On the design and efficiency of class A, B, AB, G, and H audio power amplifier output stages

A procedure for analyzing, designing, and assessing audio power amplifier output stages operating in classes A, B, AB, G, and H with reactive loads is presented. The study considers steady-state sinusoidal analysis for BJT, IGBT, and MOSFET technologies. Electricalmechanical-acoustical models of loudspeakers and enclosures are used whose parameters are obtained through the Thiele-Small model. An equivalent electrical-thermal model for a transistor-heatsink-ambience system associated with instantaneous and average powers is used for designing the power stage. A MATLAB software has been developed, which provides considerable support to the designer for all phases required in the design of audio power amplifier output stages.