Glossary

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.

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

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.

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.

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.

Data communications equipment; interchangeable with DTE

Discontinuous-conduction mode

Direct conversion receiver

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

Digital data input

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 (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.

Decision feedback equalization

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

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

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 (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

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.

Double-layer capacitor

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

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.

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

Digital microwave radio

Discrete multitone data transmission

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.

Differential phase; also decimal place

Discrete packaging

Digital phase detector

Double-pole/double-throw

Data pointer high

Data pointer low

Digital panel meter

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.

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.

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.

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

Digital terrestrial broadcasting

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

Digital Video Broadcast is a name for digital TV.

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.

Digital cross-connect

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