Design and implementation of the integration applications for a portable MP3 player with a Bluetooth hand-free/set

Considering the demand for a wireless connection to a portable MP3 player, we propose an integration design of a MP3 player with a Bluetooth hand-free/set. The Bluetooth module serves as the wireless channels between the MP3 player and the wireless headphone, the wireless microphone and recording memory cards, the FM receiver, and the cellular phone. Audio switches in our design are used to facilitate the corresponding audio paths. We have chosen a highly integrated chip set to fulfill the required functions, resulting in less power consumption, and in an extension of the recharge cycle, in this integration design, we use a simple operational amplifier with a negative feedback circuit to suppress the common mode noise resulting from high frequency signal coupling between the audio paths. Overall, our prototype design has already demonstrated good sound quality for a wireless MP3 player.