Voltage Current Conveyor Transconductance Amplifier Research Articles

A Novel Dual-Mode Dual Type Hysteresis Schmitt Trigger and its Applications using Single Differential Voltage Current Conveyor Transconductance Amplifier

A Novel Dual-Mode Dual Type Hysteresis Schmitt Trigger and its Applications using Single Differential Voltage Current Conveyor Transconductance Amplifier

Mixed-mode Multiphase Sinusoidal Oscillators using Differential Voltage Current Conveyor Transconductance Amplifiers and Only Grounded Passives Components

This article is about mixed-mode multiphase sinusoidal oscillators that are made up of differential voltage current conveyor transconductance amplifier (DVCCTA) and use all the grounded passive components. The proposed multiphase sinusoidal oscillators provide a single DVCCTA, a single grounded resistor and a capacitor for each phase which is suitable for integrated circuit implementation. In addition, the sinusoidal outputs generate currents and voltages simultaneously. The current signals from the outputs have high impedances, which make it easier to connect them directly to the next circuit or stage. The proposed circuits can generate multiphase sinusoidal signals that are both equally phased and in amplitude. The oscillation can be adjusted simultaneously of the frequency of oscillation by the electronic method. A simulation with the PSPICE program and an experiment with commercially available ICs (AD830, AD844, and LM13700N) demonstrated. The results show the efficiency of the circuit is completely consistent with the theory.

A compact floating and grounded memristor model using single active element

Memristor with defined operational specifications is a challenging task that promotes innovation in emulation circuit modelling. This article presents a single active block based compact memristor emulator architecture which is suitable for both floating and grounded circuit topologies. It effectively operates in incremental/decremental modes in both the configurations. The proposed model utilizes only one Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA) as an active block along with a few passive components. It discourages the use of extra sub-circuit components like multiple active blocks, summers and multipliers. The circuit is intended to work at ±1 V of dc power supply and has a power consumption of 8.74 mW. The proposed emulator model exhibits all the characteristics of an ideal memristor with an operating frequency of 12.8 MHz. It has wide working voltage range of 50–500 mV. The memristor model is built and simulated using the TSMC 0.18 μm CMOS process parameter. The reliability and effectiveness of the proposed model is verified through non-ideal, Monte-Carlo, process corner, non-volatility and temperature variation analysis. Furthermore, the memristor prototype is constructed on the breadboard using discrete ICs AD844AN and CA3080. The experimental outcome is found in accordance with the simulation. The applicability of the proposed memristor model is verified by implementing a memristor based Schmitt trigger circuit.

Electronically Tunable Full Wave Precision Rectifier Using DVCCTAs

This work presents a voltage mode scheme of a full-wave precision rectifier circuit using an analog building block differential voltage current conveyor transconductance amplifier (DVCCTA) including five NMOS transistors. The proposed design is essentially suited for low voltage and high-frequency input signals. The operation of the proposed rectifier design depends upon the region of operation of NMOS transistors. The output waveform of the presented rectifier design can be made electronically tunable by controlling the bias voltage. The functional correctness and verification of the presented design are performed using 0.25-µm TSMC technology under the supply voltage of ±1.5 V. The absence of a resistor leads to a minimal parasitic effect. To obtain further insight on the robustness of the circuit, a Monte Carlo simulation and corner analysis are also presented. The circuit is verified experimentally by incorporating a breadboard model with the help of commercially available ICs CA3080 (operational transconductance amplifier) and AD844AN (current feedback operational amplifier) and offers remarkable compliance with both theoretical and simulation outcomes. The presented design has been laid out on Cadence virtuoso, which consumes a chip area of 9044 µm2.

Improved current-mode wave active filter

ABSTRACT In this paper, a resistorless improved wave active filter (WAF) is presented using a comparatively new current-mode building block, namely extra X current-controlled current conveyor (EX-CCCII). The proposed wave active filter is designed in the current mode. The incident and reflected waves are used for designing the basic wave active elements, namely series and shunt inductors (L) and capacitors (C). The novelty of the circuit is that the mathematical operations like lossy integrator, unity gain amplifier, summation, and subtraction, required to realise the wave active elements, are accomplished by judiciously using the port relationships of EXCCCII. As a result of which the proposed circuit is compact and uses only two EXCCCIIs and one grounded capacitor for the realisation of wave elements (L and C). One 3rd and one 4th order Butterworth wave active filters are designed using EX-CCCII-based wave elements and simulated in cadence using 0.18 µm TSMC CMOS technology. The comparison indicates that the proposed WAF uses minimum numbers of analog building blocks (ABBs) and consumes the least power; moreover, the performances such as noise, percentage total harmonic distortion (%THD), and electronic controllability of cut-off frequency of the filters are also reported. Abbreviations: ABB: analog building block; FDNR: frequency-dependent negative resister; WAF: wave active filter; THD: total harmonic distortion; OTA: operational transconductance amplifier; CFOA: current feedback operational amplifier; VDTA: voltage differencing transconductance amplifier; OTRA: operational transresistance amplifier; CCDDCCTA: current-controlled differential difference current conveyor transconductance amplifier; DVCCCTA: differential voltage current-controlled conveyor transconductance amplifier; DVCCTA: differential voltage current conveyor transconductance amplifier; EX-CCCII: extra X current-controlled conveyor

Design of Memcapacitor Emulator using DVCCTA

This research article discusses an analog realization of Memcapacitor using Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA). The proposed Memcapacitor configuration with grounded passive elements is very attractive due to the possibility of making it fully monolithic. In general the commercially unavailable Memcapacitor is difficult to fabricate due to its unique property to exhibit pinched hysteresis loop. Hence, an attempt is made for the design of Memcapacitor emulator using DVCCTA. Finally, PSPICE simulation results for the Memcapacitor based on CMOS implementation are well illustrated in this report by using 0.18µm TSMC CMOS parameter.

PI, PD and PID Controllers Using Single DVCCTA

This paper presents differential voltage current conveyor transconductance amplifier (DVCCTA)-based proportional–derivative (PD), proportional–integral (PI) and proportional–integral–derivative controllers (PID) with electronic tunability. CMOS-based DVCCTA used in the proposed structure is more attractive for IC implementation since all the passive components are grounded. The proportional gain, the integral and derivative time constants can be independently controlled. This paper also presents PD, PI and PID controllers in a single unit using modified DVCCTA. One of the three controllers can be operated at a time by appropriate connection to the input terminals C1, C2 and C3. The analysis of theoretically proposed circuit has been simulated through PSPICE simulations using 0.25 µm Taiwan Semiconductor Manufacturing Company CMOS technology parameter.

Analog Realization of Electronically Tunable Fractional-Order Differ-Integrators

This paper presents simple structures of fractional-order differentiators and fractional-order integrators. For these structures, both current mode and voltage mode designs have been implemented for differential input signals. The analog realizations of these fractional circuits use a single active element, the Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA), and a capacitive fractor. The passive elements present in the capacitive fractor are arranged in parallel RC ladder topology with their consecutive values in geometric progression. In the proposed structures, the capacitive fractor and the resistances connected at different ports of DVCCTA are all grounded, hence, making the designs simpler and less sensitive to the parasitic effects. Apart from this, the other key features of these designs are—electronically tunable, high dynamic range, robust and accurate. Simulations of all the four models are performed using TSMC \(0.25\,\upmu \hbox {m}\) technology in MentorGraphics. The non-ideal analysis of DVCCTA device and Monte Carlo analysis have been studied to validate the robustness of these models. The results obtained are in compliance with their corresponding ideal responses. Comparisons with other active element-based structures have been presented to substantiate the work proposed in this paper.

Quadrature voltage control oscillator with a linear tuning law

New realisation scheme of linear voltage-controlled quadrature oscillator (QO) is proposed. The active building block is electronically tunable (ET) differential voltage current conveyor transconductance (gm) amplifier configured with current feedback amplifier and multiplication mode current conveyor devices. The designs are essentially tuned-inductor–capacitor oscillator, wherein the electronically variable lossless grounded inductor (L) had been simulated at suitable nodes of the active building block. Subsequently, with slight modification of the block, an ET floating-lossless immittance function generation is presented. Effects of device port mismatch error and parasitic capacitances are analysed. Albeit sensitivity relative to port mismatch error is negligible, the parasitic components tend to limit the higher-usable frequency range; appropriate design equations are derived for a true bilinear admittance function realisation and their applications to filter and sinusoid oscillator design are included. Experimental results on the QO with linear fo-tuning law are satisfactorily verified up to 8.7 MHz at low total harmonic distortion.

Single DVCCTA based high frequency incremental/decremental memristor emulator and its application

Memristor emulator based on TiO2 model is introduced. The proposed circuit uses current mode building block DVCCTA (Differential Voltage Current Conveyor Transconductance Amplifier) using 0.25µm CMOS technology. The presented circuit uses single CMOS based DVCCTA, three resistors and one capacitor. It can operate up to 1MHz in both the incremental and decremental configuration by interchanging the connections. Theoretical analysis of the proposed circuit resulting in the equivalent memristance equation is done and non-ideal analysis is also included. PSPICE simulations are performed. Simulation results agree well with theoretical assumption. To verify the practicability of the circuit, PCB prototype has been made using AD844AN and CA3080. The experimental demonstration is carried out for 50kHz and 100kHz. Moreover, the circuit has also been tested for non-volatility features. It is observed from the experimental test result and using 0.25µm CMOS technology that maximum frequency is 10kHz and 50kHz respectively. To check the functionality of the circuit two combinations of memristor are connected in serial and parallel and desired results are obtained. Memristor based high pass filter is also discussed so as to study the memristor behavior in comparison to the resistor.

Single Active Element-Based Tunable Square/Triangular Wave Generator with Grounded Passive Components

This paper presents a novel circuit of tunable square/triangular wave generator based on single active element and grounded passive components. The structure of the proposed generator is simple as it consists of one multiple-output differential voltage current conveyor transconductance amplifier (MO-DVCCTA) as active element and one grounded resistor and one grounded capacitor as passive components. The proposed generator provides triangular wave in voltage mode and square wave in both voltage mode and current mode simultaneously. The proposed generator enjoys the features of availability of square wave in both current mode and voltage mode, electronically tunable duty cycle via DC current over a 93–7% range, electronically and independently adjustable DC level of voltage-mode square wave and triangular wave via an additional DC current, independent and electronic control of amplitude of current-mode square wave by bias current and independent tunability of oscillation frequency by grounded capacitor. Moreover, the operation of the proposed generator at 50% duty cycle exhibits the electronic and independent control of oscillation frequency via bias current also. As an additional feature, the proposed generator exhibits <1% nonlinearity up to a frequency of 123.9 kHz. The maximum temperature coefficient of oscillation frequency over a temperature range of 0–50 \({^{\circ }}\)C is found 185 ppm/\({^{\circ }}\)C which is quite good in view of temperature stability of the oscillation frequency. The prototype of MO-DVCCTA based on commercial ICs has been used in the realization of circuit of the proposed generator. The PSPICE simulation results and experimental results are given to validate the proposed generator.

Inductorless realization of Chua’s oscillator using DVCCTA

This research paper describes a new current mode implementation of Chua's circuit using differential voltage current conveyor transconductance amplifier (DVCCTA) and standard passive components lik...

Approach for third order quadrature oscillator realisation

This paper presents a new approach for third order quadrature oscillator (QO) realisation. It uses a high pass filter and differentiator connected in a feedback loop. A differential voltage current conveyor transconductance amplifier (DVCCTA) is employed to verify the proposed approach. Two circuit topologies of QO have been proposed. Both the topologies utilise two DVCCTA and three grounded capacitors. In addition, the first topology employs a single resistor while the second makes use of two resistors. The circuits exhibit orthogonal control on frequency and condition of oscillation. The quadrature current outputs are available at high output impedance and voltage outputs are also present. The theoretical proposition has been verified through SPICE simulations using 0.25 μm Taiwan semiconductor manufacturing company (TSMC) complementary metal oxide semiconductor (CMOS) technology parameters. Experimental results are also included which corroborate the theoretical propositions and simulated results.

Realization of DVCCTA Based Versatile Modulator

A Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA) based versatile modulator is proposed which can work as an amplitude modulator, frequency modulator, delta modulator, and sigma delta modulator. The modulator operational scheme uses pulse generator as a core and its output is used as carrier signal. A DVCCTA based pulse generator is proposed first and subsequently configured as different modulators. Compact realization is the key feature of the proposed circuit as it uses two DVCCTA; a grounded resistor and a grounded capacitor hence are appropriate for IC realization. The functionality of the proposed circuit is verified through SPICE simulations using TSMC 0.25 μm CMOS process model parameters. The performance parameters such as power dissipation and noise for various modulator schemes are also obtained.

MMCC Based Electronically Tunable Allpass Filters Using Grounded Synthetic Inductor

New circuit implementations of electronically tunable first and second order allpass filter (AP) structures using a Multiplication Mode Current Conveyor (MMCC) building block are presented. The control voltage (V) of the MMCC tunes the desired phase (θ) while the time constant (τ) is adjustable by a Differential Voltage Current Conveyor Transconductance Amplifier (DVCCTA)-based synthetic lossless grounded inductor (L). The circuits are analyzed taking into account the device imperfections which show low active sensitivity features of the designs. The effects of port transfer error (ε) and that of the parasitic capacitances of the active devices had been meticulously examined which indicated that certain deviations in nominal design equations occur; these however, could be minimized with appropriate choice of the circuit passive components. Readily available AD-844 type Current Feedback Amplifier (CFA) elements are utilized for the topology implementation. Satisfactory test results on electronic θ-tunability, upto about 300 KHz, had been verified by PSPICE simulation and with hardware experimentation.

Tunable current-mode and voltage-mode quadrature oscillator using a DVCCTA

A novel tunable current-mode and voltage-mode quadrature oscillator design using a single differential voltage current conveyor transconductance amplifier (DVCCTA) and four all grounded passive elements is presented. The proposed circuit offers two explicit quadrature current outputs and two quadrature voltage outputs. The oscillation condition and oscillation frequency of the proposed oscillator are independently controllable. The use of only grounded passive components makes the proposed circuit ideal for integrated circuit implementation. HSPICE simulation results are given to verify the theoretical analysis.

CMOS realization of single-resistance-controlled and variable frequency dual-mode sinusoidal oscillators employing a single DVCCTA with all-grounded passive components

In this paper, two new designs are proposed for sinusoidal oscillators based on a single differential voltage current conveyor transconductance amplifier (DVCCTA). Each of the proposed circuits comprises a DVCCTA combined with passive components that simultaneously provides both voltage and current outputs. The first circuit is a DVCCTA-based single-resistance-controlled oscillator (SRCO) that provides independent control of the oscillation condition and oscillation frequency by using distinct circuit parameters. The second circuit is a DVCCTA-based variable frequency oscillator (VFO) that can provide independent control of the oscillation frequency by adjusting the bias current of the DVCCTA. In this paper, the DVCCTA and relevant formulations of the proposed oscillator circuits are first introduced, followed by the non-ideal effects, sensitivity analyses, frequency stability discussions, and design considerations. After using the 0.35-μm CMOS technology of the Taiwan Semiconductor Manufacturing Company (TSMC), the HSPICE simulation results confirmed the feasibility of the proposed oscillator circuits.

Universal Biquadratic Filter Employing Single Differential Voltage Current Controlled Conveyor Transconductance Amplifier

This paper presents new realizations of second order voltage mode and current mode universal filters based on a recently reported active element, called the differential voltage current controlled conveyor transconductance amplifier (DVCCCTA). The proposed circuits do not use external resistor. The filter circuits provide all the responses without changing the circuit topology. All the capacitors are virtually grounded. The use of grounded capacitors makes the circuit suitable for monolithic implementation. The pole frequency and quality factor can be adjusted independently with the input bias currents. The non-ideal analysis and the sensitivity analysis have been included. Both the active and passive sensitivities are not more than unity. The filter performances are verified using the PSpice simulations which agree well with theoretical value. 

VM and CM Universal Filters Based on Single DVCCTA

A universal voltage-mode filter (VM) and a current-mode filter (CM) based on recently proposed active building block, namely, differential voltage current conveyor transconductance amplifier (DVCCTA) are proposed. Both the circuits use a single DVCCTA, two capacitors, and a single resistor. The filters enjoy low-sensitivity performance and low component spread and exhibit electronic tunability of filter parameters via bias currents of DVCCTA. SPICE simulation using 0.25 μm TSMC CMOS technology parameters is included to show the workability of the proposed circuits.

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.