基于运放开环频率特性的放大器幅频特性分析  

Analysis of amplifier's frequency-amplitude characteristic based on the operational amplifier's open loop frequency response

作　　者：张丽敏[1] 陈孝桢[1] 陈娟[1] 高琴[1] 

机构地区：[1]南京大学电子科学与工程系,南京210093

出　　处：《电子测量技术》2009年第6期37-39,共3页Electronic Measurement Technology

摘　　要：在实验测试中发现同相放大器的幅频特性在通频带内略有峰值出现。本文基于运放二阶模型论述了同相放大器幅频特性出现峰值的原因,进而讨论了反馈系数对其幅频特性的影响。通过仿真分析同相放大器幅频特性,指出电路设计时反馈系数在允许的范围内应尽量小,以减少运放的二阶特性对放大器的影响,这对运用运放设计放大电路有很好的指导作用。In the experiment, it is found that the noninverting amplifier＇s frequency-amplitude has peak value in its transmission band. Based on the second order model of the operational amplifier, the paper elaborates the reason for peak value and discusses the influence of the feedback coefficient on the frequency-amplitude characteristic. By simulating the amplifier＇s frequency-amplitude characteristic, the paper points out that the feedback coefficient should be as small as possible in order to reduce the influence of the operational amplifier＇s second order characteristic on the amplifier, and this has a good instruction to design amplifying circuit.

关 键 词：运放 二阶模型 幅频特性 反馈系数 

分 类 号：TN72[电子电信—电路与系统]