ABSTRACT
Amplifi er Architectures This grandiose title simply refers to the large-scale structure of the amplifi er; that is, the block diagram of the circuit one level below that representing it as a single white block labeled Power Amplifi er. Almost all solid-state amplifi ers have a three-stage architecture as described below, though they vary in the detail of each stage. Two-stage architectures have occasionally been used, but their distortion performance is not very satisfactory. Four-stage architectures have been used in signifi cant numbers, but they are still much rarer than three-stage designs, and usually involve relatively complex compensation schemes to deal with the fact that there is an extra stage to add phase shift and potentially imperil high-frequency stability.
