Operational Transresistance Amplifier Research Articles

Novel Two OTRA-Based Grounded Immitance Simulator Topologies

Three new operational transresistance amplifier (OTRA)-based grounded parallel immitance simulator topologies are presented. The proposed circuits use two OTRAs and require fewer passive components than most of the counterparts in the literature. The performance of the proposed immitance simulators is demonstrated on a fourth-order bandpass filter. PSPICE simulation results are included to verify theory.

Novel Transimpedance Type First-Order All-Pass Filter Using Single Otra

Summary A novel transimpedance-mode first-order all-pass filter configuration is proposed. It uses a single operational transresistance amplifier (OTRA) and few passive components. The proposed circuit is structurally all-pass that does not impose any component matching condition. The proposed circuit is insensitive to parasitic input capacitances and input resistances due to the internally grounded input terminals of the OTRA. It provides an alternative realization of phase equalizers for analog signal processing applications by providing also current-to-voltage conversion. The theoretical results are verified with PSPICE simulations using a CMOS realization of OTRA.

A Novel Single-Resistance-Controlled Sinusoidal Oscillator Employing Single Operational Transresistance Amplifier

A novel operational transresistance amplifier (OTRA)-based single-resistance-controlled sinusoidal oscillator (SRCO) is proposed. It uses single OTRA, three resistors and two capacitors. To the best knowledge of author, this is the first oscillator constructed with single OTRA. The oscillator circuit provides independent control of oscillation frequency without disturbing oscillation condition by a resistor. It has also low passive sensitivities. The oscillator circuit is insensitive to parasitic input capacitances and input resistances due to zero internally grounded input terminals of OTRA. PSPICE simulations are given to verify the theoretical analysis.

Bipolar low-power operational transresistance amplifier based on first generation current conveyor

A new class AB bipolar transresistance topology suitable for low power applications is presented. The circuit uses a positive first generation current conveyor (CCI+) as floating input stage. Simulation results, using nominal parameters for the bipolar transistors arrays HFA3127 and HFA3128 from Intersil Semiconductor, are presented to demonstrate the amplifier performance. Simulated performances give an 85 dB low frequency open-loop gain for a total power consumption of 352 /spl mu/W at 3 V supply voltage. To demonstrate the principle, the operational amplifier is used to implement inverting and noninverting amplifiers, for which the analysis, simulations, and experimental results are given on a prototype using bipolar transistor arrays.

Voltage-mode MOSFET-C filters using operational transresistance amplifiers (OTRAs) with reduced parasitic capacitance effect

The MOSFET-C integrator with reduced parasitic capacitance effect using operational transresistance amplifiers is proposed and experimental results are demonstrated. The bandwidths of these circuits are independent of their gains. The required capacitors are smaller than those described in previous work. Two new configurations of universal biquad filters based on these circuits are presented. A second-order bandpass filter, constructed using universal biquad filters, and a third-order Chebyshev lowpass filter, with 1 dB passband ripple, are breadboarded. Measured results are presented.

Novel oscillators using the operational transresistance amplifier

This paper introduces several novel active RC oscillator circuits using the operational transresistance amplifier (OTRA) as the basic active building block. A general configuration using a single OTRA is introduced, from which a minimum component oscillator is generated. Four new oscillator circuits based on using two OTRAs are reported. HSpice simulations to confirm the analysis are given.

CMOS operational transresistance amplifier for analog signal processing

A new CMOS realization of the Operational Transresistance Amplifier (OTRA) is introduced. The properties of the OTRA are shown to be suitable for VLSI applications employing MOS transistors operating in the ohmic region. Applications of the OTRA in realizing voltage amplifiers, multipliers, integrators, continuous time filters and a quadrature oscillator are presented. Voltage mode filters that benefit from the current processing capabilities at the input terminals of the OTRA are presented. A detailed analysis taking the effect of the finite transresistance gain into consideration is provided. Both passive compensation and self-compensation of the proposed circuits are presented. The effectiveness of the proposed circuits is demonstrated through PSpice simulations based on the AMI 1.2 μm N-well level 3 parameters.

ACTIVE RC FILTERS USING OPERATIONAL TRANSRESISTANCE AMPLIFIERS

A new generalized universal filter configuration using the Operational Transresistance Amplifier is proposed. Twelve different filter circuits are derived from the general configuration. The circuits are designed to provide Low-pass, Band-pass, High-pass, All-pass and Notch responses through appropriate choice of admittances. The feasibility of this configuration in operating at high frequencies is presented. A detailed analysis taking the effect of the finite transresistance gain into consideration is presented. Self-compensation that requires no additional elements of some of the proposed filters is presented. The effectiveness of the proposed configuration is demonstrated by HSpice simulations.

Single-capacitor MOSFET-C integrator using OTRA

A highly linear MOS operational transresistance amplifier (OTRA) integrator with reduced number of capacitors and MOSFET transistors is proposed. Only one capacitor is required for an integrator to achieve cancellation of MOSFET nonlinearities. The proposed integrator is insensitive to the effects of parasitic capacitances and can be interconnected without adding any buffers. Experimental results are given to verify the theoretical analysis.

Parasitic-capacitance-insensitive current-mode filters using operational transresistance amplifiers

A parasitic-capacitance-insensitive MOSFET-C integrator and differentiator using operational transresistance amplifiers are proposed and experimental results demonstrated. The bandwidths of these circuits are also independent of their gains. The required capacitances are smaller than those in previous work. Two new configurations of universal current-mode biquad filters based on these circuits are presented. A second-order bandpass filter constructed using universal biquad filters and another third-order Chebyshev lowpass filter with 0.1 dB passband ripple are breadboarded and the measured results presented.

Operational transresistance amplifier using CMOS technology

The Letter describes the design of a versatile analogue building block, termed an operational transresistance amplifer (OTRA). An operational transresistance amplifier has two low-input-impedance terminals and one low-output-impedance terminal. It is found to have a constant bandwidth indpendent of the gain in most closed-loop configurations. Simulation results are presented to demonstrate the constant-bandwidth performance. As an application example this amplifier is used to implement a MOSFET-C differentiator, of which analysis and simulation results are also presented.