差分式CMOS连续时间电流模式滤波器

提出了基地电流镜电路的差分式连续时间电流模式积分器，并用此积分器构成了全差分式连续时间电流模式低通及带通滤波器，分析并模拟了所提出的积分器及滤波器的特性，结果表明所提出了电路的具有结构简单，对称性好，失真小等优点，适于全集成。     

多输出端电流模式全差分积分器实现二阶带通滤波器

提出了用多输出端电流模式全差分积分器(MCDI)实现二阶带通滤波器的方法。分析了输入级为PMOS管的MCDI及所提出的滤波器的特性，由该类型积分器所构成的滤波器，不仅具有较高的信噪比性能，而且能达到通过调节积分器的偏置电流值的大小能使得其所构成的带通滤波器的中心频率可在很宽的范围内调控的目的。应用台积电(TSMC)2层多晶硅、4层金属(2P4M)混合信号(mixed-mode signal)3．3V电源电压、0．35μ m、CMOS工艺参数仿真得到的带通滤波器的功耗仅为0．28mW左右，仿真结果表明滤波器设计正确、有效。     

偶数阶电流模椭圆滤波器的综合设计

本文提出了一种基于MOCCII的任意偶数阶电流模椭圆滤波器综合设计方法。通过对n阶(偶数)椭圆传输函数进行分析,将其分解成一系列能用无损积分器实现的表达式;并对输出电流信号进行线性组合,以实现了偶数阶的电流模式椭圆滤波器的综合。该方法实现的电路结构简单,所用有源和无源元件最少,仅由n个接地电容,(3n-1)/2个有源器件和接地电阻构成。给出了四阶高通、低通和带通椭圆形滤波器的设计实例。Pspice仿真结果表明采用该方法设计偶数阶电流模式椭圆滤波器是可行的,适用的。     

跳耦结构差分式连续时间电流模式电流镜滤波器

在差分式电流模式电流镜积分器的基础上，提出了一个跳耦结构差分式连续时间电流模式五阶切比雪夫低通滤皮器的电流镜电路和设计方案。讨论了电流模式跳耦结构滤波器的设计方法，给出了所提出的滤波器电路的设计机仿真结果。该滤波器电路继承了电流镜电路、差分式电路、跳耦结构滤波器的优点，具有适于低电太供电、消除偶次谐波、元件灵敏度低、传递函数失真小等特点。     

基于AOA的多功能二阶电流模式滤波器及仿真

以AOA电流模式多路输出积分器和AOA电流模多路输出比例电路为基础,设计了多功能二阶电流模式滤波器。该电路既可通过改变输入信号的作用点,从同一端口分别实现高通、带通和低通滤波,又可从同一端口输入信号,从不同端口同时实现高通、带通和低通滤波,真正实现了多功能滤波。计算机仿真证明该滤波器正确有效。     

一种基于OTA和MOCCII实现的n阶多功能滤波器

提出了一种基于运算跨导放大器和第二代电流传输器结合的电流模式多功能滤波器方法。该方法是将高阶通用电流模式滤波器的传递函数分解为n个无损积分器级联的形式,适当选定输入电流信号可同时实现低通、高通、带通、带阻等滤波功能,而电路内部结构及器件数目无需改变。与同类电路相比,其设计简便、结构简单、无源元件全部接地,且易于集成。同时文中还给出了滤波器的设计实例,Pspice仿真结果与理论分析相吻合,也验证了该方法的可行性。该滤波器可用于通信、电子测量与仪器仪表的信号处理中。     

一种多功能可调开关电流双二次滤波器的实现

采用改进的Class AB开关电流(SI)存储单元设计了差分结构双线性SI积分器,由此积分器和栅极接地Class AB电流乘法器作为基本模块,设计了SI双二次滤波器.电路实现了低通(LP)、带通(BP)和高通(HP)滤波器,其截止频率ωo和Q值可通过外部直流电流连续调节.仿真结果表明设计的电路具有良好的滤波和可调性能.     

电流模式高阶滤波器设计的递推方法

给出了连续时间电流模式高阶滤波器的一种实现方法，该方法根据电流转移函数的分母多项式，以递推形式，逐步确定各个积分器的时间常数。用该方法设计所用电流镜数目少。对一个六阶滤波器的计算机仿真显示，该方法适合于设计高频电流模式滤波器。     

任意电流模式滤波器的综合实现

通过对一个任意电流模式滤波器传递函数进行一连串的数学变换,使其分解为n个无损积分器和n个电流比例器,从而提出了一种适合于任意电流模式滤波器的新的分析综合设计法,并以MCCII为有源器件实现了具体的电路模型.提出的模型具有如下优点:1)可以实现任意阶(n≥2)、任意类型的电流模式滤波器;2)实现的电路结构简单,仅由(2n+1)个有源器件、(2n+1)个电阻和n个电容构成;3)所有器件均接地,便于集成;4)在实现巴特沃斯滤波器时,通过对输出信号进行不同组合可以实现高通、低通、带通、带阻及全通滤波功能.以三阶椭圆滤波器和六阶巴特沃斯滤波器的设计为例验证了该模型的正确性.     

用信流图实现n阶CCⅡ电压模式滤波器

用信流图对电压传递函数进行模拟,再由基于双输出端电流传输器（ＣＣⅡ±）的积分器、基于反相第二代电流传输器（ＣＣⅡ－）的电压加法器和基于同相第二代电流传输器（ＣＣⅡ＋）的电压放大器综合出ｎ阶电压模式ＣＣⅡ滤波器。使用该方法,可实现任意阶低通、高通、带通等类型的ＣＣⅡ滤波器。     

对数域积分电路的分析与应用

本文分析了一种对数域积分电路的特性,以及极间电容对其性能的影响.在此基础上给出了一般对数域滤波器的设计方法,以及其在宽频带的流控振荡器(ICO)和锁相环电路中的应用,并给出了模拟结果.     

用对数域电流模式积分器实现的高频集成滤波器

文本提出了全差动对数域电流模式积分器．该积分器的时间常数受参考偏流控制,其直流增益可达60dB,在高频它具有比较平坦的相频特性。用该积分器设计的二阶滤波器和1dB波纹五阶Chebyshev低通滤波器,计算机仿真显示,“实际”频响特性几乎是理想的．且频率可在很宽的范围内调控．这种滤波器具有很低的THD。     

Micropower log-domain active inductor

An alternative implementation for emulating an active inductor is proposed. Based on a classical gyrator active inductor architecture, the new active inductor is implemented by using a log-domain current integrator instead of a voltage integrator. Inductance and Q-factor can be tuned independently Simulation results confirming the idea are shown. The proposed circuit is a micropower active inductor operating in the weak inversion region of the MOSFETs     

Integrator and differentiator with time constant multiplicationusing current feedback amplifier

A set comprising an active RC integrator and differentiator with time constant multiplication is presented. The proposed integrator and the differentiator can be used for low-frequency signal processing applications. Moreover, no extremely large-valued passive components are needed. In the integrator, the unlimited multiplication of time constants is allowed. Both have been implemented using commercially available current feedback amplifiers. Experimental results demonstrate the theoretical predictions     

有源补偿电流积分器

本文针对ＣＣＩＩ提出了一种新的有源补偿电流模式积分电路，理论分析和ＳＰＩＣＥ仿真均表明此补偿可减少非理想积分器与理想积分器之间的偏差，降低滤波器的灵敏度，本文还讨论了由此积分器构成的双积分器回路。     

GaAs FET Current-Mode Integrators and Their Application to Filters

In this paper, current-mode integrators which consist of only n-channel depletion-mode FET and their application to filters are presented. Lossy integrator is simply realized with a capacitor and a grounded gate FET. Lossless integrator can be obtained by providing a lossy integrator with a positive feedback. To do this, multi-output current mirror is proposed. To reduce 2nd-order harmonic and THD of the filter, unbalanced/balanced conversion circuit is proposed. As an application example, 3rd-order leapfrog low-pass Chebyshev filter is simulated with GaAs MESFET process parameters. Simulation results show good performances.     

A novel differential high-frequency CFA integrator

A new differential integrator implemented using current feedback amplifiers (CFAs) is presented in this paper. The resulting integrator is stable and does not employ a capacitor in the negative feedback path of the CFA for its operation. Experimental results taken from AD844 CFAs authenticate the viability of the proposed integrator.     

Switched-current (SI) integrators with reduced effect of transistor mismatches

Switched-current (SI) circuits are widely used for analog sampled-data signal processing, due to their compatibility to the pure digital CMOS process. As their main building blocks are current mirrors, they suffer from the effects of MOS transistor parameters mismatch. In this paper, the Functional Block Diagram (FBD) of already known integrator circuits is modified in such a way that the number of required current mirrors is reduced. Thus, the behavior of the derived integrator topologies, with respect to the effect of MOS transistor parameters mismatch, is improved.A comparison is performed, concerning the performance of the proposed bilinear integrator circuits and those that are already introduced in the literature. For this purpose, a fifth-order Chebyshev lowpass SI filter transfer function was simulated. In the case of the proposed filter configurations, the obtained results show that their performance is improved in terms of the effects of MOS transistor parameters mismatch, DC power dissipation, and total required silicon area.     

A realization of a high-frequency monolithic integrator with low power dissipation and its application to an active RC filter

According as the fine LSI process technique develops, the technique to reduce power dissipation of high-frequency integrated analog circuits is getting more important. This paper describes a design of high-frequency integrator with low power dissipation for monolithic leapfrog filters. In the design of the conventional monolithic integrators, there has been a great difficulty that a high-frequency integrator which can operate at low supply voltage cannot be realized without additional circuits, such as unbalanced-to-balanced conversion circuits and common-mode feedback circuits. The proposed integrator is based on the Miller integrator. By a PNP current mirror circuit, high CMRR is realized. However, the high-frequency characteristic of the integrator is independent of PNP transistors. In addition, it can operate at low supply voltage. The excess phase shift of the integrator is compensated by insertion of the compensation capacitance. The effectiveness of the proposed technique is confirmed by PSPICE simulation. The simulation results of the integrator shows that the common-mode gain is efficiently low and the virtual ground is realized, and that moderate phase compensation can be achieved. The simulation results of the 3rd-order leapfrog filter using the integrator shows that the 50 MHz-cutoff frequency filter is obtained. Its power dissipation in operating 2 V-supply voltage is 5.22 mW.     

Design of a fA wide dynamic range ADC for current sensing

In this paper, optimal dynamic range scaling of ΔΣ ADC using bias current estimation method is proposed. Generally, a different dynamic range scaling gives different feedback factor and effective load capacitance to each integrator in the ΔΣ ADC. It means that power consumption of each integrator strongly depends on the coefficient of the integrator. Therefore, the proposed method estimates which dynamic range scaling consumes the least power to achieve a given settling error. To verify the effectiveness of the proposed method, the noise coupled third order ΔΣ ADC having different dynamic scaling with transistor level opamps was simulated to compare the ADC performance.