Power solutions for Class-D audio amplifiers

Today, the most popular medium and high power audio amplifiers employ a Class-D working scheme due to high efficiency and excellent linearity. Compared to traditional analog amplifiers, Class-D uses high frequency pulse width modulation, similar to a switch mode power supply. Even though Class-D amplifiers incorporate negative feedback on supply voltage, the reality is that the output impedance of the power supply has an impact on audio quality. This topic describes how to properly design a power supply for a high power Class-D amplifier based on the output impedance requirements as well as on typical requirements like average and peak power demands. Two different built and tested power reference designs are introduced. The first is for a universal AC/DC input suitable for home theater, monitor and soundbar applications. The second solution covers high power automotive applications rated to several hundred watts.

Why should I take this training?

• Class D amplifiers are becoming more common, due to their performance improvements over Class A and Class AB
• The design of a Class D amplifier power supply can heavily impact the overall performance of the end system

What will I learn?

• A review of basic audio amplifier topologies
• Important considerations for an audio power supply
• Causes of audio quality degradation due to power supplies
• Performance of built and tested design