analog-to-digital converter

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Related to analog-to-digital converter: A/D converter, A/D conversion

analog-to-digital converter

[¦an·əl‚äg tə ¦dij·ət·əl kən′vərd·ər]
A device which translates continuous analog signals into proportional discrete digital signals.

Analog-to-digital converter

A device for converting the information contained in the value or magnitude of some characteristic of an input signal, compared to a standard or reference, to information in the form of discrete states of a signal, usually with numerical values assigned to the various combinations of discrete states of the signal.

Analog-to-digital (A/D) converters are used to transform analog information, such as audio signals or measurements of physical variables (for example, temperature, force, or shaft rotation) into a form suitable for digital handling, which might involve any of these operations: (1) processing by a computer or by logic circuits, including arithmetical operations, comparison, sorting, ordering, and code conversion, (2) storage until ready for further handling, (3) display in numerical or graphical form, and (4) transmission.

If a wide-range analog signal can be converted, with adequate frequency, to an appropriate number of two-level digits,or bits, the digital representation of the signal can be transmitted through a noisy medium without relative degradation of the fine structure of the original signal. See Computer graphics, Data communications, Digital computer

Conversion involves quantizing and encoding. Quantizing means partitioning the analog signal range into a number of discrete quanta and determining to which quantum the input signal belongs. Encoding means assigning a unique digital code to each quantum and determining the code that corresponds to the input signal. The most common system is binary, in which there are 2n quanta (where n is some whole number), numbered consecutively; the code is a set of n physical two-valued levels or bits (1 or 0) corresponding to the binary number associated with the signal quantum.

The illustration shows a typical three-bit binary representation of a range of input signals, partitioned into eight quanta. For example, a signal in the vicinity of 3/8; full scale (between 5/16 and 7/16) will be coded 011 (binary 3).

A three-bit binary representation of a range of input signalsenlarge picture
A three-bit binary representation of a range of input signals
References in periodicals archive ?
LISBON, Portugal -- Chipidea[R], the world leader in analog/mixed-signal merchant technology, is the first IP company to introduce a wide-ranging portfolio of sigma-delta analog-to-digital converters that are programmable for either high-performance or low power consumption for a multitude of applications ranging from cellular communications to mobile TV, FM radio, WiFi and more.
The company's Linearizer IC and Analog to Digital Converter (ADC) modules, based on the proprietary Turbolinear(TM) technology, correct for nonlinear distortion generated in high-speed analog-to-digital converters.
NYSE: ADI), the world leader in data converter technology, announced today that it is extending its family of high-speed, multi-channel analog-to-digital converters (ADCs) with the introduction of the industry's first high-speed, 14-bit data converter with four analog-to-digital conversion channels (quad ADC).