A CMOS MEMS Audio Transducer Implemented by Silicon Condenser Microphone With Analog Front-End Circuits of Audio Codec

Abstract

This study proposes a CMOS MEMS audio transducer implemented by combining a silicon condenser microphone with analog front-end audio codec circuits. The proposed CMOS MEMS audio transducer is attractive because the sensor and all the circuits are robustly and compactly integrated. The overall size of the proposed device is much smaller than traditional electrets-condenser microphones (ECMs). Another innovation of the proposed CMOS MEMS audio transducer is that it can operate without any charge pump circuits, which overcomes the problem of requiring a high bias voltage. Measurement results confirm the correct functions and performance of the proposed CMOS MEMS audio transducer. The area of the proposed CMOS MEMS audio transducer is 1352 x 1410 mu m(2) and the FOM of the proposed sigma-delta modulator is 148 dB. The proposed CMOS MEMS audio transducer is suitable for audio devices, such as audio codecs.