Headphone Amp Design: Quality Vs. Efficiency

摘要

In recent years, Class D amplifiers have made inroads into audio consumer electronics, automotive, and portable audio world with the allure of a smaller implementation area and higher efficiency. This efficiency has helped scale automotive amplifiers and portable media docking stations to have more power in a smaller form factor, driving a whole new set of consumer audio devices. However, there is a specter that follows this new technology. As in all engineering discussions, there is a tradeoff for this increased efficiency and smaller form factor. Increased distortion (a.k.a. noise) and electromagnetic interference (EMI) are the hurdles that must be overcome in the pursuit of the 90% to 95% efficiency that Class D amplifiers can offer.