instrumentation amplifier


Also found in: Acronyms, Wikipedia.

instrumentation amplifier

[‚in·strə·men′tā·shən ′am·plə‚fī·ər]
(electronics)
An amplifier that accepts a voltage signal as an input and produces a linearly scaled version of this signal at the output; it is a closed-loop fixed-gain amplifier, usually differential, and has high input impedance, low drift, and high common-mode rejection over a wide range of frequencies.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

Instrumentation amplifier

A special-purpose linear amplifier, used for the accurate amplification of the difference between two (often small) voltages, often in the presence of much larger common-mode voltages, and having a pair of differential (usually high-impedance) input terminals, connected to sources Vin1 and Vin2; a well-defined differential-mode gain ADM; and a voltage output Vout, satisfying the relationship given in the equation below. It

differs from an operational amplifier (op-amp), which ideally has infinite open-loop gain and must be used in conjunction with external elements to define the closed-loop transfer function. At one time built in discrete or hybrid form using operational amplifier and resistor networks, instrumentation amplifiers are readily available as inexpensive monolithic integrated circuits. Typical commercial amplifiers provide present gains of 1, 10, 100, and 1000. In some cases, the gain may be set to a special value by one or more external resistors. The frequency response invariably is flat, extending from 0 (dc) to an upper frequency of about 1 kHz to 1 MHz. See Integrated circuits, Operational amplifier

Instrumentation amplifiers are used to interface low-level devices, such as strain gages, pressure transducers, and Hall-effect magnetic sensors, into a subsequent high-level process, such as analog-to-digital conversion. See Amplifier, Differential amplifier, Pressure transducer, Strain gage

McGraw-Hill Concise Encyclopedia of Engineering. © 2002 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
illustrated an implementation of a current-balancing instrumentation amplifier with a single differential stage [28].
Figure 12 shows the application of the proposed CCII to implement instrumentation amplifier of [9].
The output voltage of the instrumentation amplifier [V.sub.OUT] passing through the LP filter is given by
Instrumentation amplifier is one of the most frequently used design blocks in analogue signal processing which is used for differential signal amplification [1,2].
They are very cheap and can be a good precision instrumentation amplifier. The AD620 is a very effective preamplifier because of its low input voltage noise of 9 NV/[square root]Hz at 1 kHz, 0.28 vs.
van Roermund, "A 300[degrees]C dynamic-feedback instrumentation amplifier," IEEE Journal of Solid-State Circuits, vol.
The USBDR-8 from Alligator Technologies is a USB distribution and power rack for the company's family of USBPxx-S1 single channel programmable signal conditioning instrumentation amplifier and filters.
The AD623 is an integrated single-supply instrumentation amplifier that delivers rail-to-rail output swing and low power consumption (1.5 mW at 3 V).
Conversely, DAQ cards normally feature several, more closely spaced hardware and software gain selections, and are sometimes further classified as "low gain" or "high gain." The difference has to do with the amount of gain applied to the input signal by the card's instrumentation amplifier before the signal is digitized.
HP also has introduced an instrumentation amplifier with internal leveling that uses a wideband, continuously variable attenuator.
"A 2.2 [micro]W 94 nV/[square root]Hz, chopper-stabilized instrumentation amplifier for EEG detection in chronic implants," in IEEE Int.

Full browser ?