截止频率精确可调跨导电容滤波器实现  

Realization of Gm-C Filter with Accurate Tunable Frequency

作　　者：江金光[1] 王耀南[1] 

机构地区：[1]湖南大学电气与信息工程学院,长沙410082

出　　处：《电子与信息学报》2006年第7期1335-1339,共5页Journal of Electronics & Information Technology

基　　金：中国博士后科学基金;国家自然科学基金(60375001);高校博士点基金资助课题

摘　　要：提出了一种新的利用开关电容技术调节偏置电流值大小的电路,应用该电路可以精确调节跨导运放Gm值的大小。采用既具有电压共模负反馈(CMFB)电路,又同时具有工作在线性区的MOS管作源极反馈有源电阻,实现其良好线性度的跨导运放。设计了三阶椭圆函数低通滤波器,并实现其频率的精确可调。应用台积电(TSMC)2层多晶硅,4层金属(2P4M),3.3V电源电压,0.35μmCMOS工艺Spicemodel仿真得到的频响曲线与理想情况十分接近。This paper presents a new circuit to tune Gm value of transconductor accurately which employs switched-capacitor technique to change the bias current of transconductor. A third order elliptical function lowpass filter with accurate tunable frequency is designed using transconductor that is not only with voltage common-mode negative feedback, but also with varying bias-triode transistors to improve the linearity of this circuit. Simulated results show that the practical frequency response of the filter is very near to that of idealized circumstance by applying TSMC 2-poly 4-metal 3.3V power supply 0.35 μm CMOS technology Spice model.

关 键 词：电压共模负反馈 频率可调 跨导电容滤波器 源极反馈有源电阻 椭圆函数滤波器 

分 类 号：TN713[电子电信—电路与系统] TN432