Oguzhan Cicekoglu

Current-mode all-pass filters using current differencing buffered amplifier and a new high-Q bandpass filter configuration

A new configuration realizing first-order canonical current processing all-pass filters based on current differencing buffered amplifier, a recently introduced active element, is proposed. Using this configuration, two types of first-order current-mode all-pass filters are derived. They employ only a single active element and a bare minimum number of passive components. No component-matching constrains are required. Because of the high performance of the current differencing buffered amplifier, they are suitable for wideband applications. The derived filters are cascadable because of their high output impedances and they use fewer active and/or passive components compared to their previously reported counterparts. As an application of the proposed first-order all-pass networks, a new current-mode high-Q bandpass filter, which offers a number of advantages over its counterparts, is also given.

All-pass filters using a single current conveyor

Current conveyors are unity gain active elements exhibiting high linearity, wide dynamic range and better high frequency performance compared with their voltage mode counterparts. In this study a set of single positive-type second generation current conveyor based all-pass filters is presented and a catalogue of canonical topologies is given with some properties in tabular form. In contrast with single topology presentations, 22 different topologies are presented which exhibit identical transfer functions but differ in the number of passive components, component matching constraints, possibility of gain adjustment and other properties.

Current-Mode High Output Impedance Sinusoidal Oscillator Configuration Employing Single FTFN

In this study, a general current-mode high output impedance sinusoidal oscillator configuration is proposed. The proposed oscillator configuration uses a single four terminal floating nullor (FTFN), two capacitors and five resistors. The oscillator configuration exhibits high output impedance which makes easy to drive loads without using any buffering devices and provide non-interactive control of oscillation condition and oscillation frequency. The proposed topology also yields single frequency oscillators with reduced number of passive components. All of the proposed oscillators permit good frequency stability and exhibit low active and passive sensitivities. Theoretical analysis is verified with experimental results.

Novel allpass filter configuration employing single OTRA

A new circuit configuration uses a single operational transresistance amplifier (OTRA) and four passive elements to realize both first- and second-order allpass filters. Owing to internal grounding of the OTRA input terminals, effects of input parasitics are significantly reduced. Applications of the circuit include the realization of the phase equalizer, the quadrature oscillator, and the high-Q bandpass filter for analog signal processing. The performance of the allpass filter is illustrated by circuit-level simulation of a quadrature oscillator with CMOS realization of the OTRA.

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

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.

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.

A Resistorless realization of the first-order all-pass filter

All-pass filters are widely used to shift the phase of an analog signal without altering its magnitude. In this study, a new realization of all-pass filter using one current controlled conveyor (CCCII), one operational amplifier (OP-AMP) and two capacitors is presented. The proposed circuit does not use any resistors thus it is suitable for easy integration. Also the pole frequency of the proposed circuit can be tuned electronically. Simulation results are included to verify theory.

Electronically tunable, active only floating inductance simulation

In this paper a new floating inductance simulator employing only active elements is proposed. The proposed circuit uses one internally compensated operational amplifier and one dual output current controlled conveyor (CCCII). The simulated inductance value can be controlled electronically by adjusting the bias current of the CCCII. No component matching constraints are imposed for the simulator and all active sensitivities are low. The performance of the circuit is demonstrated on a fourth-order elliptic filter using a SPICE simulation program

Wide Dynamic Range High Output Impedance Current-mode Multifunction Filters with Dual-output Current Conveyors

Summary This paper reports five new single-input multiple-output current-mode multifunction filter circuits which can simultaneously realise three basic filter functions all at high impedance outputs. The circuits employ only the same type of active elements, grounded passive components, andno element matching conditions are imposed. The filters permit orthogonal adjustment of the quality factor Q and angular resonant frequency ω 0 . The active/passive sensitivities are shown to be low.