一种新的CMOS MOCCII的高频补偿方法  

A novel method of CMOS MOCCII's HF compensation

作　　者：胡明祥[1] 王春华[1] 

机构地区：[1]湖南大学计算机与通信学院,湖南长沙410082

出　　处：《电路与系统学报》2009年第6期121-125,共5页Journal of Circuits and Systems

基　　金：湖南省自然科学基金(04JJ3039);国家自然科学基金资助项目

摘　　要：本文提出了一种简单而有效的具有高频补偿的CMOS MOCCII电路。对于电压传输函数VX/VY,采用源极电容耦合放大器的方式实现高频补偿;对于电流传输函数Iz/Ix、Iz-/Ix,采用在电流镜中加一个可调电阻方法,使得电流镜的传输函数由一阶系统变成可调极点的二阶系统,调节电阻大小,使得极点远离S平面原点,从而提高电流镜频带宽度。仿真表明,VX/VY的转折频率由补偿前的92.690MHz提高到补偿后的184.127MHz;Iz/Ix及Iz-/Ix的转折频率分别由补偿前的66.708MHz、58.780MHz提高到补偿后的272.965MHz和279.042MHz,而-3dB截止频率分别达到871.936MHz和814.185MHz。最后,从应用方面给出了由补偿前后MOCCII所构成的电流模式滤波器。The paper presents a simple and effective CMOS MOCCII circuit with HF compensation. For voltage transfer function VX/VY, source capacitively coupled amplifier is introduced to achieve HF compensation. For current transfer function Iz/Ix and Iz-/Ix, adding a tunable resistor in current mirrors is adopted, which makes the first order system of current transfer function of the current mirrors become second order system with adjustable poles. Controlling the resistance, lets the poles keep away from the origin in the plane S, consequently improves the bandwidth of the current mirrors. The simulation results show that the corner frequency of VX/VY has been improved from 92.690MHz before compensation to 184.127MHz after compensation, and the corner frequency of Iz/Ix and Iz-/Ix has separately been improved from 66.708MHz and 58.780MHz before compensation to 272.965MHz and 279.042MHz after compensation, and the -3dB cut-off frequency reach separately 871.936MHz and 814.185MHz. Finally current mode filters composed of MOCCII before and after compensation are presented.

关 键 词：MOCCII 滤波器 电流镜 高频补偿 

分 类 号：TN713[电子电信—电路与系统]