Next Generation Class-D Audio Amplifiers (NGCDA)

Class-D Audio amplifiers are used in various audio systems in cellphones, cars, home stereo audio systems, hearing aids, automobiles, etc. Two topics are developed under the theme of next-generation Class-D audio amplifiers.

Digital-input Class-D audio amplifiers: To improve audio quality, such systems are becoming more and more digital intensive where various algorithms can be easily applied to improve audio quality. This requires the audio amplifier to move from the conventional analog input to digital input. Various digital-input Class-D audio amplifiers can be found in literature and on market, however, the performance, especially in terms of distortion, is often not optimal. Moreover, the trade-offs among various topologies are rather vague. In this research, we will investigate and compare the existing topologies, innovate towards new topologies to overcome the performance barrier while maintaining low system costs.

Class-D audio amplifiers in GaN technology: Most audio amplifiers nowadays are made with CMOS technology. However, new technology such as GaN offers potentially much higher performance in terms of power efficiency and higher switching frequency (~10x higher compared to CMOS technology). The latter is highly beneficial to reduce system costs by allowing the use of much smaller and cheaper passive components such as inductors and capacitors. In this research, we will explore the feasibility and benefits of GaN technology for the next generation of Class-D audio amplifiers.