A compensation technique for reduction of performance errors of operational amplifiers

A simple compensation technique, previously employed for the improvement of the sweep linearity of bootstrap sweep generators, is investigated as a means of reducing the performance errors of operational amplifiers. It is shown that such compensation is capable of quite general application but is of most value in the case of transistor amplifier circuits, where the active element may be regarded as a current amplifier. Thus multiple-input transistor operational amplifiers may be improved by compensation, whereas in the valve amplifier case the technique is restricted to single-input circuits. Simple forms of compensating circuit are derived for summing, integrating and differentiating amplifiers; correction for the fall of gain of the active element at high frequencies is also included. The main results of the paper are illustrated by practical examples in which the active element is a single common-emitter stage.