This paper addresses the realization of high-performance, high-efficiency audio amplifiers using pulse-width modulation and double-loop feedback techniques. Using both current and voltage feedback, certain advantages are realized in comparison to more conventional topologies. Both two-level (bipolar) and three-level (unipolar) PWMs are investigated in detail, in combination with the novel feedback topology, to find the optimal modulation method. A 200-W/8-ohm prototype has shown a very convincing performance with THD+N.
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