Class D Switching Power Amplifiers: Theory, Design, and Performance

Switching, or class D, amplifiers represent a source of untapped potential for efficient, high power amplification. They are mostly suited for mobile and portable applications. In an effort to better understand these amplifiers, this project examines the theory, design, and performance of these circuits. As a result, it was determined that Class D amplifiers are not as difficult to design and build as commonly believed. The output sound quality of a well-designed class D audio amplifier is comparable to many high fidelity conventional sound systems. D class amps typically have 90-95% efficiency at rated power compared to conventional audio amps, which have 65-70% efficiency ratings. Most importantly, these benefits are available in a smaller, more cost-effective package due to the switching amplifier’s high efficiency and capability for integration.