Single FDCCII-based mixed-mode biquad filter with eight outputs

The transconductance and the transresistance modes might act as the bridge transferring from voltage-mode to current-mode and vice versa, respectively. A novel mixed-mode (including voltage, current, transconductance, and transresistance modes) biquad filter with one input and seven outputs or two inputs and eight outputs is presented. The proposed filter structure only uses a single fully differential current conveyor (FDCCII), three resistors and two grounded capacitors, which are the least components necessary for realizing voltage, current, transresistance modes all five standard filter functions and transconductance-mode band-pass, high-pass filter functions from eight output terminals. Moreover, the new mixed-mode biquad filter still enjoys (i) the employment of two grounded capacitors (attractive for absorbing shunt parasitic capacitance and ideal for IC implementation), (ii) orthogonal control of ω₀ and Q (easy for tunability), and (iii) high output impedance of three current outputs (good for cascadability). H-Spice simulation results verify the theoretical analysis.     

Versatile multifunction universal voltage-mode biquadratic filter

A new versatile multifunction universal biquadratic filter with four inputs and four outputs employing one differential difference current conveyor, one full differential current conveyor, two grounded capacitors and two grounded resistors is proposed. The proposed configuration can be used as either three-input single-output voltage-mode universal filter with high-input and low-output impedance or single-input four-output voltage-mode multifunction filter with high-input impedance. It still maintains the following advantages: (i) the employment of only two current conveyors, (ii) the employment of only grounded capacitors, (iii) the employment of only grounded resistors, (iv) no need to employ inverting type input signals, (v) no need to impose component choice conditions to realize specific filtering functions and (vi) low active and passive sensitivity performances.     

Electronically tunable mutually coupled circuit using only two active components

A new circuit for realisation of the mutually coupled circuit, which is also called the synthetic transformer, is proposed. The proposed circuit uses two current controlled current conveyor transconductance amplifiers (CC-CCTAs), one grounded resistor and two grounded capacitors. The primary self-inductance, the secondary self-inductance and the mutual inductance can be independently controlled and can be tuned electronically by changing the biasing current of the CC-CCTAs. It uses two grounded capacitors which are suitable from the point of integrated circuit implementation. It has a good sensitivity performance with respect to tracking errors and passive components. The validity of the proposed circuit is demonstrated by PSpice simulations.     

A systematic realization of third-order quadrature oscillator with controllable amplitude

A systematic realization of third-order quadrature oscillator using a voltage-mode non-inverting lowpass filter and a voltage-mode inverting lossless feedback integrator is presented in this paper. The proposed circuit consists of two multiple-output differential voltage current conveyor transconductance amplifiers (MO-DVCCTAs), two grounded resistors and three grounded capacitors. The new circuit provides three quadrature voltage outputs, two high-impedance quadrature current outputs, and one high-impedance current output with controllable amplitude, simultaneously. When the input bias current of the first MO-DVCCTA is a modulating signal, the circuit can generate amplitude modulation or amplitude shift keying signals. The condition of oscillation and the frequency of oscillation can be controlled independently through grounded resistors. The proposed circuit only uses grounded capacitors and grounded resistors, which can be easily implemented as an integrated circuit. The experimental results and H-Spice simulation results are given to confirm the theoretical analysis.     

基于单个CCCCTA接地回转器的系统综合

为综合基于CCCCTA的接地回转器,根据CCCCTA的零-镜模型和接地回转器的节点导纳矩阵,利用节点导纳矩阵扩展法,我们实现了4个相互等效的接地回转器。导出的回转器具有两个特点,一个是通过调节CCCCTA的偏置电流,可以电控调节回转器的参数; 另一个特点是电路仅使用单个CCCCTA。作为一个例子,通过使用导出的回转器之一,我们实现了一个极点频率为1.274MHz、品质因素为4的带通滤波器。计算机仿真证明所导出的电路正确有效。     

First-order allpass filter and sinusoidal oscillators using DDCCs

A voltage-mode first-order allpass filter using one differential difference current conveyor (DDCC), one grounded capacitor and one floating resistor is presented. No passive component matching constraints are required. Because the output impedance of the proposed allpass filter is low, the output terminal can be directly connected to the next stage. Using the proposed first-order allpass filter as a basic building block, a new quadrature oscillator and even-phase sinusoidal oscillators can be obtained. The simulation results confirm the theoretical analysis.     

Electronically tunable multiphase sinusoidal oscillator using translinear current conveyors

A new electronically tunable current-mode multiphase sinusoidal oscillator based on translinear current conveyors is presented. The proposed oscillator circuit, which employs only one translinear current conveyor and one grounded capacitor for each phase, can generate arbitrary N output current equal-amplitude signals that are equally spaced in phase (N being even or odd), all at high output impedance terminals. The frequency of oscillation and the condition of oscillation can be controlled electronically and independently through the bias current of the translinear current conveyor. The proposed structure also has simple circuitry, low-component count, and is highly suitable for integrated circuit implementation. The theoretical results were verified by PSPICE simulation. In addition, the modification of the N sinusoidal oscillators to construct a programmable multiphase oscillator is also discussed.     

High input impedance voltage-mode universal biquadratic filter using two OTAs and one CCII

A three-input and single-output voltage-mode universal biquadratic filter with high input impedance, using only two operational transconductance amplifiers (OTAs), one plus-type second-generation current conveyor (CCII) and two capacitors, is presented. The proposed circuit can realize all the standard filter responses, that is, highpass, bandpass, lowpass, notch and allpass filters, from the same configuration. The proposed circuit has no requirements for component matching conditions.     

Electronically tunable floating inductance simulator

In this letter, a new floating inductance simulator circuit is presented. The proposed structure consists of only one grounded capacitor without any external resistors and two different active elements. The active elements are dual-output current-controlled current conveyor (DO-CCCII) and operational transconductance amplifier (OTA). The proposed inductance simulator can be tuned electronically by changing the biasing current of the DO-CCCIIs or by changing the current of the OTA. Moreover, the circuit does not require any conditions of component matching. It has a good sensitivity performance with respect to tracking errors. As an application, the proposed inductance simulator is used to construct a fourth-order resistively terminated LC band-pass filter. The theoretical analysis is verified by the SPICE simulation results.     

Voltage-mode quadrature sinusoidal oscillator with current tunable properties

This letter presents a realization of voltage-mode quadrature sinusoidal oscillator with independent current tunable frequency of oscillation. The circuit uses a single differential voltage current conveyor transconductance amplifier (DVCCTA) as the active building block and four all grounded passive elements. PSPICE simulation results have been included to verify the theoretical results.     

Novel cascadable current-mode first order all-pass sections

This paper presents some new current mode first order all-pass sections with grounded components employing a modified current conveyor. The new circuits are ideal for current-mode cascading by possessing high output impedance. As an application of the circuits, a new quadrature oscillator is also given. The theory is validated through PSPICE simulation using 0.5μ CMOS parameters.     

Current‐mode quadrature oscillator using current differencing transconductance amplifiers

This article presents a new electronically tunable single‐element‐controlled current‐mode quadrature sinusoidal oscillator circuit using current differencing transconductance amplifiers (CDTAs). The proposed oscillator is consisted of two CDTAs, two grounded capacitors and one grounded resistor, which is beneficial to monolithic integrated circuit implementation both in CMOS and bipolar technologies. The condition of oscillation and the frequency of oscillation are independently controllable. The frequency of oscillation can also be electronically controlled by adjusting the bias current of CDTA. The circuit provides four quadrature current outputs and two quadrature voltage outputs. The current output terminals possess high impedance level. PSPICE simulation results are used to verify the performance of the proposed circuit implemented at the transistor level. The measurement results support the computer simulations.     

Voltage-mode universal filter with one input and five outputs using DDCCTAs and all-grounded passive components

This paper presents a versatile voltage-mode universal active filter with one input and five output terminals. The proposed circuit is based on using the recently reported active building block, namely differential difference current conveyor transconductance amplifier (DDCCTA). It employs two DDCCTAs as active elements together with two resistors and two capacitors as passive elements, which are all grounded. The circuit simultaneously realizes all the five standard biquadratic filter functions; i.e., lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), without changing circuit topology. The proposed circuit also has the advantage of high-input impedance terminal, and exhibits electronic tunability of its important parameters through the bias current of the DDCCTA as well as low sensitivity performance. PSPICE simulations using 0.5 μm MIETEC CMOS process are used to validate the theoretical predictions.     

New electronically tunable current-mode universal biquad filter using translinear current conveyors

In this study, a new electronically tunable current-mode universal filter with two inputs and two outputs employing one translinear current conveyor, one translinear current conveyor with controlled current gain and two grounded capacitors is presented. The proposed circuit offers the following attractive features: realisation of low-pass, band-pass, high-pass, band-stop and all-pass current responses from the same configuration; employment of the minimum active and passive components; no requirement of component matching conditions; independent current-control of the parameters natural frequency (ω_o) and quality factor (Q); low active and passive sensitivities; and high impedance output. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theory.     

基于单个CCCTA的高带外抑制电流模式n阶滤波器设计

提出了一个电流传输级联跨导放大器（CCCTA）,并基于此器件设计了一种具有高带外抑制性能的电流模式n阶多功能滤波器。该滤波器仅使用1个CCCTA和n个接地电容,可同时实现高通、低通、带通、带阻以及全通滤波功能。电路具有结构简单、功耗低、抗干扰能力强、容易集成等优点。PSPICE仿真和瞬态测试结果验证表明,所设计的电路与理论分析相吻合。     

Universal active current filters using single second-generation current conveyor

Two novel universal active current filters, one of which has multiple outputs and the other of which has a single output and high output impedance, employing a single negative second-generation current conveyor, three position-fixed capacitors and four/five position-fixed resistors are proposed. The proposed networks with the advantages of low passive sensitivities can obtain second-order lowpass, bandpass, highpass, notch and allpass current signals by adjusting the magnitudes of a grounded resistor and a grounded capacitor provided that another resistor is separable. The resonance angular frequency and quality factor are insensitive to the current tracking error of the nonideal CCII.<>     

On the Realization of Simulated Inductors with Reduced Parasitic Impedance Effects

In this paper, a method for reducing the parasitic impedance effects of the current feedback operational amplifiers (CFOAs) in an inductor simulator at low frequencies is proposed. Also, two novel grounded inductors employing a current follower (CF) and a second generation current conveyor (CCII) are given to illustrate the parasitic reduction technique clearly. The low frequency restrictions of the proposed inductors due to terminal parasitic resistances can be improved by using the presented parasitic impedance reduction technique. SPICE simulations show that the presented inductor employing CFOAs in a voltage-mode (VM) band-pass and high-pass filter application has lower parasitic effects at low frequencies. In addition to simulation results, experimental test results are given to verify the theory.     

A novel Alienor-based heuristic for the optimal design of analog circuits

A heuristic for solving (non-linear and constrained) analog optimization problems is proposed. The method is based on an approximation of multi-variable multi-objective problems by a mono-objective problem of one variable: the Alienor technique and a normalization technique are used for this purpose. Application to the optimal design of an inverted CMOS current conveyor and a class AB grounded gate switched current memory cell are given.     

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。     

Floating Immittance Function Simulator and Its Applications

A new floating immittance function simulator circuit is proposed using two different active elements, a dual-output second generation current conveyor (DO-CCII) and an operational transconductance amplifier (OTA). The presented circuit can realize a positive and negative floating inductor, capacitor and resistor depending on the passive component selection. Since the passive elements are all grounded, this circuit is suitable for fully integrated circuit design. The circuit does not require any component matching conditions, and it has a good sensitivity performance with respect to tracking errors. Moreover, the proposed positive and negative inductance, capacitor and resistor simulator can be tuned electronically by changing the biasing current of the OTA or can be controlled through the grounded resistor or capacitor. The proposed floating inductor simulator circuit is demonstrated by using a SPICE simulation for 0.35 μm TSMC CMOS technology. The proposed circuit consumes an average power of 1 mW using ±1.5 V supply voltages.