IEEE Trans Biomed Circuits Syst. 2011 Jun;5(3):201-13. doi: 10.1109/TBCAS.2010.2079329.
A dual-channel directional digital hearing aid front end using microelectromechanical-systems microphones, and an adaptive-power analog processing signal chain are presented. The analog front end consists of a double differential amplifier-based capacitance-to-voltage conversion circuit, 40-dB variable gain amplifier (VGA) and a power-scalable continuous time sigma delta analog-to-digital converter (ADC), with 68-dB signal-to-noise ratio dissipating 67 μ W from a 1.2-V supply. The MEMS microphones are fabricated using a standard surface micromachining technology. The VGA and power-scalable ADC are fabricated on a 0.25-μ m complementary metal-oxide semciconductor TSMC process.
本文提出了一种采用微机电系统（MEMS）麦克风的双通道定向数字助听器前端和自适应功率模拟处理信号链。模拟前端由基于双差分放大器的电容-电压转换电路、40dB 可变增益放大器（VGA）和可扩展功率的连续时间 sigma-delta 模数转换器（ADC）组成，在 1.2V 电源下消耗 67μW 即可实现 68dB 的信号噪声比。MEMS 麦克风采用标准的表面微机械加工技术制造。VGA 和可扩展功率 ADC 采用 0.25μm 互补金属氧化物半导体 TSMC 工艺制造。
