Desenvolvimento de um amplificador de áudio de alto desempenho utilizando realimentação negativa global

Abstract

This paper proposes the development of a high-performance audio amplifier with global feedback. The proposed topology is based on "A design methodology for audio amplifiers with no global negative feedback: proposal and validation" Visintin et al. (2022) in order to compare the approaches of amplifiers with and without global negative feedback. A 50W power amplifier is designed and built. In this project example, three stages are used with field effect transistors operating with a symmetrical voltage of ±55V. The practical results obtained satisfied the design requirements, such as: Slew Rate above 1.13V/us (4.2V/us), upper cutoff frequency above 40kHz (250kHz), THD+N below 0, 5% (0.0296%). In this way, it was possible to develop an amplifier with global negative feedback and the objective of this work was achieved.