An integrated 3-level fully adjustable PWM class-D audio amplifier in 0.35um CMOS

In English A Class-D audio amplifier utilizing a fully adjustable 3-level Pulse Width Modulation (PWM) is presented. The amplifier is fully integrated in a 0.35um CMOS process, and is powered by a 3.3V power supply. The system includes an internal fully adjustable triangle-wave oscillator, which is used to generate the PWM carrier. Delivering an output power of 300mW is a differential bridge (7.5cm pMOS, 3cm nMOS), driving a 16¿ load. The THD+N of the system is less than 0.2%, and the efficiency at 300mW is 89%.