一种低功耗线性范围宽的跨导放大器及其在滤波器中的应用  

A low power highly linear CMOS OTA and its application in OTA-C filter

作　　者：郭小蓉[1] 李安[1] 王春华[1] 孙晶茹[1] 何海珍[1] 李志斌[2] 

机构地区：[1]湖南大学信息科学与工程学院湖南大学先进通信技术湖南省高校重点实验室,湖南长沙410082 [2]湘潭大学能源工程学院,湖南湘潭411100

出　　处：《电路与系统学报》2013年第2期472-477,共6页Journal of Circuits and Systems

基　　金：国家自然科学基金(61274020);湖南省高校重点实验室开放基金(No.12K011)资助项目

摘　　要：本文分析了以往文献中提出的各类跨导放大器(OTA,operational transconductor amplifier)的结构特点,为了能更好地改善线性度并降低功耗,本文提出了一种全差分带电流负反馈的跨导放大器。在1.5V的电源电压下,经cadence仿真平台验证,该跨导放大器的线性范围拓宽到1V,IIP3达到24.80dBm,功耗低于14μW。将此跨导放大器应用到三阶椭圆低通跨导电容(OTA-C)滤波器中,经cadence仿真验证,该滤波器的幅频特性陡峭,IIP3达到13.51dBm,功耗为1.6mW。The characteristics of every published operational transconductance（OTA） are analyzed.In order to improve linearity and reduce power consumption,a fully-differential CMOS operational transconductance amplifier（OTA） with negative current feedback is presented in this brief.The source degeneration topology in previous researches is modified to achieve higher linearity in the proposed circuit.Simulation results show that the IIP3 is 24.80dBm and the input voltage swing is up to 1V under 1.5V power supply.The power consumption of the proposed OTA is less than 14μW.A third-order low-pass Gm-C filter implemented with the presented OTA is verified.Simulation indicates that the filter could operate well at the required speed and the IIP3 is 13.51dBm.The power consumption of the filter is 1.6mW.

关 键 词：跨导放大器 椭圆滤波器 线性度 电流负反馈 

分 类 号：TN722.7[电子电信—电路与系统]