Reconfigurable audio output stage in 45nm process for single speaker mobile application

This paper presents a fully integrated solution for single speaker mobile application which can be embedded in today´ market codecs. It makes use of a capacitor-free low-dropout regulator (LDO) which shares the pass device with the output audio power stage, allowing high quality performances for both hands-free and receiver modes and high power for hands-free. The system is capable of delivering 1 W in hands-free operation, and 80 mW in receive with 118 dB of PSRR and 0.06% of THD. The whole design has been implemented using TSMC 45 nm technology.