高速差分探头在应用中的设计与研究  

The Design and Research of High-speed Differential Probe in the application

作　　者：杨晓杰[1] 王俊力[1] 张诗羽 黄继业[1] 

机构地区：[1]杭州电子科技大学电子信息学院,浙江杭州310018

出　　处：《现代电子技术》2015年第16期115-117,共3页Modern Electronics Technique

摘　　要：分析了对带宽要求较高的全差分放大器LMH6551MA和3个高速运放LMH6703组合而成的差分探头电路，由于LMH6551MA是一款带宽较大的电压反馈型放大器，所以可用于差分信号源的组成。3个LMH6703构成电压增益可由外部电阻自由控制在1～10之间的仪表放大器。最后再通过一个基于LMH6703的二阶低通滤波器在20MHz频率范围内得到一个失真较小的原始信号。差分信号源中单端转双端放大器的设计要进行阻抗匹配，而仪表放大器在得到电路放大倍数的同时能有效抑制共模信号。The system is based on LMH6551MA, a fully differential amplifier of high bandwidth requirements, and differential probe circuit, a combination of three high-speed operational amplifier LMH6703.Since LMH6551MA is a type of voltage feedback amplifier with high bandwidth, so it can be used for the differential signal source. Three LMH6703 can constitute the instrumentation amplifier that the voltage gain can be controlled by external resistance from 1 - 10. Finally, through a second-or- der low-pass filter based on LMI-I6703 can get a less distortion of the original signal in 20 M frequency range. The design for sin- gle-ended to dual amplifier in differential signal source should do the impedance matching, and the instrumentation amplifier can get circuit magnification, in the meantime, the instrumentation amplifier can effectively suppress the common mode signal.

关 键 词：仪表放大器 LMH6551MA LMH6703 差分探头 

分 类 号：TN722.75[电子电信—电路与系统]