A Stereo Multi-Rate Audio Front-End Suitable for Mobile Multimedia Applications

Abstract

A flexible, high quality audio front-end integrated circuit with low power consumption is presented. Targeted for the world-wide (GSM) mobile communication system, it is capable of stereo and mono reception and transmission, supports narrow voice-band as well as wide voice-band modes, FM radio and MP3 stereo play-back. The front-end provides a low-noise bias voltage for microphones as well as hands-free buffers driving 8 loads in bridge tied load configuration and two earphone outputs for stereo. The front-end is highly area-efficient, occupying 1.92 mm 2 in a 0.25-µm CMOS technology. Measured results show a maximum power consumption of 11.8 mW at 2.65 V analog and 1.65 V digital supply.