Operational Transresistance Amplifier Research Articles

On Prognosis of Technological Process to Increase the Integration Rate of Elements in the Framework of an Operational Transresistance Amplifier

On Prognosis of Technological Process to Increase the Integration Rate of Elements in the Framework of an Operational Transresistance Amplifier

Novel simulator designed for grounded negative inductance with lossless characteristics incorporated with single OTRA

This article introduces a novel design of a simulator for grounded lossless negative inductance by using an active element -single Operational Trans Resistance Amplifier (OTRA) and four passive components. Without interrupting the condition of realization of inductance, the value of the simulated inductance can be independently administered by a MOS based resistor. For validation of the analytical elucidation PSPICE simulation results are used. Moreover, sensitivity analysis, Monte-Carlo simulation, temperature analysis, and % of total harmonic distortion (%THD) are also investigated to verify the functionality of the proposed circuit. As an application claim of the projected configuration, an inductance nullification circuit is also implemented that exposes that the proposed negative inductance simulator may be used to cancel or reduce the effective inductance in a circuit. The Analog Design Environment tool of Cadence Virtuoso is employed for designing the layout of the OTRA.

Single operational transresistance amplifier‐based grounded resistance‐controlled synthetic inductor configuration

AbstractIn this paper, a grounded lossy inductance (parallel RL type) simulator circuit employing an operational transresistance amplifier (OTRA), five resistors, and a virtually grounded capacitor is proposed. The value of simulated inductor can be controlled independently through a grounded resistance and/or virtually grounded capacitor without affecting the parallel equivalent resistance. Application examples using the presented lossy inductor have been provided. The performance of the application examples has been verified by sample experimental results employing an OTRA implemented using AD844‐type current feedback operational amplifiers.

Third order inverse multifunction filter employing MOS resistors and capacitors

AbstractThis paper presents a systematic approach for the realization of multifunction filter that includes third order inverse low pass filter (ILPF), band pass filter (IBPF), and high pass filter (IHPF) using two Operational Transresistance Amplifiers (OTRAs), MOS resistors, and few number of capacitors. An operational activity of inverse filter configuration (IFC) can be easily realized by proper selection of switches. In ideal case, third order of the filter characterizes a total roll‐off of 60 dB/decade but the proposed design offers a roll‐off in the range of 48.09 dB/decade to 57.74 dB/decade which may arises due to passive component tolerance and some design parameters. The proposed design brings an improvement in roll‐off around 20%–44% in comparison to existing literatures. The multifunction filter frequency response (ILPF, IBPF, and IHPF) is observed by using PSPICE simulation in which the core of the filter “OTRA” is integrated with 180 nm Taiwan Semiconductor Manufacturing Company (TSMC) CMOS technology parameter. In addition to simulation results, hardware implementation of the proposed filter configuration validates the theoretical aspect of filter design.

Inverse Analog Filters: History, Progress and Unresolved Issues

This paper traces the history of the evolution of inverse analog filters (IAF) and presents a review of the progress made in this area to date. The paper, thus, presents the current state-of-the art of IAFs by providing an appraisal of a variety of realizations of IAFs using commercially available active building blocks (ABB), such as operational amplifiers (Op-amp), operational transconductance amplifiers (OTA), current conveyors (CC) and current feedback operational amplifiers (CFOA) as well as those realized with newer active building blocks of more recent origin, such as operational transresistance amplifiers (OTRA), current differencing buffered amplifiers (CDBA) and variants of current conveyors which, although not available as off-the-shelf ICs yet, can be implemented as complementary metal–oxide–semiconductors (CMOS) or be realized in discrete form using other commercially available integrated circuits (IC). In the end, some issues related to IAFs have been highlighted which need further investigation.

Realization of a reconfigurable Butterworth and Bessel filter using single operational transresistance amplifier and study of their performance

AbstractIn this article, a single operational transresistance amplifier (OTRA) based realization of second order low‐pass (LP), high‐pass (HP), band‐pass (BP), band‐reject (BR), and all‐pass (AP) filter and their individual performance analysis: noise, temperature, and worst‐case analysis have been presented. The proposed circuit can be reconfigured as Butterworth and Bessel filter by changing the values of passive components. The presented filters are suitable for MOS‐C implementation, which facilitates tuning of cut‐off/center frequency and quality factor electronically. The proposed circuits are analyzed theoretically, simulated and experimentally verified in laboratory. All the simulations are performed with CMOS model of OTRA (180 nm) in SPICE and experimentally verified with AD844AN IC. The experimental and simulation results are matching closely. The result obtained from post‐layout simulation of the proposed Butterworth LP filter confirms the feasibility of the design. Finally working of the proposed all‐pass filter is established by the design of a buffer and quadrature oscillator.

A New Realization of Third-Order Inverse Bandpass Filter and Its Application as an Oscillator

A new operational transresistance amplifier (OTRA)-based third-order inverse bandpass filter (IBPF) is presented in this paper. To illustrate an application of the presented IBPF, the proposed configuration is used to implement a third-order quadrature oscillator (TOQO). Furthermore, the nonideal behavior of the proposed topologies has been examined using a single-pole model of the OTRA. It is perceived that for high-frequency applications, the effect of nonidealities may be eliminated through self-compensation. Passive sensitivities are computed and are found to be less than half, rendering proposed topologies insensitive to component variations. Phase noise study and frequency stability analysis have been carried out and found that the proposed TOQO enjoys good frequency stability. The proposed circuits’ workability is verified through an Analog Design Environment (ADE) Spectre tool provided by Cadence Virtuoso using 0.18 [Formula: see text]m CMOS gpdk process parameters. Monte Carlo statistical analysis is also carried out to assess the prefabrication performances. Total harmonic distortion (THD) for the proposed IBPF is found to be less than 5%. Pre- and post-layout simulations are also included to affirm the theory. Excellent agreement among simulation results and theory is observed.

Realization of SIMO biquad filters and quadrature sinusoidal oscillators using OTRAs

In this communication, two single-input multiple-output (SIMO) type biquad filters employing operational transresistance amplifiers (OTRAs) have been presented. Various parameters of the proposed filter circuits viz. pole frequency (ɷ), pole quality factor (Q) and the gain are independently controllable. The proposed filter configurations can also be converted into low frequency oscillators with fully uncoupled control of condition of oscillation and frequency of oscillation with quadrature output voltages. The active and passive sensitivities of the proposed circuits have been found to be small. SPICE simulation results and experimental validation of the proposed circuits employing OTRAs realized with AD844 type CFOAs have also been presented.

Practically Realizable Circuits for OTRA and their Implementation in Oscillators

In this paper, practical circuits for operational transresistance amplifier (OTRA) realizable in lab using commercial ICs have been designed and proposed. 3 structures based on operational amplifier (OPAMP-LM741), operational transconductance amplifier (OTA-CA3080) and current conveyors II (AD844) have been proposed. In these proposed designs, conditions to mimic the current-voltage behavior of OTRA have been formulated using active and passive components. Moreover, these components are also used to achieve flexibility in transresistance gain of implemented OTRA. The behavior of the proposed OTRA structures have been validated using LTSPICE. Furthermore, to represent practical usability of these designs oscillator circuit have been designed and implemented on software and experimentally also on bread board. All the results prove the OTRA operation of the designed circuits and their usability in the practical environment.

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

Two implementations of fractional-order relaxation oscillators

This work proposes general formulas for designing two different topologies of fractional-order relaxation oscillators. One topology contains an Operational Amplifier and the other one relies on an Operational Trans-Resistance Amplifier. The design procedure hinges on the general fractional-order natural and step responses of RC, which is proved in this work depending on Mittag Leffler function. The proposed topologies can be controlled to generate symmetrical and non-symmetrical square wave signals. They also benefit from the employment of fractional-order capacitors (FOCs), which makes it possible to obtain higher frequencies using simple components. Furthermore, these topologies are verified through numerical solutions, circuit simulations, and experimental implementations. This encourages the authors to build circuit emulators for the FOC, which is achieved by applying the Foster-I synthesizing technique to the Matsuda’s approximation of $$s^\alpha$$.

Electronic Tuning Square-Wave Generators with Improved Linearity Using Operational Transresistance Amplifier

Two new electronic tuning current-mode square-wave generators are introduced in the ensuing paper. In the first proposed square-wave generator circuit, one Operational Trans-resistance Amplifier (OTRA) and two passive components are involved, along with two NMOS depletion mode transistors. This circuit generates a square-wave with almost equal and fixed duty cycles. The second proposed circuit is able to control both on-duty and off-duty cycles independently with the help of two passive components, two NMOS depletion mode transistors, and two diodes connected to the circuit. The frequency of the proposed circuits can be adjusted with the passive components connected to the circuit. Moreover, electronic tuning can also be achieved with the proposed circuits. The measured results that are included in the paper show the linear variation of a time period as compared with existing OTRA based square waveform generator. The performance of the proposed circuits is examined while using SPICE models. These circuits are built on a laboratory breadboard using commercially available Current Feedback Operational Amplifier (AD844 AN) and passive components are connected externally and tested for square waveform generation. The obtained results demonstrate good agreement with the theoretical values.

A Class of Differentiator-Based Multifunction Biquad Filters Using OTRAs

This paper presents Signal Flow Graph (SFG) approach-based realization of Single Input Multiple Output (SIMO) filter topologies. A differentiator is placed as basic building block. A total of sixteen variants are derived from the proposed differentiator-based SFG. The Operational Trans-Resistance Amplifier (OTRA), an active block having low parasitics at input terminals, is used to validate the proposed methodology. All the derived filter structures use three OTRAs, six resistors and two capacitors. The filter performance parameters can be adjusted independently. The functional verification of the proposed method is done via SPICE simulations using 0.18 μm CMOS technology parameters from MOSIS.

New Electronically Tunable Low-frequency Quadrature Oscillator Using Operational Transresistance Amplifier

ABSTRACT This paper describes, a new realization of electronically tunable low-frequency quadrature sinusoidal oscillator (LFSO) based on Operational transresistance amplifier (OTRA). The proposed structure employs two OTRAs, along with four resistors and three capacitors. The notable properties of the proposed oscillator are: (1) it bares independent controllability of frequency of oscillation (FO) through resistors without altering the condition of oscillation (CO) and vice versa; (2) suitable for MOS-C realization making FO electronically tunable (3) exhibits low passive sensitivities (4) enjoys good frequency stability properties. Besides, the roots of the characteristic equation are evaluated to calculate the condition for startup oscillations, which results in altering the property of uncoupling tuning between CO and FO to orthogonal tuning. Furthermore, the nonideal behaviour of proposed LFSO has been examined using single pole model of the OTRA. The proposed LFSO was simulated using Spectre in Cadence employing generic Process Design Kit (GPDK) 0.18 μm CMOS process. The post-layout, schematic-driven simulation results obtained agree firmly with the theoretical formulations. The total harmonic distortion (THD) is found to be below 3%.

Design of Bessel High Order All Pass Filter Based on AN OTRA

This paper features a single-input single-output (SISO). The suggested circuit is depend on OTRA which is referred as operational transresistance amplifier. and OTRA recommended on the parameters of its increasing slew rate and large bandwidth as compared to conventional circuit containing operational amplifier. In this paper Bessel Higher order All Pass filter structure are described and their simulation is carried out in PSPICE with the help of 0.5μm CMOS technology and simulation result follows the theoretical approach.

Fractional Order High Pass Filter Based on Operational Transresistance Amplifier with Three Fractional Capacitors of Different Order

Design, realization and performance evaluation of fractional order high pass filter based on Operational Transresistance Amplifier (OTRA) using three fractional elements of different order α, β, γ are presented in this paper. The projected circuit uses a single active current mode device i.e. OTRA and utilizes fractional capacitors of varying orders to boost the design flexibility. The design equations for fractional order high pass filter are computed from the transfer function. The paper elaborates the impact of fractional order elements of varying order on the frequency response of the filter. Subsequently, the sensitivity and stability of the transfer function of the proposed filter are also analyzed. The potential usefulness of the proposed filter is additionally incontestable through the Total Harmonic Distortion (THD), Power Supply Rejection Ratio (PSRR), Temperature sweep, Corner, Supply Voltage variation and Noise Analysis. It has been observed that the proposed pass filter in fractional domain supported OTRA provides greater flexibility in controlling the magnitude characteristics.

Operational Transresistance Amplifier Based Wienbridge Oscillator and Its Harmonic Analysis

In this paper, operational transresistance amplifier (OTRA) based Wien bridge oscillator is presented which uses an OTRA, two RC sections, and a buffer. The frequency of oscillation and the condition of oscillation have been derived, and the effect of device non-ideality on these parameters has also been analyzed. Further, harmonic analysis is carried out to characterize the linear performance of the proposed oscillator. Workability of the proposed Wien bridge oscillator is verified through SPICE simulations followed by experimental results. The total harmonic distortion (THD) is calculated and found to be less than 1%. Low THD value is a significant performance criterion for many high frequency applications.

Generation of OTRA-Based Inverse All Pass and Inverse Band Reject Filters

By utilizing two new operational transresistance amplifier (OTRA)-based generic configurations, we have discussed ten second-order inverse band reject filter circuits and 12 inverse all pass filter circuits. The usability of the inverse filter configurations has been established by SPICE simulations and also by hardware experimentation. In these experiments, integrated circuit from analogue devices, namely AD844-type current feedback operational amplifier, has been used to realize the behaviour of OTRA.

New sinusoidal oscillator configurations using operational transresistance amplifier

SummaryThe objective of this brief is to introduce four new structures of electronically tunable sinusoidal oscillators (SOs) designed using operational transresistance amplifier (OTRA). Each of the proposed SO consists of forward path derived from a generic structure along with one/two OTRA‐based resistive gain stages or differentiator in its feedback path. All the proposed SOs enjoy independent tuning of the frequency of oscillation (FO) through resistors without affecting the condition of oscillation (CO). Further, all topologies are found to exhibit low fo sensitivities at all frequencies with respect to circuit parameters, and the second topology is capable of achieving very low frequencies (VLFs) using less RC component spread and provides linear tuning too. The fourth circuit provides quadrature output. The proposed SOs have been successfully implemented and verified in 180‐nm CMOS technology node using ADE (analog design environment) tool Cadence Virtuoso. Both prelayout and postlayout simulation results have been included. To assess the oscillator prefabrication performances, Monte Carlo and process‐voltage‐temperature (PVT) analyses have been performed. The total harmonic distortion (THD) is observed to be less than 3.5%.

Full-Phase Operation Transresistance-Mode Precision Full-Wave Rectifier Designs Using Single Operational Transresistance Amplifier

This study proposed the designs of two full-phase operation transresistance-mode (TRM) precision full-wave rectifiers. The first circuit consisted of a single operational transresistance amplifier (OTRA), four diodes, and a resistor. The second scheme was an OTRA combined with a full metal-oxide semiconductor field-effect transistor-based design, which is preferable for integrated circuit implementation because no passive components are used in the circuit topology. Based on our literature review, this is the first study that discussed a full-phase operation transresistance-mode precision full-wave rectifier consisting of a single OTRA and few passive components. In this paper, several previously reported precision full-wave rectifiers consisting of various active devices are first reviewed followed by the proposed OTRA-based transresistance-mode precision full-wave rectifiers and an analysis of nonideal effects. Furthermore, computer simulations and experimental results are presented to verify the validity of the proposed circuits, which were consistent with the theoretical predictions.