Sadri Özcan

Single resistance-controlled sinusoidal oscillators employing current differencing buffered amplifier

Abstract The basic aim of this paper is to present several of a newly introduced current differencing buffered amplifier (CDBA)-based oscillator topologies achieving orthogonal control of oscillation condition b and oscillation frequency ω 0 with a reduced number of components. A single resistor is used for adjusting their frequency, and further, this resistance is grounded, which is important from the integration point of view. Taking these considerations into account they are very suitable for voltage-controlled oscillator (VCO) implementation.

High-output-impedance transadmittance type continuous-time multifunction filter with minimum active elements

A new transadmittance multifunction filter with single input and three outputs employing only three positive-type second-generation current conveyors and five passive elements is presented. The proposed filter realizes three basic filter functions simultaneously, all at high impedance outputs. No component matching is required and all the passive sensitivities are low. Experimental verification is also performed.

Multi-input single-output filter with reduced number of passive elements employing single current conveyor

Abstract A new biquadratic universal filter configuration realising second-order low-pass, band-pass, and high-pass functions employing single current conveyor is proposed. Using this configuration high-pass, low-pass and band-pass filters can be realized with little modifications. The circuit employs a second-generation current conveyor (CCII+), and only four passive components. Since the current conveyor is a high performance active element, the circuit proposed is suitable for wide band applications. The derived filters can be easily cascaded and use reduced number of passive components compared to previously reported counterparts. To illustrate the design possibilities provided by the introduced circuit current mode multifunction filters are constructed and tested.

Realization of Current-Mode Third Order Butterworth Filters Employing Equal Valued Passive Elements and Unity Gain Buffers

This paper describes current-mode third-order Butterworth filter topologies realized with unity gain active elements and minimum number of passive components. All capacitors and resistors are equal valued. The core of the circuit realizes HP, BP and LP functions easily. The filter exhibits high output impedance. Experimental results are included to verify theory.

A novel multi-input single-output filter with reduced number of passive elements using single current conveyor

A new biquadratic universal filter configuration realizing second-order low-pass, band-pass, and high-pass filters using a single current conveyor is proposed. Using this configuration high-pass, low-pass and band-pass filters can be realized with little modifications. The circuit employs a second-generation current conveyor (CCII+), and only four passive components. Since the current conveyor is a high performance active element, the circuit proposed is suitable for wide band applications. The derived filters can be easily cascaded and use reduced number of passive components compared to previously reported counterparts. To illustrate the design possibilities provided by the introduced circuit, current mode multifunction filters are constructed and tested.

Insensitive Multifunction Filter Implemented with Current Conveyors and only Grounded Passive Elements

The paper presents a new multifunction filter which can simultaneously realise low-pass, high-pass and band-pass functions. The circuit employs only positive-type second generation current conveyors, grounded passive components and exhibits high input impedance. No element matching conditions are imposed. The filter permits orthogonal adjustment of quality factor Q and ω 0 . For one possible set of component selection the filter permits compensation for the parasitics. The passive sensitivities are shown to be low.

High output impedance current-mode third-order Butterworth filter topologies employing unity gain voltage buffers and equal-valued passive components

This paper presents eight new current mode third-order band pass filter topologies employing unity-gain active elements, three resistances and three capacitors. An additional topology is identical to a previously reported one, repeated here for completeness. Using equal passive components, all of the proposed topologies realize third-order BP Butterworth filter function, which can easily be converted to a LP if they are cascaded with an integrator, Therefore, without any component spread the circuits are attractive from the integration point of view. In each of the circuits, except one topology, one of the unity gain cells can be replaced by a second-generation current conveyor to pick up the output current and to obtain a high impedance output. The high output impedance provided by the current conveyor permits easy cascadability for the proposed circuits to construct high-order communication filters. Simulation and experimental results are included to verify theory.

New active-only grounded inductance simulator employing current-mode approach suitable for wide band operation

In this paper, an active-only grounded lossless inductance simulator operating in current-mode is presented. The circuit uses only a current operational amplifier (COA) and an operational transconductance amplifier (OTA). The novelty of the proposed circuit is that it uses a COA instead of a voltage operational amplifier (VOA) to take the wider frequency operation advantage of the current-mode approach. The simulation results obtained through SPICE with 0.5 μm standard CMOS technology verify that the designed circuit can be operated up to 30 MHz, which is much higher than the operation frequency of previously reported inductance simulators utilising VOAs. The inductance value of the presented circuit can be adjusted electronically between 3.9 μH and 37 μH via the biasing current of the OTA. A parallel resonance circuit application is also given validating the operation of the proposed inductance simulator.

Electronically tunable inductance simulator employing dual-X current conveyors (DXCCIIs)

In this study, an electronically tunable inductance simulator employing only two Dual-X Current Conveyors (DXCCIIs) as active building blocks is presented. The proposed circuit can be used in the frequency range from 1kHz to 1MHz and consumes only up to 20mW/Proposed circuit is simulated with SPICE using 0.5Pm Mietec process parameters. Simulation results demonstrate the versatility of the newly introduced inductance simulator.

Realization of inductorless RF bandpass amplifiers using immittance simulators employing CCIIs

The use of circuits constructed with current conveyors has been demonstrated to be potentially advantageous for the realization of high frequency continuous-time monolithic analogue systems. This paper presents the realization of inductorless bandpass amplifiers suitable for RF applications using immittance simulators employing CCIIs. A design example of fourth order flat-band amplifier is given and the performance of the circuit is demonstrated by comparing the theory and experiment.