By Janet Heath
Instrumentation amplifiers (INAs) are precision devices, but they have a particular function and aren’t another type of operational amplifier (op amp). Instrumentation amplifiers are not op amps; you can’t configure them in a multitude of ways, and you only set gain to a chosen value, and only within a specified range. So op amps are much more versatile than instrumentation amplifiers. An INA should never be called an “op amp,” because they aren’t and do not have the application flexibility that op amps have. INAs are precision amplifiers with a closed-loop gain over a set range.
Precision amplifiers are op amps that have better specifications and are more accurate than your average op amp. Precision amplifiers can have better specs with precision offset, zero-drift over time, lower internal noise (nV/√Hz), and input bias current. Precision op amps have precisely matching resistors etched in the substrate at the chip level. Precision op amps are necessarily integrated chips so that the components are precisely matched.
INAs do not have an external feedback. Op amps have external feedback loops that can be set by the user. INAs have excellent common-mode rejection ratios (CMRR). CMRR is a measure of the amplifier’s ability to reject signals that are common to both inputs. In this way, INAs are often used for... Read more on Analog IC Tips
Instrumentation amplifiers (INAs) are precision devices, but they have a particular function and aren’t another type of operational amplifier (op amp). Instrumentation amplifiers are not op amps; you can’t configure them in a multitude of ways, and you only set gain to a chosen value, and only within a specified range. So op amps are much more versatile than instrumentation amplifiers. An INA should never be called an “op amp,” because they aren’t and do not have the application flexibility that op amps have. INAs are precision amplifiers with a closed-loop gain over a set range.
Precision amplifiers are op amps that have better specifications and are more accurate than your average op amp. Precision amplifiers can have better specs with precision offset, zero-drift over time, lower internal noise (nV/√Hz), and input bias current. Precision op amps have precisely matching resistors etched in the substrate at the chip level. Precision op amps are necessarily integrated chips so that the components are precisely matched.
INAs do not have an external feedback. Op amps have external feedback loops that can be set by the user. INAs have excellent common-mode rejection ratios (CMRR). CMRR is a measure of the amplifier’s ability to reject signals that are common to both inputs. In this way, INAs are often used for... Read more on Analog IC Tips
