A Designer's Guide: Monolithic Instrumentation Amplifiers

Monolithic IC instrumentation amplifiers were developed to satisfy the demand for in-amps that would be easier to apply. These circuits incorporate variations in the 3-op amp and 2-op amp in-amp circuits previously described, while providing laser-trimmed resistors and other benefits of monolithic IC technology. Since both active and passive components are now within the same die, they can be closely matched—this will ensure that the device provides a high CMR. In addition, these components will stay matched over temperature, ensuring excellent performance over a wide temperature range. IC technologies such as laser wafer trimming allow monolithic integrated circuits to be tuned up to very high accuracy and provide low cost, high volume manufacturing. An additional advantage of monolithic devices is that they are available in very small, very low cost SOIC, MSOP, or LFCSP (chip scale) packages designed for use in high volume production.