可调频率跨导电容Chebyshev滤波器的设计及仿真  

Design and simulation of a tunable frequency OTA -C Chebyshev filter

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,湖南长沙410082

出　　处：《通信学报》2006年第6期81-86,共6页Journal on Communications

基　　金：中国博士后科学基金资助项目;高校博士点基金资助项目~~

摘　　要：首先提出了一种新的跨导运放,其输入级采用了工作在线性区的MOS管作源极负反馈有源电阻实现其良好的线性度,输出级采用折叠式结构,并在电路中引入电压共模负反馈(CMFB)稳定其静态工作点。接着提出了一种新的利用开关电容技术调节跨导运放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,应用这些电路设计得到了四阶Chebyshev低通滤波器,并实现其频率的精确可调,0.35μm2层多晶硅,4层金属CMOS工艺Spicemodel仿真结果表明设计正确、有效。A new transconductor operational amplifier（OTA） using active resistor of source degeneration was presented. The method was developed through acting differential pair degenerated by two MOSFET operating in the triode region as active resistor in its input stage, the circuit was designed in working in stable quiescent operating point with folded cas- cade output stage using voltage common-mode feedback（CMFB） circuit. As an tunable cutoff frequency fourth order Chebyshev lowpass filter, an accurately tunable Gm of OTA was used, which employed switching capacitor technique to tune Gm value. Simulated results show that the practical frequency response of the filter is very near to that of idealized prototype by applying 2-poly 4-metal 3.3V power supply 0.35μm CMOS technology spice model.

关 键 词：跨导运放 源级负反馈 电压共模负反馈 跨导电容滤波器 Chebyshev滤波器 

分 类 号：TN413[电子电信—微电子学与固体电子学]