On the operation of cascode gain stages

The gain-enhancing action of the cascode is explained on the basis of a gain developing at an intermediate node. In this sense, a cascode with a high-impedance load acts as the cascade of an inverting and a noninverting stage, with the total gain determined by the product of the intrinsic gains of each. The cascode nevertheless retains the advantage of a significantly smaller loading, which it presents at its input terminal, compared to a common-source stage. This analysis approach is extended to other circuits configured for intrinsic gain subject to constraints imposed by current sources, where gain enhancement is obtained