Single stage switching audio power amplifier and power supply

In recent years, the introduction of audio switching amplifiers in the audio chain has improved the efficiency, size, and weight of several apparatus. The integration between power supply and amplifier systems appears as the next logical step to achieve further reducing in size, cost and energy consumption. The present paper presents one single stage switching power amplifier and power supply for sub-woofer amplification. It corresponds to a symbiotic choice of a three-level modulation switched audio amplifier with differential filter, feed forward control and a valley-fill circuit. It has high efficiency; very low power supply capacitor values, and minimizes the weight, size, complexity and cost of the reproduction system. The realization of a prototype shows the effectiveness of the proposed solution.