Erkan Yuce

A Modified CFOA and Its Applications to Simulated Inductors, Capacitance Multipliers, and Analog Filters

In this paper, using a minimum number of passive components, i.e., new grounded and floating inductance simulators, grounded capacitance multipliers, and frequency-dependent negative resistors (FDNRs) based on one/two modified current-feedback operational amplifiers (MCFOAs), are proposed. The type of the simulators depends on the passive element selection used in the structure of the circuit without requiring critical active and passive component-matching conditions and/or cancellation constraints. In order to show the flexibility of the proposed MCFOA, a single-input three-output (SITO) voltage-mode (VM) filter, two three-input single-output (TISO) VM filters, and an SITO current-mode (CM) filter employing a single MCFOA are reported. The layout of the proposed MCFOA is also given. A number of simulations using the SPICE program and some experimental tests are performed to exhibit the performance of the introduced structures.

Novel Voltage-Mode All-Pass Filter Based on Using DVCCs

In this paper, a novel design for realizing a voltage-mode (VM) all-pass filter utilizing two differential voltage current conveyors (DVCCs) is proposed. Also, the suggested filter uses a canonical number of passive elements (one grounded capacitor and one resistor) without requiring any element matching condition. The proposed filter has high input and low output impedances, which make it suitable for cascading. The effects of the nonidealities of the DVCCs on the proposed design are investigated. As an application, a quadrature oscillator is designed using the proposed VM all-pass filter and an integrator. The proposed filter and oscillator circuits are simulated using the SPICE simulation program to confirm the theory.

Limitations of the Simulated Inductors Based on a Single Current Conveyor

In this paper, a new simulated inductor employing two resistors, one capacitor, and only a single gain-variable third-generation current conveyor (GVCCIII) is proposed. To exhibit the performance of the proposed simulated inductor, it is used in a parallel R-L-C current-mode filter. The frequency-dependent nonideal voltage gain effects of the GVCCIII on the proposed inductor are given. The low- and high-frequency limitations of the simulated inductor are investigated in detail. The simulations performed with the SPICE program agree with the theoretical analysis. Also, the proposed circuit is tested experimentally using commercially available active devices (AD844 ICs of Analog Devices) to confirm the theory

Full-wave rectifier realization using only two CCII+s and NMOS transistors

In this paper, a voltage-mode full-wave rectifier employing plus-type second-generation current conveyors (CCII+s) and enhancement-mode n-channel metal-oxide semiconductor field-effect transistors (MOSFETs) is proposed. The presented circuit requires no passive components, and is suitable for high frequency applications. The proposed full-wave rectifier circuit is simulated using HSPICE to verify the theoretical analysis.

All-Grounded Passive Elements Voltage-Mode DVCC-Based Universal Filters

In this paper two new voltage-mode (VM) universal filters employing three plus-type differential voltage current conveyors (DVCC+s) and grounded passive elements are presented. The first proposed filter is a single-input five-output (SIFO) circuit which can realize simultaneously all of the standard responses, i.e. low-pass (LP), band-pass (BP), high-pass (HP), all-pass (AP) and notch (NH) from the same configuration. The second proposed circuit is a three-input single-output (TISO) universal filter for realizing standard responses depending on the selection of the input signal from the same topology. Both of the proposed filters have the advantage of a high input impedance, which enables easy cascading to obtain higher order filters. The proposed filters are simulated using the SPICE program to verify the theoretical analysis.

A new full-wave rectifier circuit employing single dual-X current conveyor

In this study, a novel voltage-mode full-wave rectifier with high-input impedance using a dual-X second-generation current conveyor and three enhancement-type n-channel metal-oxide semiconductor field-effect transistors (MOSFETs) is introduced. The proposed circuit does not employ any passive elements, and is simulated using SPICE program with level 49, 0.25 µm TSMC CMOS technology parameters to confirm the theory and exhibit the performance of the circuit.

A Simple Schmitt Trigger Circuit with Grounded Passive Elements and Its Application to Square/Triangular Wave Generator

This paper introduces a new simple Schmitt trigger circuit using a plus-type differential voltage-current conveyor (DVCC+) and only two grounded resistors. The proposed circuit is very simple and enjoys adjustable lower and higher threshold voltages as well as the output saturation levels. The application of the proposed Schmitt trigger circuit to the square/triangular wave generator is also given. Moreover, a current feedback operational amplifier (CFOA)-based square/triangular wave generator is derived from the proposed DVCC+-based circuit. Simulation and experimental results are presented to exhibit the performance of the proposed circuits.

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.

Grounded Inductor Simulators With Improved Low-Frequency Performances

In this paper, the nonideality effects such as non-ideal gain and parasitic-impedance effects on the low-frequency performance of two new grounded inductor simulators are investigated in great depth. In addition, some low-frequency-performance improvement methods for grounded inductor simulators are discussed. Both of the grounded simulated inductors derived from the previously published ones employ a minimum number of grounded passive components and plus-type second-generation current conveyors. Four second-order voltage-mode universal-filter topologies, three of which are novel, are derived from newly and previously developed simulated inductors as application examples. Computer simulations with SPICE program including ideal and experimental test results are drawn to verify theoretical ones.

On the realization of high-order current-mode filter employing current controlled conveyors

In this paper, a general structure for realizing high-order current-mode analog filter responses with single-input and three-outputs is presented. The proposed circuit uses dual-output second-generation current controlled conveyors (DO-CCCIIs) and only grounded capacitors (Active-C structure), and can simultaneously realize low-pass, band-pass (if order is even number) and high-pass filter responses. The developed circuit does not require any component matching constraints thus it is suitable for fully integrated circuit (IC) technology. Simulations are performed for the fourth-order Butterworth filter to illustrate the frequency domain performance of the circuit.