment in time. Each number is called a "sample." The number sample per second is called the sampling r

An A/D converter converts an analog signal into a stream of digital numbers, each representing the analog signal's amplitude at a moment in time. Each number is called a "sample." The number sample per second is called the sampling rate, measured in sampl

SAN

Storage Area Network: A network infrastructure of shared multihost storage, linking all storage devices and interconnecting remote sites.

SAR

Successive Approximation Register: Used to perform the analog-to-digital conversion in successive steps in many analog-to-digital (ADC) converters.

SAW

Surface Acoustic Wave: A sound wave that propagates along the surface of a solid and is contained within the solid. SAW devices typically combine compressional and shear components. In Wireless applications, SAW refers to a Surface Acoustic Wave band-pass

Super ball-grid array, a packaging technology.

SBS

Smart Battery Specification: A specification developed by Duracell.

A design technique in which the internal registers or flip-flops of a circuit can be chained, to allow an external circuit to easily read and write their contents.

Also known as Euroconnector or Peritel, a 21-pin connector commonly used in Europe to interconnect satellite receivers, television sets, and other audiovisual equipment (e.g. videocassette recorders). A single connector combines audio and video signals. T

SCF

Switched-capacitor filter

A diode realized via a "Schottky-barrier junction" -- a metal-semiconductor junction -- rather than the P-N junction used by conventional semiconductor diodes. Schottky diodes are often chosen for their high switching speed and low forward voltage drop.

SCL

Serial clock line

Serial clock

SCR

Silicon-controlled rectifier

Small Computer System Interface (pronounced "scuzzy"), an interface standard for connecting peripheral devices to computers. Hardware components for implementing a SCSI interface include connector ports on computers and cables for connecting peripheral de

SCT

Single Chip Transceivers: A single IC that includes data communication transmitter and receiver functions.

SD

1. Signal detect: An output that indicates when a signal is present. A form of Signal Strength Indicator.

SDA

Serial data access

SDO

Serial data out

Standard Definition Television: Digital formats that do not achieve the video quality of HDTV, but are at least equal, or superior to, NTSC pictures. SDTV may have either 4:3 or 16:9 aspect ratios, and includes surround sound. Variations of fps (frames pe

Second harmonic distortion (HD2): Ratio of second-order harmonic to the input signal (carrier). Often measured as dBc.

This standard specifies a Secure Hash Algorithm, SHA-1, for computing a condensed representation of a message or a data file.

1. A substance that can act as an electrical conductor or insulator depending on chemical alterations or external conditions. Examples are silicon, germanium, and gallium arsenide.

A resistor placed in a current path to allow the current to be measured. The voltage across the sense resistor is proportional to the current that is being measured and an amplifier produces a voltage or current that drives the measurement.

In the broadest definition, a sensor is a device, module, or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronics, frequently a computer processor.

Single Ended Primary Inductor Converter: A DC-DC converter topology that acts both as a boost and a buck converter (that is, will step up or down, depending on the input voltage).

The single-ended primary-inductor converter (SEPIC) is a type of DC/DC converter that allows the electrical potential (voltage) at its output to be greater than, less than, or equal to that at its input.

Serialization/deserialization

A serial interface (as distinguished from a parallel interface) is one in which data is sent in a single stream of bits, usually on a single wire-plus-ground, wire-pair, or single wireless channel (or two sets, one for each direction). Examples include US

Spurious-Free Dynamic Range: A term used to specify A/D and D/A converters (ADCs and DACs).

SFF

Small Form Factor: An optical module.

Small Form Factor: Specification for optical modules.

SFP

Small Form Factor Pluggable

SFR

Special-function register

SHA

Secure Hash Algorithm: A message digest algorithm developed by the NSA for use in the Digital Signature standard, FIPS number 186 from NIST. SHA is an improved variant of MD4 producing a 160-bit hash. SHA is one of two message digest algorithms available

Shutdown. Low-power standby mode.

Two or more bistable elements (flip-flops) connected in series. With each tick of the clock, the output of stage n is shifted to stage n+1. Applications include clock or signal delays, delay lines, linear-feedback shift registers.

An acceleration sensor, generally a piezoelectric type, that can measure high acceleration but cannot measure static g forces.

In a push-pull amplifier stage, one transistor pushes current to the output to drive it toward a positive voltage; a second device pulls down. These are designed so both devices are never fully on, which would effectively short the power supply.

A feature of many ICs, typically controlled via a logic-level input, which dramatically reduces power consumption when the device is not in use.

SI

Sampled input

Silicon Germanium process

Signal invalid output. Indicates when all RS-232 signals to the IC are in the invalid range.

Signal-to-Noise Ratio, the ratio of the amplitude of the desired signal to the amplitude of noise signals at a given point in time. The larger the number, the better. Usually expressed in dB.

Silicon carbide (SiC), also known as carborundum /k??rb??r?nd?m/, is a semiconductor containing silicon and carbon with chemical formula SiC.

SIM

Subscriber identity module

Electronic circuit simulation uses mathematical models to replicate the behavior of an actualelectronic device or circuit

Signal-to-noise and distortion ratio: The RMS value of the sine wave f(IN) (input sine wave for an ADC, reconstructed output sine wave for a DAC) to the RMS value of the converter noise from DC to the Nyquist frequency, including harmonic content. It is t

System loopback input

Subscriber-Loop-Interface-Circuit: A telephone line interface.

A battery with internal circuitry that provides level of charge status to the host system.

A phone with a microprocessor, memory, screen, and built-in modem. The smart phone combines some of the capabilities of a PC in a handset device and typically include Internet connectivity.

Signal conditioner that is programmable or has a flexible architecture to allow it to accomplish sophisticated signal transformations and corrections.

System Management Bus: A 2-wire serial-interface standard developed by Intel.

SMD

1. Surface Mount Device (SMD): An electronic component that mounts on the surface of a printed circuit board (as opposed to "through-hole" components which have pins that are inserted into holes). SMDs typically allow more components per square centimeter

Switch-Mode Power Supply

SMR

Specialized Mobile Radio: Indicates the 896MHz to 901MHz band (800MHz band), which uses two paired 25kHz channels, and the 935MHz to 940MHz band (900 MHz band), which uses two paired 12.5kHz channels. Ten 20-channel blocks have been allocated in these fre

A device which suppresses voltage transients.

SO

Small outline (a package type).

SOC

State of change

A feature in some switching power supplies that limits the startup inrush current at initial startup.

Small Office/Home Office: Businesses that are either run from home or a from a small office. Software and hardware companies sometimes promote products as suitable for the SOHO market.

Small outline integrated circuit, a packaging technology.

A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

A solid state device or circuit is one that relies on semiconductors rather than mechanical or vacuum tube circuits.

Solid-state lighting (SSL) refers to a type of lightingthat uses semiconductor light-emitting diodes (LEDs), organic light-emitting diodes (OLED), or polymer light-emitting diodes (PLED) as sources of illumination rather than electrical filaments, plasma

Synchronous Optical Network: A North American standard for transmission in synchronous optical networks. It defines a family of rates, formats, interfaces, transport options, and maintenance capabilities. The minimum rate for SDH is 155Mbps.

SOT

Small outline transistor

In radio systems, Space Diversity transmits a signal on multiple propagation paths.

SPC

Statistical process control

Service Control Peripheral Register

Service Control Data Register

Single-pole/double-throw switch

Signal power functional part

SPI

Serial Peripheral Interface. A 3-wire serial interface developed by Motorola.

Simulation program with integrated circuit emphasis

A technology that modulates a signal over many carrier frequencies at once. This method can be used to make transmissions more secure, reduce interference, and improve bandwidth-sharing.

Single-pole/single-throw switch

Unwanted frequencies are not present.

SQC

Statistical quality control: Use of statistical methods to measure and improve the quality of manufacturing processes and products. The term "statistical process control" is often used interchangably.

SR

Slew rate

Static RAM: RAM that does not require a clock to retain its contents.

SRF

Self-resonant frequency

SS

Soft-start; sample size

SSC

Smart signal conditioning

Shrink small-outline package

A pcb layout technique in which all components connect to ground at a single point. The traces make in a "star" pattern, emanating from the central ground.

A point from which all traces leave in a "star" pattern in pcb layout.

STB

A "set top box," or STB, is a generic name for an electronic interface between a cable television or satellite signal and video display and recording devices. Typically a box that can be placed atop the television set (hence the name), it can have many fu

STC

1. Silicon Timed Circuit: A circuit that produces a delayed version of the input signal. Also known as a delay line.

A switch-mode voltage regulator in which output voltage is higher than its input voltage.

A pulse used for timing and synchronization.

A high-capacity capacitor with capacitance values much higher than other capacitors (but lower voltage limits) that bridge the gap between electrolytic capacitors and rechargeable batteries. 

A radio receiver that combines a locally generated frequency with the carrier frequency to produce a lower-frequency signal (IF, or intermediate frequency) that is easier to demodulate than the original modulated carrier.

A method for producing electronic circuits in which the components are mounted or placed directly onto the surface of printed circuit boards (PCBs).

The Swallow Counter is one of the three building blocks (swallow counter, main counter, and dual-modulus prescaler) that constitute the programmable divider commonly used in modern frequency synthesizers.

Shared wireless access protocol

A switch is an electrical component that can "make" or "break" an electrical circuit, interrupting the current or diverting it from one conductor to another.

Uses a switching transistor and inductor to control/regulate the charging voltage/current.

A circuit methodology, typically implemented in CMOS integrated circuits, that uses clocked switches and capacitors to transfer charge from node to node such that a resistor function is realized. The effective resistance is governed by capacitor size and

A voltage regulator that uses a switching element to transform the supply into an alternating current, which is then converted to a different voltage using capacitors, inductors, and other elements, then converted back to DC. The circuit includes regulati

A switched-mode power supply (SMPS) is an electronic circuit that convertspower using switching devices that are turned on and off at high frequencies, and storage components such as inductors or capacitors tosupply power when the switching device is in i

SWT

Set watchdog timeout

Synchronous Digital Hierarchy, SDH: The ITU-TSS International standard for transmitting information over optical fiber.

In switch-mode power supplies, the "steering" diode is replaced or paralleled with a FET switch to reduce losses and thereby increase efficiency. The FET is off during the inductor charge cycle, and then turned on as the inductor discharges into the load.

A System on a Chip (SoC) integrates most of a system's elements on a single integrated circuit (chip). It typically combines a microprocessor core along with interface elements and analog and mixed signal functions.

A system on a chip or system on chip (SoC or SOC) is an integrated circuit (also known as an "IC" or "chip") that integrates all components of a computer or other electronic systems. 

T/H

Track/hold

T/R

Transmit/receive

T1

T1 is standard for digital transmission in the United States. It is a digital transmission link with a capacity of 1.544Mbps. T1 uses two pairs of normal twisted wires, the same as found in most residences. T1 normally handles 24 voice conversations, each

T3

A type of data connection capable of transmitting a digital signal at 44Mbps. T3 lines are often used to link large computer networks, such as those that comprise the Internet.

TAD

Total accumulated discharge (mA-hr)

In a potentiometer, taper refers to how the resistance varies as the pot's armature is rotated (or, for a slide pot, as its wiper slides; or for a solid state pot like the DS1802, as its input voltage is varied).

TC

Temperature coefficient; thermocouple; TURBOCHARGE (control bit)

Transmission Control Protocol/Internet Protocol: The protocols or conventions that computers use to communicate over the Internet.

Temperature Compensated Crystal Oscillator: A crystal oscillator that includes circuitry that compensates for temperature variations, to maintain a more constant frequency.

TDD

Time Division Duplex, the second variation of WCDMA especially suited to indoor environments where there is a need for high traffic density.

TDM

Time Division Multiplexing, a scheme in which numerous signals are combined for transmission on a single communications line or channel. Each signal is broken into many segments, each having very short duration.

Time Division Multiple Access: A method of digital wireless-communications transmission. TDMA allows many users to access (in sequence) a single radio-frequency channel without interference, because it allocates unique time slots to each user within each

TDMoP (TDM over Packets), or TDMoIP (TDM over IP), is the implementation of TDM over a packet-switching network. TDMoIP is a trademark of RAD Communications.

TDR

Time-delay relay

Chinese Third Generation (3G) telecommunications standard. China's government allocated three frequency bands: 1880MHZ to ~1920MHz, 2010MHz to ~2025MHz, and 2300MHz to ~2400MHz.

TEC

A thermoelectric cooler (TEC) is a small cooling device that relies on a Peltier junction. Composed of two conductors made of different materials, a Peltier junction (discovered in 1833 by J.C. Peltier) acts as a heat pump which can cool or warm when curr

A system for transmitting picture and sound over a distance, primarily via the standards for NTSC, PAL, or HDTV.

Temperature coefficient

The average kinetic energy of the atoms or molecules of a body or substance, perceived as warmth or coldness. Measured in degrees Fahrenheit, Celsius, or Kelvin.

An integrated circuit with a digital output that indicates whether a measured temperature is above or below a predetermined threshold.

Temperature sensor that uses an external diode-connected transistor as the sensing element to measure temperatures external to the sensor (for example, on a circuit board or on the die of a CPU). Generally produces a digital output.

A circuit that opens and closes a conductive path based on temperature.

Tesla (abbreviated T) is a measure of magnetic flux density (B-field), named for engineer and inventor Nikola Tesla.

TFT

Thin-film transistor

THB

Temperature/humidity bias

THD

Total Harmonic Distortion (THD): A measure of signal distortion which assesses the energy that occurs on harmonics of the original signal. It is specified as a percentage of the signal amplitude.

Total Harmonic Distortion Plus Noise (THD+N) is the sum of the two most important distortion components. THD is the distortion that occurs on harmonics of the original signal -- it is correlated with the signal. Noise is the more random, uncorrelated dist

Circuit to monitor and control the temperature of something. For example the integrated temperature controller in Intel's processors.

The use of various temperature monitoring devices and cooling methods, such as forced air flow, within a processor or FPGA-based system, to control overall temperature of ICs and internal cabinet temperatures.

The integrated thermal control system used in Intel's processor devices.

Deactivating a circuit when a measured temperature is beyond a predetermined value.

Thermal Diode Anode pin on AMD and Intel processors.

Thermal Diode Cathode pin on AMD and Intel processors.

A temperature-dependent resistor with a high temperature coefficient, usually composed of sintered semiconductor material.

A temperature sensor formed by the junction of two dissimilar metals. A thermocouple produces a voltage proportional to the difference in temperature between the hot junction and the lead wire (cold) junction.

Circuit that indicates whether a measured temperature is above or below a particular temperature threshold or trip point. Used for thermal protection and simple temperature control systems.

Pin name of the thermal trip output pin of AMD processors. The pin is asserted at a nominal die temperature of 125°C.

Pin name of the Thermal Trip digital output on Intel Pentium processors. The pin is asserted at a nominal die temperature of 135 degrees-C.

A three-state, or Tri-State™, output has three electrical states: One, zero, and "Hi-Z," or "open." The hi-Z state is a high-impedance state in which the output is disconnected, leaving the signal open, to be driven by another device (or to be pulled up o

A method for mounting components on a printed circuit board (PCB) in which pins on the component are inserted into holes in the board and soldered in place.

Mounting scheme used for electronic components that involves the use of leadson the components that are inserted into holes drilled in printed circuit boards (PCB) and soldered to pads on the opposite side either by manual assembly (hand placement) or by

A thyristor is a solid-state semiconductor device with four layers of alternating P- and N-type materials.

In radio systems, Time Diversity spreads a signal across multiple channels by placing multiple versions of the signal in different time slots.

Tin whiskers (also called Sn whiskers or metal whiskers) are microscopic, conductive, hair-like crystals that emanate spontaneously from pure tin (especially electroplated tin) surfaces. Whiskers form primarily on elemental metals, but have also been foun

A standard CMOS output structure where a P-channel MOSFET is connected in series with an N-Channel MOSFET and the connection point between the two is the output. The P-FET sits on top of the N-FET like a "totem pole." Both gates are driven by the same sig

Thin version of the QFN package (the JEDEC "W" option) 0.8mm thick.

Thin quad flat pack

A device that contains both a transmitter and receiver.

The gain of a transconductance amplifier (an amp in which a change in input voltage causes a linear change in output current). The basic gain of vacuum tubes and FETs is expressed as transconductance. It is represented with the symbol gm.

An amplifier that converts a voltage to a current. Also known by several other terms (see synonym list). One synonym is OTA, or operational transconductance amplifier, a term that marries the terms transconductance amplifier and operational amplifier.

A Transducer Electronic Data Sheet, or TEDS, is a method for plug-and-play sensor and transducer hook-up in which the sensor's calibration information is stored within the device and downloaded to the master controller when requested. A standardized TEDS

Transfer refers to the amount of data transferred across a digital interface, exclusive of any extra bits used to encode the data.

An inductive electrical device for changing the voltage of alternating current.

Transient intermodulation distortion, or TIM, occurs in amplifiers that employ negative feedback when signal delays make the amplifier incapable of correcting distortion when exposed to fast, transient signals.

An amplifier which converts a current to a voltage. It is a familiar component in fiber-communications modules.

A basic solid-state control device which allows or disallows current flow between two terminals, based on the voltage or current delivered to a third terminal.

A circuit that accepts signals or data in and translates them into a form that can be sent across a medium (transmitted), usually over a distance. The medium can be wireless or wired.

TS 16949 is an ISO Technical Specification that aligns previous American (QS-9000), German (VDA6.1), French (EAQF) and Italian (AVSQ) automotive quality systems standards within the global automotive industry. Together with ISO 9001:2000, ISO/TS 16949:200

Thin small-outline C-lead

Thin small-outline package

Temperature sensor and system monitor

Thin shrink small-outline package

TTC

Temperature conversion sample time

Time remaining to full charge

Two-tone intermodulation distortion

TTL

Transistor-to-transistor logic

A tubular motor is an electric motor embedded in a cylindrical form factor. They are typically used for window shades and blinds, projection screens, awnings, roller doors, etc.

TUE

Total unadjusted error

TVM

Test vector monitor

TVS

Transient Voltage Suppressor: Semiconductor device designed to protect a circuit from voltage and current transients. Typically implemented as a large silicon diode operating in avalanche mode to absorb large currents quickly.

Tweak (or sometimes, "tweek") means to make small adjustments to a system to improve its performance.

Tx

Transmit

uA

Microampere, or microamp: A millionth of an Ampere. Ampere is the basic unit for measuring electrical current.

Universal Asynchronous Receiver-Transmitter: An IC that converts parallel data to serial, for transmission; and converts received serial data to parallel data.

UBM

Underbump metal

Ultra High Frequency filter

UI

Unit interval (used to describe jitter generation); user information; user interface

A SCSI interface label, where 160 refers to the maximum reliable throughput in megabits per second.

UMTS (Universal Mobile Telecommunications System) is a third-generation cellular standard based on the GSM standard and developed by the 3rd Generation Partnership Project (3GPP).

An uninterruptible power supply (UPS) is a device that maintains power in the event of a failure. A UPS commonly includes a battery that is kept charged and ready. When power fails, the battery supplies power, as long as it lasts. When the battery fails,

An uninterruptible power supply or uninterruptible power source (UPS) is an electrical apparatus that provides emergency power to a load when the input power source or mains power fails.

A unique identification technique

A factory-programming service for 1-Wire EPROM chips with customer-specified data. Service provides one serialization file for customers to create identifiers in silicon.

A device which provides frequency conversion to a higher frequency, e.g., in digital broadcast-satellite applications.

URL

Uniform/universal resource locator

USB

Universal Serial Bus (USB): A standard port that enables you to connect external devices (such as digital cameras, scanners, keyboards, and mice) to computers. The USB standard supports data transfer at three rates: low speed (1.5MBps), full speed (12Mbps

USB-C, formally known as USB Type-C, is a 24-pin USBconnector system, which is distinguished by its two-fold rotational-symmetrical connector.

UV

Ultraviolet

Undervoltage lockout

UWB

Ultra-Wideband (UWB) is a communications technology that employs a wide bandwidth (typically defined as greater than 20% of the center frequency or 500MHz). UWB is usually used in short-range wireless applications but can be sent over wires. Ultra-Wideban

V-s

Volt-second(s)

V/F

Voltage-to-frequency

VA

Volt ampere(s)

A varistor is an electronic component with an electrical resistance that varies with the applied voltage. Also known as a voltage-dependent resistor (VDR), it has a nonlinear, non-ohmic current–voltage characteristic that is similar to that of a diode.

Vcc

The supply voltage for a circuit is often given as V plus a double-letter suffix. The double letter is usually related to the lead of the transistors that are commonly connected to that supply or to a resistor that connects to that supply.

VCO

Voltage-Controlled Oscillator: An oscillator device in which output frequency is proportional to its input voltage.

Voltage Controlled, Temperature Compensated Crystal Oscillator: A TCXO which offers the ability to control the oscillation frequency with an analog voltage

Voltage Controlled Crystal Oscillator: An oscillator that uses a crystal to establish its frequency but will vary its frequency as an analog control voltage varies.

Very High Data-Rate Digital Subscriber Line: A method for delivering high-speed digital services on the standard twisted pair used for voice phone lines. VDSH operates at data rates from 12.9Mbps to 52.8Mbps.

VFO

Variable-frequency oscillator

VGA

Variable-gain amplifier

VLF

Very-low frequency

Very-low intermediate frequency

Very large-scale integration (VLSI) refers to an IC or technology with many devices on one chip. The question, of course, is how one defines "many."

VME

VERSAmodule Eurocard, or VMEBus, a microcomputer bus. Standardized in IEC 821, IEEE 1014-1987 and ANSI/VITA 1-1994.

Voice over Internet Protocol: Method for transmission of voice (or fax) calls over the Internet.

Volt (or Volts): Unit of measure for electromotive force (EMF), the electrical potential between two points. An electrical potential of 1 volt will push 1 ampere of current through a 1-ohm resistive load.

A volt-ampere (VA) is the voltage times the current feeding an electrical load. A kilovolt-ampere (kVA) is 1000 volt-amperes.

Voltage, electric potential difference, electric pressure or electric tension (formally denoted ?V or ?U, but more often simply as V or U, for instance in the context of Ohm's or Kirchhoff's circuit laws) is the difference in electric potential between tw

A capacitor charge pump circuit which produces an output voltage which is twice the input voltage.

Voltage Identification Digital, or VID, is a circuit concept developed to provide the central processing unit (CPU) of a computer with the appropriate supply voltage. Instead of having a power supply unit generate some fixed voltage, the CPU uses a small

A circuit which is connected between the power source and a load, which provides a constant voltage despite variations in input voltage or output load.

A voltage regulator is an electronic circuit that provides a stable DC voltage independent of the load current, temperature and AC line voltage variations. 

VOM

Volt-Ohm meter

Peak-to-peak voltage

VPU

VPU is a symbol for the pull-up voltage specification (or "Pullup Supply Voltage").

VRD

Voltage Regulator Down, an Intel standard for voltage regulators which are "down" on the mother board.

VRM

Voltage Regulator Module: An Intel Standard for switching regulator modules.

VS

VCO_SEL (control bit)

Virtual Socket Interface Alliance

VSWR (Voltage Standing Wave Ratio), is a measure of how efficiently radio-frequency power is transmitted from a power source, through a transmission line, into a load (for example, from a power amplifier through a transmission line, to an antenna).

W

Watt (W) is the unit for measuring power. In physics terms, one watt is one Joule of energy transferred or dissipated in one second. Electrical power is calculated as:  Watts = Volts x Amps x Power Factor

Watchdog output flag

Semiconductor manufacturing begins with a thin disk of semiconductor material, called a "wafer." A series of processes defines transistors and other structures, interconnected by conductors to build the desired circuit.

Semiconductor processing facility which turns wafers into integrated circuits. A typical wafer fab employs a series of complex steps to define conductors, transistors, resistors, and other electronic components on the the semiconductor wafer. Imaging step

WAN

Wide Area Network: Any Internet or network that covers an area larger than a single building.

A feature of a microprocessor supervisory circuit that monitors software execution in a microprocessor or microcontroller. It takes appropriate action (assert a reset or nonmaskable interrupt) if the processor gets stuck in an infinite execution loop.

Wb

Weber: A measure of magnetic flux.

Wideband Code Division Multiple Access, a standard derived from the original CDMA. WB-CDMA is the third-generation (3G) mobile wireless technology capable of supporting voice, video, and data communications up to 2Mbps.

WDI

Watchdog input

Watchdog pulse output

WE

Write enable

Wearable technology, wearables, fashionable technology, wearable devices, tech togs, ... It appears prominently in consumer electronics with the popularization of the smartwatch and activity tracker.

WHDI (Wireless Home Digital Interface) is a standard that enables wireless delivery of uncompressed HDTV throughout the home with video rates of up to 1080p in the 5GHz unlicensed band. 

Semiconductor materials like Silicon Carbide (SiC) and Gallium Nitride (GaN) that improve the voltage and frequency performance of devices

A classification of the information capacity or bandwidth of a communication channel. Wideband is generally understood to mean a bandwidth between 64kbits/s and 2Mbit/s.

WiMax (Worldwide Interoperability for Microwave Access) is a "last mile," broadband, wireless access mechanism which can potentially replace DSL and Cable Modem. Defined by the IEEE 802.16 standards.

A device, usually consisting of a pair of voltage comparators, in which output indicates whether the measured signal is within the voltage range bounded by two different thresholds (an "upper" threshold and a "lower" threshold).

A special subset of the watchdog timer feature found on microprocessor supervisory circuits. It is used to monitor software execution and assert a reset or an NMI if the processor gets stuck in a loop. This feature not only looks for periodic transitions

When multiple high-impedance (open-collector or open-drain) output pins are connected to a signal line (e.g. a bus) and the system is designed so no more than one is on, a wired-and signal is achieved. This achieves the equivalent of a logical AND functio

Radio-frequency devices, circuits, or communications methods.

Wireless power transfer (WPT), wireless power transmission, wireless energy transmission, or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link.

Wireless Sensor Network, or WSN, is a network of RF transceivers, sensors, machine controllers, microcontrollers, and user interface devices with at least two nodes communicating by means of wireless transmissions.

Wireless Local Area Network

WLL

Wireless Local Loop: Any method of using wireless communication in place of a wired connection to provide subscribers with standard telephone service.

Write-read

Any method that keeps data from being over-written. It may be a physical obstacle or a file attribute choice that prevents overwriting.

WTA

Wireless Telephony Application: A collection of telephony-specific extensions for call- and feature-control mechanisms that make advanced mobile network services available to end users. WTA essentially merges the features and services of data networks wit

Innovation of the 10 Gigabit Ethernet Task Force. XAUI (pronounced "Zowie") is a ten Gigabit/second interface. The "AUI" portion is borrowed from the Ethernet Attachment Unit Interface. The "X" represents the Roman numeral for ten and implies ten gigabits

XCO

Crystal clock oscillator (XCO): An oscillator that relies on a crystal for its frequency reference. A piezoelectric crystal oscillates at a very stable frequency.

Y/C

Y, C, YUV, Y-Pb-Pr, YCbCr, and Y/C (also known as S-video) are terms that refer to video signal components. The black and white (luminance) portion of the video signal is the "Y" component which, when combined with color components, form a complete pictur

YIG

Yttrium-iron-garnet (YIG) is a ferrimagnetic material used for solid-state lasers and for microwave and optical communications devices.

A zener diode is a diode manufactured to have a specific reverse-breakdown voltage. Its most common use is as a voltage reference.

ZIF

Zero Insertion Force: A class of IC sockets which clamp the IC pins (via a small lever on the side of the socket) after insertion, and thus require no downward force on the IC or its pins to insert it into the socket. Especially useful in applications in

A standard for short-distance, low-data-rate communications using the frequencies and physical and data layers of the IEEE 802.15.4 PHY specification. Created and maintained by the ZIGBEE Alliance Group.

ZS

Zero scale

ZVC

Zero voltage crossing

ZVS

Zero voltage switching

 

 



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