Instrumentation amplifiers: A comparative study on behalf of monolithic integration

An investigation is made into the possibility of fully integrating an instrumentation amplifier in monolithic form. Of 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.