电流模精密整流电路

由电压型运算放大器组成的精密整流电路要严格地匹配电阻才能获得精密全波整流波形．本文给出一种具有CCⅡ电路特性由运算放大器AD844所构成的电流模精密整流电路．无需匹配电阻就可输出良好的精密全波整流波形．且具有输入电压范围大，频带宽等特点．     

Novel low-voltage low-power high-precision CCII± based on bulk-driven folded cascode OTA

This paper presents possible approaches to the design of a novel low-voltage, low-power, and high-precision current conveyor of the second generation (CCII±) based on the bulk-driven folded cascode operational transconductance amplifier (OTA) with extended input common-mode voltage range. This CCII± utilizes bulk-driven differential pairs to obtain a nearly rail-to-rail input stage at a low supply voltage. The proposed conveyor operates at a low supply voltage of ±400 mV with a reduced power consumption of only 64 μW. A current-mode multifunction filter is presented as an application of the CCII±. This filter provides five transfer functions simultaneously, namely low-pass, band-pass, high-pass, notch, and all-pass. The filter has the following properties and advantages: it employs three bulk-driven current conveyors BD-CCII±, three grounded resistors, and two grounded capacitors, which is suitable for integrated circuit implementation. Furthermore, the input signal is connected to the low-impedance X terminal of the BD-CCII± whereas the output signals are taken from the high-impedance output terminals Z+ and Z−. Finally, the pole frequency and quality factor of the designed filter are tunable independent of each other. PSpice simulation results using the 0.18 μm CMOS technology are included to prove the results.     

Systematic Generation of Current-Mode Linear Transformation Filters Based on Multiple Output CCIIs

A transformation called current-mode linear transformation (CMLT) and its filter applications using multiple output second-generation current conveyors (MOCCIIs) are presented. The systematic method is developed to realize CMLT MOCCII-based filters efficiently. Based on the proposed design tables, we can synthesize high-order current-mode all-pole and elliptic filters with MOCCIIs, grounded resistors and capacitors. Moreover, the high-frequency elliptic filter can also be efficiently realized by adding capacitors to the relative all-pole filter, although floating capacitors are needed. Third-order Chebychev and elliptic lowpass filters are described in this paper. Experimental results that confirm the theoretical analysis are obtained. Furthermore, the proposed circuits can be extended to higher-order filters.     

线性变换有源CC滤波器的实现

本文研究了应用第二代电流传送器（ＣＣＩＩ＋）实现线性变换（ＬＴ）有源滤波器，基于线性变换，给出了实现电流传送器（ＣＣＩＩ＋）滤波器的两个系统设计简表。应用此设计简表能方便地综合设计全极点与椭圆点滤波器。作为例子，文中实现了一个新的三阶椭圆低通滤波器，模拟仿真结果与理论分析吻合。     

通用有源电流模式滤波器

提出了两种通用有源电流模式滤波器：１．用两个电流传送器（ＣＣＩＩ）实现的电流模式三介滤波器新电路,选择不同的输入信号组合即能获得低通、高通、带通、陷波和全通五种二阶滤波函数;２．由ＣＣＩＩ和多输出地运算放大器（ＯＴＡ）实现的单输入多输出滤波器新电路、所提电路结构简单、中心频率ω０和品质因数Ｑ独立可调、无源元件人武部接地,滤波器特性参数对的元件灵敏度低,理论分析和计算机仿真表明所提电路方案正确。     

镜像元件及其应用

阐述了镜像元件的特性,包括零器-镜像元件连接的等效性;提出了镜像元件进而病态元件的级联特性,同时引入镜像元件完善了CCII族;对现代电网络分析中考虑镜像元件的方法进行了总结.镜像元件能够灵活地表示有源器件和等价电路,常在复杂的电路设计与分析中提供灵活和简洁的方法,其作为基础的病态元件应用越来越广泛.     

A new simulation of mutually coupled circuit based on CCIIs

In this paper, a new circuit for simulating a mutually coupled circuit is presented. The circuit employs four second-generation current conveyors (CCIIs) as active elements, together with five resistors and two grounded capacitors as passive elements. The values of a primary self-inductance, a secondary self-inductance and a mutual inductance can be chosen arbitrarily. As an application, a double-tuned circuit is simulated using the proposed circuit to confirm its validity.     

CMOS MOCCII高频非理想特性研究

本文用高频小信号等效电路对MOCCII电路进行了分析,提出了vx/vy的双二次模型理论.采用最小二乘法中的最速下降法根据MOCCII的PSPICE仿真曲线对该模型进行最小二乘曲线拟合,得出双二次模型各参数.拟合后曲线与PSPICE仿真曲线在取样点误差的方均根值为10-7数量级:同时对Iz/Ix的单极点模型和Iz-/Ix的双极点模型均进行了最小二乘曲线拟合,得出了模型参数,拟合后曲线与PSPICE仿真曲线在取样点误差的方均根根值为10-5数量级.这些MOCCII(CCII)高频模型在高频滤波器等电路的设计中具有重要的意义.     

基于MOCCII多功能二阶电流模式滤波器设计

文中提出了一种基于M OCC II(多端输出第二代电流传输器)的单输入三输出二阶滤波器电路模型,由该模型可得出几种不同的滤波器电路,每种滤波器电路都由四个M OCC II、两个接地电容和电阻组成。不但能同时实现二阶高通滤波、低通滤波和带通滤波功能,还可以通过对输出端的直接组合,实现带阻和全通滤波功能及其他任意形式的二阶信号传输功能。滤波器的角频率和品质因数独立可调,应用非常灵活。与同类滤波电路相比较,该电路不但结构简单,而且使用灵活,有利于集成。同时,对其中一种滤波器的滤波特性进行了测试,实验结果表明,滤波器的滤波性能良好,电路模型完全正确。     

An intelligent technique for generating equivalent gyrator circuits using Genetic Algorithm

Genetic algorithm (GA) applications in analog design circuits play an important role with promising results. This algorithm is utilized to generate equivalent circuits for the well-known gyrator circuit which is the most commonly used active circuit for the realization of a grounded inductor. The conventional gyrator circuit is realized by the op-amp which has the drawback of frequency limitations. This paper introduces the gyrator-GA Technique. It is an intelligent technique for generating equivalent gyrator circuits utilizing Second Generation Current Conveyor (CCII) as well as Transconductance Amplifier (TA) circuits. The proposed algorithm is based on the pathological representation of the active blocks. As illustrations to demonstrate the systematic realization of gyrator-GA, a fifth-order Butterworth lowpass filter is designed and simulated using PSPICE.