The AD521 is a second generation, low cost, monolithic IC instrUmentation amplifier developed by Analog Devices.As a trUe instrUmentation amplifier, the AD521 is a gain block with differential inputs and an accurately programmable input/output gain relationship.
The AD521 IC instrUmentation amplifier should not be confused with an operational amplifier, although several manufactUrers(including Analog Devices)offer op amps which can be used as building blocks in variable gain instrumentation amplifier circuits. Op amps are general-purpose components which, when used with precision-matched external resistors, can perform the instrUmentation amplifier function.
An instrumentation amplifier is a precision differential voltage gain device optimized for operation in a real world environment, and is intended to be used wherever acquisition of a useful signal is difficult. It is characterized by high input impedance, balanced differential inputs, low bias currents and high CMR.
