實現耳蝸之次臨界互補式金氧半電路

Abstract

於本論文中, 我們以類比積體電路完成人類聽覺器官耳蝸之頻率響應模擬 o 耳蝸電路含有濾波器組, 自動增益調節電路, 內耳半波整流器及螺旋體 之脈衝產生器等, 電路中之金氧半電晶體元件主要操作在次臨界電流區, 以達到省電功能及配合耳蝸特性o 人耳中之外毛細胞提供了增益調節功 能, 此項功能使耳蝸可以將變化極大的聲音訊號, , 轉成可接收範圍內的 訊號, 促使人類耳朵可接收更寬範圍的輸入訊號o 傳統之濾波器組, 很難 藉由濾波器特性的改變而得到增益調節功能o 我們設計一個改良的運算電 導放大器, 它可作為增益控制器o 藉此運算電導放大器的加入, 我們的耳 蝸電路可具有更強的功能o The thesis presents an analog integrated circuit that implements an auditory neural representation of spectral shape in the cochlea. The cochlea circuit contains the filter bank, auto gain control, inner hair cell and spiral gangling cell, which is derived from neural physiological studies. In this circuit, the MOS FET devices are primarily operating in the subthreshold current regime. Gain control function for a wide range of input signal, supported by outer hair cell, is an important feature to the cochlea model. Traditionally it is hard to change the gain of filters in the cochlea model through varying bias current in the operational transconductance amplifier. We have proposed a modified operational transconductance amplifier circuit that can automatically create the gain control function in our cochlea model efficiently.