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

Abstract

Aparasitic-capacitance-insensitive MOS-FET-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 secondorder 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.

Realization of Fully Controllable Negative Inductance with Single Operational Transresistance Amplifier

“…The input terminals are internally grounded, leading to circuits that are insensitive to stray capacitances [5]. For ideal operation, the transresistance (R m ) approaches infinity, forcing the input currents to be equal.…”

“…The OTRA is commercially available from several manufacturers under the name of current differencing amplifier or Norton amplifier. Recently, it has gained considerable attention with the introduction of several high-performance complementary metal oxide semiconductor (CMOS) OTRA realizations that are simpler and more efficient than the one shown in Figure 1 [4], [5], [8], [10], [11]. …”

Third Order Universal Filter Using Single Operational Transresistance Amplifier

“…Higher order �lters can be obtained by various methods such as cascading lower order �lter or state variable method or signal �ow graph. Although OTRA based third order �lters are reported in the literature [17][18][19], they all involve more that one OTRA.…”

OTRA-based Grounded-FDNR and Grounded-Inductance Simulators and Their Applications

“…Although a large number of analog circuit building blocks have been considered as alternatives to the classical voltage-mode operational amplifier (VOA) which suffers from the limitations caused by the finite gain-bandwidth product and limited slew rates, the operational trans-resistance amplifiers (OTRA) [6,7,9] have been found to be particularly attractive in various analog signal processing/signal generation applications [1-5, 8, 10-17, 19-24] due to their following advantageous features: (i) transmission properties similar to the current-feedback op-amp (CFOA), (ii) elimination of slew rate limitations as encountered in VOAs and (iii) availability of two low-impedance inputs and one low-impedance output, which are advantageous for facilitating easy cascadability of OTRA-based circuits.…”