Current Controlled Conveyor Research Articles

Universal Biquadratic Filter Employing Single Differential Voltage Current Controlled Conveyor Transconductance Amplifier

This paper presents new realizations of second order voltage mode and current mode universal filters based on a recently reported active element, called the differential voltage current controlled conveyor transconductance amplifier (DVCCCTA). The proposed circuits do not use external resistor. The filter circuits provide all the responses without changing the circuit topology. All the capacitors are virtually grounded. The use of grounded capacitors makes the circuit suitable for monolithic implementation. The pole frequency and quality factor can be adjusted independently with the input bias currents. The non-ideal analysis and the sensitivity analysis have been included. Both the active and passive sensitivities are not more than unity. The filter performances are verified using the PSpice simulations which agree well with theoretical value. 

MIXED MODE UNIVERSAL FILTER

The configuration with electronic tunable characteristics that can work in mixed mode may be useful from IC realization viewpoint and application adaptability. This paper proposes an electronically tunable mixed mode universal filter based on multiple output current controlled current conveyor (MOCCCII) and this single topology without any alteration can be used in all four modes i.e., voltage (VM), current (CM), transimpedance (TIM) and transadmittance (TAM). The architecture uses four MOCCCIIs and two grounded capacitors; and can realize universal filter functions — low pass (LP), band pass (BP), high pass (HP), notch (NF) and all pass (AP) for all four modes. Moreover the input impedance is high and output impedance is low for voltage signal and vice-versa for current signal, hence the proposed topology is suitable for cascading for all four modes. The workability of the proposed circuit has been verified via SPICE simulations using AMS 0.35 μm CMOS technology.

An Active-Only Temperature-Insensitive Current-Mode Biquad Filter Based on Differentiator Structures Employing CCCCTAs

This article presents an active-only current-mode universal biquad filter performing three standard functions: low-pass, high-pass and band-pass function, which can be readily modified to achieve the rest functions (band-stop and all-pass). The circuit principle is based on active-only circuit designed by using differentiators which are constructed from current controlled current conveyor transconductance amplifier (CCCCTA) cooperating with an internally frequency compensated operational amplifier (OA). The features of the circuit are that: the pole frequency and quality factor can be independently tuned via the input bias currents and it is ideally temperature-insensitive, its circuit description is very simple, consisting of 3 CCCCTAs and 2 operational amplifiers, and the proposed circuit is very appropriate for further developing into integrated circuit architecture. The PSpice simulation results are shown. The given results agree well with the theoretical anticipation.

A FG-MOS Based Fully Differential Current Controlled Conveyor and Its Applications

This paper presents a new fully differential second generation current controlled conveyor (FDCCCII) based on differential pair topology, which employs floating gate MOS transistors (FG-MOS). It uses floating gate MOSFETs at the input stage and has rail-to-rail structure which performs with both positive and negative signals. This circuit has tunable parasitic resistance at its input port. It operates with low supply voltage (±0.8 V), low power consumption (lower than 3 mW at current bias of 1 mA), and wide range parasitic resistance (R X ). This circuit has less MOSFET than the previous similar circuits and is suitable for integrated circuit design. To demonstrate the application of the proposed circuit, a fully differential current mode LC-ladder filter and a fully differential multifunction biquad filter are designed. Simulation results by HSPICE confirm validity of the proposed circuit and its application.

DVCCCTA-Based Implementation of Mutually Coupled Circuit

This paper presents implementation of mutually coupled circuit using differential voltage current-controlled conveyor transconductance amplifier (DVCCCTA). It employs only two DVCCCTAs, one grounded resistor, and two grounded capacitors. The primary, secondary, and mutual inductances of the circuit can be independently controlled and tuned electronically. The effect of non-ideal behaviour of DVCCCTA on the proposed circuit is analyzed. The functionality of the proposed circuit is verified through SPICE simulation using 0.25 μm TSMC CMOS technology parameters.

Guest editorial: Introduction to the special issue on selected papers from the ELECO’2011 conference

Welcome to the Special Issue on Selected Papers from the ELECO-2011 Conference!, the seventh International Conference on Electrical and Electronics Engineering, held 1–4 December 2011, in Bursa-Turkey. ELECO conferences are organized at international level in odd numbered years and as national conferences in even numbered years. As such ELECO-2011 is the seventh international conference, with participants coming from various countries, presenting papers from the rich spectrum of electrical and electronics engineering discipline. ELECO-2011 is jointly organized by Uludag University, Bursa; Istanbul Technical University (ITU) and the Chamber of Turkish Electrical Engineers (EMO), Bursa Section. The IEEE-Turkey Section and The Scientific and Technological Research Council of Turkey (TUBITAK) are co-sponsors of ELECO-2011. We are grateful to them for their contributions. Considering the broad scope of the technical program, it was probably the largest electrical and electronics engineering conference ever held in Turkey. The scope of the conference covers topics ranging over electric power systems, electrical machines and drives, power electronics, high voltage techniques, electrical materials, electronics, circuits and systems, signal processing, electromagnetics, antennas and propagation, microwave theory, communication systems, mechatronics, control theory, control applications, automation systems, robotics and intelligent control systems. This year 288 papers have been submitted for presentation and 166 papers have been accepted. If we look at the contributions with respect to geographical point of view, it is seen that ELECO’2011 contributions are coming from 19 different countries. Selected papers from previous international ELECO Conferences were invited to be published in extended form in special ELECO issues of international journals, under peer review. Two special ELECO issues appeared in the journal Analog Integrated Circuits and Signal Processing containing selected papers from ELECO’2001 and ELECO’2007. Furthermore, four special ELECO issues appeared in the journal TJEECS: Turkish Journal of Electrical Engineering and Computer Sciences where selected papers from ELECO’2003, 2005, 2007 and 2009 were published in extended form, respectively. This Special Issue on Selected Papers from ELECO’2011 contains extended versions of ten papers presented at the conference. Two papers are selected from invited talks given by world-known scientists during the conference. The other eight are chosen from regular submitted manuscripts. The paper by Yahya Lakys and Alain Fabre entitled ‘‘Multistandard Transceivers: State of the Art and a New Versatile Implementation for Fully Active Frequency Agile Filters’’ was presented at ELECO-2011 as an invited paper. In this paper various architectures of transceivers for current standards are firstly compared, different possibilities to achieve multi-standard transceivers are also recalled and compared. It is demonstrated that the second generation current controlled conveyor operating in current mode is perfectly suitable for the realization of frequency-agile filters. A S. Ozoguz (&) H. H. Kuntman Faculty of Electrical Electronics Engineering, Istanbul Technical University, Maslak, 34469 Istanbul, Turkey e-mail: ozoguz@itu.edu.tr

Special type of three-phase oscillator using current gain control for amplitude stabilization

The main aim of this work is to demonstrate the use of electronically controlled second-generation current conveyor in providing electronic control to the condition of oscillation (CO) of a new active RC sinusoidal oscillator. Electronic control of the CO, which is independently set and does not affect the oscillation frequency, is enabled by the use of an auxiliary amplitude control loop to regulate the amplitude and provide very good total harmonic distortion performance. The proposed oscillator employs only one standard second-generation current conveyor, one electronically controlled second-generation current conveyor, five passive elements and is capable of providing three voltage outputs having phase shifts 45 and 90°, if specific design requirements are fulfilled. Similar simple types of oscillators do not provide such features. Non-ideal analysis of the circuit has also been carried out and the proposed oscillator has been verified by both PSpice simulations and experimental measurements using commercially available integrated circuits. Key words: Three-phase oscillator, special features, electronic control, electronically controllable current conveyor (ECCII), second generation current conveyor (CCII).

Multistandard transceivers: state of the art and a new versatile implementation for fully active frequency agile filters

The various architectures of transceivers for current standards are firstly compared. Different possibilities to achieve multi-standard transceivers are also recalled and compared. We demonstrate that ease of realization and flexibility evolve in opposite directions. The advantages and drawbacks of reconfigurable active filters are indicated. We demonstrate that the second generation current controlled conveyor operating in current mode is perfectly suitable for the realization of frequency-agile filters. After a brief recall of the essential points of agile filters, a second order frequency agile bandpass filter operating in current mode is implemented with CCCII+. It has four central frequencies whose values could be selected digitally. The validation results show that its tuning ratio n = f 0max /f 0min is equal to 5.1 with f 0max = 1.22GHz.

Current controlled current differential current conveyor: a novel building block for analog signal processing

In this paper, a novel active block for analog signal processing is presented, namely the current controlled current differential current conveyor (CCCDCC). This multi terminal block has most features of the well-known CCII (Second Generation Current Conveyor) and CCCDTA (Current Controlled Current Differencing Tranconductance Amplifier) to simplify the realization of current-mode analog filters suitable for signal processing. The proposed block and its applications were simulated in 0.18µm CMOS process at ±0.9V supply voltages. All of results were obtained by Hspice and with a high detailed transistor library.

A New Current-Mode Universal Filter with Single-Input Five-Output Using Trans-Linear Current Conveyors

This paper presents a new current-mode current-controlled one-input five-output universal filter, employing only three trans-linear current conveyors and two grounded capacitors. The proposed configuration provides low-pass, band-pass, high-pass, band-stop and all-pass current responses. It exhibits low-input and high-output impedances, which is highly desirable for cascading in current-mode. Also, it offers the advantage feature of an independent electronic control of the natural frequency (ω J and the quality factor (Q) through tuning the external bias currents. Moreover, a high Q-value filter can be obtained by separately adjusting the appropriate current gain of CCCII (second-generation current controlled conveyor). The active and passive sensitivities of the filter are low. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theoretical analysis.

Voltage- and current-controlled high CMRR instrumentation amplifier using CMOS current conveyors

A new approach to the design of an instrumentation amplifier using only 2 CMOS current-controlled conveyors and an active resistor is introduced. The new approach, which has no passive components, offers a wide bandwidth and a high common-mode rejection ratio (CMRR). Electronically controllable gain by voltage and current is also obtained by this new circuit. The circuit is simulated using the parameters of a 0.35-\mu m TSMC CMOS technology. Theoretical analysis of the circuits was carried out, and the performance of the block circuit was confirmed through PSpice simulation results.

Single MO-CCCCTA-Based Electronically Tunable Current/Trans-Impedance-Mode Biquad Universal Filter

This paper presents an electronically tunable current/trans-impedance-mode biquad universal filter employing only single multi-output current controlled current conveyor trans-conductance amplifier (MO-CCCCTA) and two grounded capacitors. The proposed filter realizes all the standard filter func-tions i.e. low pass (LP), band pass (BP) and high pass (HP), notch and all pass (AP) filters in the current form at high impedance output through appropriate selection of the input signals, without any matching conditions. Simultaneously, it can also realize all the standard filter functions in trans-impedance form from the same circuit topology. The circuit does not require inverting-type input current signal(s) and double input current signal(s) to realize all the responses in the design. The validity of proposed filter is verified through PSPICE simulations.

Cognitive and encrypted communications: state of the art and a new approach for frequency-agile filters

Several communication techniques are investigated in the first part of this paper: software radio, cognitive radio and encrypted communications. State of the art of research on agile and reconfigurable filters, passive as well as active, necessary for transceivers is then made and various tables for comparison are given. In the third part, a new theory for a 2^{nd}-order frequency-agile filter is introduced. The center frequency of the filter is proportional to the gain of a feedback amplifier and thus can be tuned over a wide frequency range. This new theory is thereafter generalized to the n^{th}-class leading to a center frequency proportional to (A)^{n/2}. Simulation results of band pass agile filters in current mode and made from second-generation current controlled conveyors (CCCII+) in 0.25 \mu m SiGe BiCMOS technology are given for n = 1 and n = 2. These simulation results along with results of measurements carried out on the fabricated filters entirely confirm the new approach. They also highlight the improvements to be expected for cognitive and encrypted communications.

Electronically tunable low-voltage mixed-mode universal biquad filter

This study presents an electronically tunable low-voltage mixed-mode universal biquad filter. The proposed filter employs only three current controlled current conveyor trans-conductance amplifiers (CCCCTAs) and two grounded capacitors. The proposed filter can realise low pass, band pass and high pass responses in all the four possible modes, that is, voltage-mode, current-mode, trans-admittance-mode and trans-impedance-mode from the same configuration. The filter can also realise regular notch, low-pass notch, high-pass notch and all pass responses in current and trans-admittance-mode, with interconnection of relevant output currents. The filter parameters namely pole frequency, quality factor, bandwidth and filter gains can be tuned electronically. Moreover, the circuit parameters such as pole frequency and quality factor can be simultaneously current controlled without affecting bandwidth. Effects of non-idealities and parasitic are also discussed. The circuit possesses low active and passive sensitivity and can be operated at low power supply (±1 V). The validity of the proposed filter is verified through computer simulations using PSPICE, the industry standard tool. Possible experimental setup for CCCCTA using commercial available integrated circuits is further discussed.

Nth Order Voltage Mode Active-C Filter Employing Current Controlled Current Conveyor

This paper proposes an nth order (where n = 2,3, ,n) voltage mode active-C filter using n number of current controlled current conveyors (CCCIIs) and n number of equal valued grounded capacitors. The proposed topology can implement both band pass and low pass responses without alteration of any components. The filters offer the following important features: use of minimum number of current controlled current conveyors (CCCIIs) and passive components, no matching constraint, use of all grounded capacitors and absence of external resistor suitable for integration, cut off frequency can easily be electronically adjusted using AMS 0.35 µm CMOS technology. PSPICE simulation results of third order band pass and low pass responses are provided. The results are found to agree well with the theory.

High Frequency Oscillator Design Using a Single 45 nm CMOS Current Controlled Current Conveyor (CCCII+) with Minimum Passive Components

In the field of analog VLSI design, current conveyors have reasonably established their identity as an important circuit design element. In the literature published during the past few years, numerous application have been reported which are based on a variety of current conveyors. In this paper, an oscillator circuit has been proposed. This oscillator is designed using a single positive type second generation current controlled current conveyor (CCCII+). A CCCII has parasitic input resistance on it’s current input node. This resistance could be exploited to reduce circuit complexities. Thus in this accord, a novel oscillator circuit is proposed which utilizes the parasitic resistance of the CCCII+ along with a few more passive components.

Resistorless dual-mode quadrature sinusoidal oscillator using a single active building block

This paper presents a new realization of resistorless mixed-mode (i.e. both voltage-mode and current-mode) quadrature sinusoidal oscillator using a new active building block (ABB) called the differential voltage current-controlled conveyor transconductance amplifier (DVCCCTA). The proposed oscillator circuit uses a single DVCCCTA, two grounded capacitors (GCs) and does not employ any external linear resistors. The tuning laws for the condition of oscillation (CO) and the frequency of oscillation (FO) are non-interactive; and controlled by separate bias currents. The circuit provides two explicit quadrature current outputs and two quadrature voltage outputs and thus can be classified as a mixed-mode quadrature oscillator. Another notable feature of the proposed circuit is that it can also be used as a biquadratic filter to realize low-pass and band-pass filtering functions simultaneously. Non-ideal analysis of the circuit is provided and PSpice simulation results have been included to verify the workability of the proposed circuit.

SIMO Transadmittance Mode Active-C Universal Filter

This paper presents two transadmittance mode universal filters having single voltage input and multiple current outputs. The filter employs three multiple output current controlled conveyors (MOCCCII) and two grounded capacitors. It can realize low pass, high pass, band pass, notch and all pass responses. As desired, the input voltage signal is inserted at high impedance input terminal and the output currents are obtained at high impedance output terminals and hence eases cascadability. The filter enjoys low sensitivity performance and low component spread; and exhibits electronic and orthogonal tunability of filter parameters via bias currents of MOCCCII. SPICE simulation results confirm the workability of the proposed structure.

Low-voltage current controlled current conveyor

A novel second-generation Current Controlled Current Conveyor (CCCII) topology is introduced in this paper. Compared with the corresponding already introduced topologies, the proposed CCCII offers the advantage of low-voltage operation capability. In addition, due to the absence of PNP or PMOS transistors for handling ac signals, its performance in terms of maximum frequency of operation is improved.

Design of tunable biquadratic filters employing CCCIIs: state variable block diagram approach

A state variable block diagram method is given for the realization of universal biquadratic transfer functions employing second-generation current-controlled conveyors (CCCIIs). Using minimum number of passive components and properly adjusting the bias currents of CCCIIs, the proposed circuits can realize all the tunable frequency standard filter functions: high-pass, band-pass, low-pass, notch-pass, and all-pass by choosing appropriate input branches without changing the passive elements. These presented circuits are in current-mode and voltage-mode separately. The non-ideality analyses of these configurations are given. Additionally, a high-order low-pass filter derived from the proposed voltage-mode biquadratic filter is introduced. PSPICE simulation results are included to verify the theory.