Instrumentation amplifiers: A comparative study on behalf of monolithic integration

摘要

An investigation has been made into the possibility of fully integrating an instrumentation amplifier in monolithic form. The small dimensions and the low price of an IC-version allow more frequent application of the instrumentation amplifier in electronic instrumentation systems. This application can raise the accuracy and lower the sensitivity for common-mode interference signals. Of the many types of instrumentation amplifiers, the one with voltage-to-current conversion appears to be most suitable for monolithic integration. For a low price per unit the number of components external to the IC must be low. A circuit configuration which requires only two external resistors to fix the amplification factor accurately is the differential-difference amplifier (DDA). This configuration possesses some particularly useful applications.