采用MO-CFTA和MO-CCCCTA的电流模式KHN滤波器

针对现有电流模式Kerwin-Huelsman-Newcomb(KHN)滤波器的不足,借助KHN电路对应的信号流图,设计了一种由一个多输出电流跟随跨导放大器(MO-CFTA)和一个多输出电流控制电流传输跨导放大器(MO-CCCCTA)及2个接地电容构成的电流模式KHN滤波器。它能同时实现低通(LP)、高通(HP)、带通(BP)、带阻(BR)和全通(AP)5种滤波功能,其极点频率与品质因数能由偏置电流独立调整,并具有无源与有源灵敏度低、使用元件少、输入阻抗低和输出阻抗高、适于集成等优点。采用PSPICE对电路进行了仿真,所得结果验证了理论分析的正确性。     

基于单片MO-CDTA的高输出阻抗电流模式KHN滤波器

提出了一个多输出电流差分跨导放大器(MO-CDTA),并利用它设计了一个电流模式KHN滤波器。该电路仅使用1个MO-CDTA和2个接地电容,不仅能同时实现高通、带通和低通电流转移函数,而且输入端虚地、输出端具有高阻抗。借助于所给的偏置电路,能实现极点频率和品质因数独立、线性地电控调谐。仿真结果表明,设计的电路正确有效。     

一种新颖的电压模式通用二阶CFA滤波器设计

提出了一种仅用2个电流反馈放大器(CFA)实现的三输入单输出电压模式通用二阶滤波器电路。该电路由2个电流反馈放大器(CFA)、2个电容、3个电阻构成,他能实现二阶低通、带通、高通、陷波、全通滤波函数。分析了该电路的电压传输函数及电路参数,并用PSpice对该电路进行了仿真,仿真结果表明,该电路设计正确,电路结构简单,所用元器件少。     

基于CFOA的低通、带通和高通滤波器

用3个电流反馈运算放大器(Current-feedback Operational Amplifier，CFOA)、3个接地电容、3个电阻和1个浮地电阻的组合提出了一种高输入阻抗低通、带通和高通滤波器电路．该滤波器电路有如下特征：用同一结构实现了低通、带通和高通滤波器，无需元件匹配，接地电容的使用使得该电路适合于集成实现，很低的输出阻抗使得该电路在电压模式电路中级联比较方便．     

基于第三代电流传输器的有源滤波器的导出

阐述了由电压模式有源RC滤波器导出基于电流传输器(CCIII)的电流模式连续时间滤波器的方法.即由运算放大器(OA)滤波器导出CC滤波器;导出的电流模式2阶滤波器结构简单,能实现2阶低通、高通、带通滤波,不仅所有无源和有源灵敏度都很低,而且当无源参数确定后,有源参数对极点频率W0不产生影响,W0保持恒定.HSPICE仿真表明,提出的电路是可行的.     

基于CDCTA和MOCCII的低功耗电流模式n阶滤波器

提出了一种电流模式多输入单输出的n阶滤波器。该电路包括一个电流差分级联跨导放大器(CDCTA)、一个多输出第二代电流传输器(MOCCII)和若干接地电容。无需改变电路内部的结构和器件数目,仅通过选择合适的输入电流信号就可实现任意阶的高通、低通、带通、带阻等滤波功能。该滤波器结构简单,输出阻抗高,易于集成,频带宽,功耗低,滤波性能优越。基于TSMC 0.18 μm CMOS工艺,采用Pspice对电路进行了仿真,结果证明了该滤波器理论分析的正确性。     

基于MOCCCⅡ的双模式二阶通用滤波器

提出了一种基于多输出端口电流控制电流传输器(MOCCCII,multiple outputs current controlled conveyor)的双模式二阶通用滤波器,该滤波器结构简单,仅由5个有源器件、2个接地电容构成,无须外接电阻.该电路在不改变内部电路结构的情况下能实现电压模式和电流模式滤波器,且每一种工作模式都能实现高通、低通、带通等多种滤波功能,因此该电路具有通用性.面向实际电路完成了PSPICE仿真,结果表明提出的电路正确有效.     

基于MOCCCII的双模式二阶通用滤波器

提出了一种基于多输出端口电流控制电流传输器(MOCCCII,multiple outputs current controlled conveyor)的双模式二阶通用滤波器,该滤波器结构简单,仅由5个有源器件、2个接地电容构成, 无须外接电阻.该电路在不改变内部电路结构的情况下能实现电压模式和电流模式滤波器,且每一种工作模式都能实现高通、低通、带通等多种滤波功能,因此该电路具有通用性.面向实际电路完成了PSPICE仿真,结果表明提出的电路正确有效.     

基于MO-CCCDTA的电控调谐电流模式六阶椭圆带通滤波器

提出了一个多输出电流差分跨导放大器(MO-CCCDTA),利用它设计了一个电流模式二阶带通、二阶高通带阻和二阶低通带阻电路,以此为基础,利用级联法设计了电流模式六阶椭圆带通滤波器.该滤波器仅使用3个MO-CCCDTA、1个CDTA和7个电容,通过调节偏置电流,各滤波器参数均能被电控调谐.计算机仿真表明电路正确有效.     

电流模式N阶CDBA-RC通用滤波器的系统设计

该文提出了利用电流差分缓冲放大器CDBA(the Current Differencing Buffered Amplifier)实现n阶电流模式滤波器的方法。基于信号流图给出了系统的设计公式,并举例设计了5阶Butterworth低通、高通及4阶Butterworth带通滤波器。PSPICE仿真表明,结果与理论分析完全吻合。该滤波器不仅电路结构简单,而且用的元件数目很少。     

适宜集成的KHN滤波器设计

为了获得高精度的电压模KHN滤波器,以Deboo积分器为原型,先给出一种高精度、易集成的变形Deboo积分器,再借助Meson公式,用变形Deboo积分器设计出极点频率为31.8 kHz、品质因素为1、通带增益为2的通用电压模KHN滤波器.该电路不仅可同时实现高通、带通和低通输出,且极点频率与品质因素能实现正交、精确调节,电路的参数取决于电阻比,两积分电容接地,因而适合单片集成技术.计算机仿真结果与理论分析一致.     

Current mode high-frequency KHN filter employing differential class AB log domain integrator

In this study, a current mode log domain differential Class AB biquad filter based on Kerwin–Huelsman–Newcomb (KHN) structure has been synthesized by using the state-space method and by adopting translinear circuits. The proposed circuit can produce second-order low pass, band pass, high pass, all pass, and notch filter characteristics. The circuit is synthesized for high-frequency applications, i.e. around 100 MHz. The natural frequency and Q quality factor of the filter can be tuned electronically by varying the currents of current sources. Moreover, by varying currents of selected current sources, one can change the characteristics of the notch filter to generate general, low pass, and high pass notch filters. The designed circuit is simulated in both time domain and frequency domain in PSpice by using both idealized and NE 600 series type real transistors that are suitable for high-frequency operations. The frequency as well as time domain responses are found to be as expected. In addition to these simulations, THD and noise analysis are carried out. The details of obtained results are given.     

Realization of Voltage and Current Mode KHN Biquads Using CCCIIs

In this work, new Kerwin-Huelsman-Newcomb (KHN) biquads employing current-controlled current conveyors (CCCIIs) in voltage-mode (VM) as well as in current-mode (CM) are presented. The parameters of the proposed circuits can be electronically controlled thanks to the tunability properties of the CCCIIs. The VM circuit is derived from a previously reported one by modifying its summing circuit and replacing the current conveyor(CCIIs) and resistors at their x-input terminals with CCCIIs. On the other hand, the CM circuit is derived from the adjoint graph of the signal-flow graph corresponding to the classical KHN circuit. This circuit is a multi-input single-output CM universal filter, which offers all the main advantages of the CM circuits as well as those of the classical KHN circuit. In addition to the three basic filter responses, they also allow the realization of the notch and the all pass responses.     

A Modified CDTA (MCDTA) and Its Applications: Designing Current-Mode Sixth-Order Elliptic Band-Pass Filter

This paper presents a modified current differencing transconductance amplifier (MCDTA) and the MCDTA based KHN filter with high output impedance. Moreover, the paper gives a current-mode sixth-order elliptic band-pass filter by means of cascade method. The filter with only three MCDTAs, six grounded capacitors and four resistors is easy to be integrated. Its pole frequency can be determined electronically through adjusting bias currents of MCDTA. The results of circuit simulations are in agreement with the designed parameters.     

Current-mode KHN-equivalent biquad using CDBAs

A new Kerwin-Huelsman-Newcomb (KHN)-equivalent biquad, operating in the current mode (CM), is proposed. The proposed circuit is derived from the adjoint graph of the signal flow graph corresponding to the classical KHN circuit. The derived circuit is a CM universal filter, which offers all the main advantages of CM circuits as well as those of the classical KHN circuit. The proposed circuit employs three current differencing buffered amplifiers (CDBAs) as active elements. In addition to the three basic filter responses, it also allows the realisation of the notch and allpass responses without requiring any element matching conditions     

Integrable Current-Mode Filter Realisation using Dual-Output Current Conveyors for Low-Frequency Operation

The realisation criteria of continuous-time current-mode (CM) active filters for low frequency operation are investigated. New lossless and lossy integrators for low frequency operation using dual-output current conveyors (DO-CCII) are proposed. Basing on these building blocks, a CM universal filter with low natural frequencies suitable for integrated circuit implementation is presented. Using the proposed filter, natural frequencies as low as a few ten hertz can be achieved on an integrated circuit chip without using any external passive components. The proposed circuit simultaneously produces three basic filter responses at its high impedance outputs and it has good passive and active sensitivity performance.     

Log-domain all pass filter based on integrators

A new all-pass (AP) Log-domain filter is presented. The circuit is based on integrator loop and the current sources. The filter circuit has a very simple structure since it uses only bipolar junction transistors (BJT’s) and a grounded capacitor. The configuration offers large dynamic range at low power supply and higher frequency operation. The filter has a large bandwidth due to its inherent current-mode (CM) nature and Log-domain properties. Phase angle can be electronically tuned through the bias current. The circuit can be implemented in integrated form. PSPICE simulations are given to confirm the theoretical analysis.     

有源模拟滤波器的快速协同设计方法

为了解决有源模拟滤波器传递特性函数设计中手工计算方法复杂、时间长,查表法精度不高的问题,提出了一种快速协同设计方法,该方法先通过在MATLAB环境下将基于频率变换的有源模拟滤波器传递函数设计方法程序化,之后只需给出滤波器电压衰减设计指标和边界频率即可快速获得滤波器传递函数或其二阶级联传递函数中各多项式的系数并在此基础上...     

A Novel High CMRR High Input Impedance Differential Voltage-Mode KHN-Biquad Employing DO-DDCCs

In this work, a novel circuit configuration for realizing a differential voltage-mode Kerwin-Huelsman-Newcomb (KHN) biquad filter with high common-mode rejection ratio (CMRR) is presented. The proposed circuit is based on using the dual output differential difference current conveyor (DO-DDCC). The circuit uses three DO-DDCCs, two capacitors and five resistors. All the passive elements are grounded, which is important in integrated circuit implementation point of view. The differential voltage input signal is applied to high input impedance terminals, which is important in the voltage-mode operations. SPICE simulation results are included to verify the theory.     

新颖的基于CCⅡ的电压模式二阶滤波器

提出了一个新颖的基于同相第二代电流传输器的电压模式滤波器的形式电路，根据该形式电路可以产生低通，带通，高通二阶滤波器。所有滤波器地无源ＲＣ元件全部接地，便于集成，且具有很低的无源灵敏度，极点增益及角频率，品质因数均可调节。