一种高线性度低失真跨导运算放大器的设计  

Design of a Transconductance Operational Amplifier with High Linearity and Low Distortion

作　　者：蒋思中 覃志松 JIANG Sizhong;QIN Zhisong(Intelligent Manufacturing Institute,Guangxi Vocational&Technical College,Nanning Guangxi 530226,China;School of Computer Science and Information Security,Guilin University of Electronic Technology,Guilin Guangxi 541004,China)

机构地区：[1]广西职业技术学院智能制造学院,广西南宁530226 [2]桂林电子科技大学计算机与信息安全学院,广西桂林541004

出　　处：《电子器件》2021年第4期806-811,共6页Chinese Journal of Electron Devices

基　　金：2020年度广西高校中青年教师科研基础能力提升项目(2020KY29017);2017年度广西职业教育教学改革研究项目(GXGZJG2017A008)。

摘　　要：针对线性跨导输入范围有限的问题,提出了一种具有宽线性输入范围的高线性运算跨导放大器(Operational Transconductance Amplifier,OTA),可有效应用于包括低频连续时间滤波器在内的电流模式电路。该OTA利用源极退化和辅助差分结构,通过减少失真分量来显著增加线性范围。此外,还利用该OTA实现了一种二阶全差分滤波器。采用SCL 180 nm CMOS工艺进行了设计和仿真。实验结果表明,相比于其他设计方法,该OTA和滤波器具有更宽的线性范围和更低的失真。对于频率为1 MHz信号频率、峰间输入电压600 mV的输入,该OTA的三次谐波失真分量和互调失真分量分别为-74.8 dB和-76.1 dB,线性范围为0.9 V(1%跨导变化)。对于峰间输入电压300 mV频率为10 kHz输入,该滤波器的三次谐波失真分量和互调失真分量分别为-69.75 dB和-65.2 dB。Aiming at the problem of limited input range of linear transconductance,a high linear operational transconductance amplifier(OTA)with wide linear input range is proposed,which can be effectively applied to current mode circuits including low frequency continuous time filters.This OTA uses source degradation and auxiliary differential structure to significantly increase the linear range by reducing distortion components.In addition,a second-order fully differential filter is realized by using this OTA.SCL 180 nm CMOS process is used for design and simulation.Experimental results show that the OTA and filter have wider linear range and lower distortion than other design methods.For the input with peak-to-peak input voltage of 600 mV and frequency of 1 MHz,the third harmonic distortion component and intermodulation distortion component of OTA are-74.8 dB and-76.1 dB,respectively.For the input with peak-to-peak input voltage of 300 mV and frequency of 10 kHz,the third harmonic distortion component and intermodulation distortion component of the filter are-69.75 dB and-65.2 dB,respectively.

关 键 词：运算跨导放大器 连续时间滤波器 电流模式 线性输入 低失真 

分 类 号：TN722[电子电信—电路与系统]