Analog signal processing for a class D audio amplifier in 65 nm CMOS technology

Class D audio amplifiers provide high quality audio signals with very good efficiency. This makes them not only useful for high power home audio equipment and television, but also for battery powered portable devices. This paper shows details of an analog signal processor for a class D output stage which provides the audio output for a hands-free amplifier in mobile telephones. Two differential stages including output drivers have been successfully implemented on a combined baseband and audio chip using the thick oxide option of a 65 nm (gate width) CMOS process.