Current Controlled Conveyor Research Articles

Simple CMOS voltage differencing current conveyor‐based electronically tunable quadrature oscillator

A brief example of application of recently introduced concept of electronically controllable CMOS voltage differencing current conveyor of second generation in electronically tunable second-order oscillator is shown. On-chip experimental results confirm theory and design intentions.

Simple Oscillator with Enlarged Tunability Range Based on ECCII and VGA Utilizing Commercially Available Analog Multiplier

Abstract This work presents an example of implementation of electronically controllable features to an originally unsuitable circuit structure of oscillator. Basic structure does not allow any electronic control and has mutually dependent condition of oscillation (CO) and frequency of oscillation (FO) if only values of passive elements are considered as the only way of control. Utilization of electronically controllable current conveyor of second generation (ECCII) brings control of CO independent of FO. Additional application of voltage amplifier with variable gain in both polarities (voltage-mode multiplier) to feedback loop allows also important enlargement of the range of the independent FO control. Moreover, our proposal was tested and confirmed experimentally with commercially available active elements (“Diamond transistor”, current-mode multiplier, voltage-mode multiplier) in working range of tens of MHz.

A First-Order Fully Cascadable Current-Mode Universal Filter Composed of Dual Output CCIIs and a Grounded Capacitor

In this paper, a new first-order current-mode (CM) universal filter employing two dual output second-generation current conveyors (DO-CCIIs), one resistor and a grounded capacitor is proposed. The proposed filter has low input and high output impedances; thus, it can be easily connected with other CM circuits. It can simultaneously realize first-order low-pass (LP) and all-pass (AP) responses and can provide high-pass (HP) response with interconnection of LP and AP responses. It can be tuned electronically by replacing with dual output second-generation current controlled conveyors (DO-CCCIIs) instead of DO-CCIIs and removing the resistor. It has only a resistor but no capacitor connected in series to X terminal of DO-CCII; accordingly, it can be operated at high frequencies. Also, it does not need any critical passive component matching conditions and cancellation constraints. A number of simulation results based on SPICE program are included to exhibit performance, workability and effectiveness of the proposed filter configuration.

New Current-Mode Class 1 Frequency-Agile Filter for Multi Protocol GPS Application

Recently, due to their cost, accuracy, and integrability of conventional current-mode (CM) on-chip integrated filters working in radio frequency region, frequency-agile filters (FAFs) have started taking great interest in multi-standard transceivers, encrypted communication, cognitive radio, software defined radio structures, and global positioning system applications. By following the most recent trend in the literature, this paper proposes the first class 1 CM FAF using high-performance analog building block so-called positive-type electronically controllable second-generation current conveyor (ECCII+), two resistors, and two grounded capacitors. The theory and the proposed 2nd-order CM FAF are supported by both regular and post-layout simulations performed using CADENCE Spectre tool with TSMC 0.18 µm level-49 CMOS technology process BSIM3v3 parameters. Furthermore, corner and Monte-Carlo analyses are given to prove the accuracy of centre frequency of the CM FAF. DOI: http://dx.doi.org/10.5755/j01.eee.21.5.13323

Systematic synthesis of CCCCTA-based T-T filters using NAM expansion method

ABSTRACTIn the light of nullor-mirror models for current-controlled current conveyor trans-conductance amplifier (CCCCTA), initiating the admittance matrices of the Tow-Thomas (T-T) filter, three different types of the T-T filter are synthesised by means of the nodal admittance matrix (NAM) expansion method. The type A filter, which employ one CCCCTA, one grounded resistor and two grounded capacitors, has eight different forms, the type B filter, which employ one CCCCTA, two grounded capacitors and a second-generation current-controlled conveyor (CCCII) or an second-generation inverting current-controlled conveyor (ICCCII) or an operational trans-conductance amplifier (OTA), has 64 different forms and the type C filter employing one CCCCTA and two grounded capacitors has eight different forms. In all, 80 voltage-mode/current-mode T-T filter circuits are obtained. Because of using canonic number components, the circuits are highly desirable from the viewpoint of IC fabrication and their parameters can be electronically tuned through tuning bias currents of CCCCTAs. The hand analysis and computer simulation results have been provided to support the synthesis method.

On the Realization of CMOS Current-Controlled Current Conveyor Transconductance Amplifier (CCCCTA) with Linear Control of g<sub>m</sub>

In this paper, arealizationcurrent controlled current conveyor transconductance amplifier (CCCCTA)is presented astheactiveelement.Thisdesignwas based on aCMOStechnology of AMIS 0.35μm (MOSIS).The PSPICE simulation was used to study the performances of the proposed circuit. It was found that the abilities of differential-pair CCCII circuit and Electronically current-tunable (EOTA) can be achieved using the supply voltages of ±1.5volts and the transconductance gain of the circuit can be linearly tuned.

Comparison of Two Solutions of Quadrature Oscillators With Linear Control of Frequency of Oscillation Employing Modern Commercially Available Devices

This paper proposes two circuits of frequency-controlled oscillators, whose structures are based only on simple commercially available active elements with minimum number of terminals, in particular, the differential voltage buffer, controllable voltage amplifier and electronically controllable current conveyor. Two methods for achieving linear control (tuning) of frequency of oscillations (FO) are discussed. The first method employs a simple structure. However, the generated signal level (amplitude) depends on the tuning process. This is a drawback of this method. The second method solves this drawback completely, and the generated signals have constant amplitudes during the tuning of FO. The expected behavior is confirmed by laboratory experiments utilizing commercially available high-speed active elements (current- and voltage-mode multipliers, video difference amplifier). Operational range was tested from frequencies of hundreds of kHz up to frequencies of tens of MHz.

Current Mode Universal Filter Using Single Current Controlled Differential Difference Current Conveyor Transconductance Amplifier

This research paper contains a new electronically tunable current-mode biquadratic universal filter using a new active building block; current controlled differential difference current conveyor transconductance amplifier (CCDDCCTA). The proposed filter provides the following important and desirable features: (i) One can use only one CCDDCCTA and two capacitors; (ii) One can get low pass (LP), band pass (BP), high pass (HP), notch (NF) and all pass (AP) current responses from the same configuration without any alteration; (iii) Passive components are grounded, which ease the integrated circuit implementation; (iv) Responses are electronically tunable; and (v) Sensitivity is low. Moreover, the non-ideality analysis shows that the parasitic passive components can be compensated for the proposed circuit. The functionality of the design is verified through SPICE simulations using 0.25 μm CMOS TSMC technology process parameters. Simulation result agrees well with the theoretical analysis.

NAM expansion method for systematic synthesis of floating gyrators using CCCCTAs

This paper presents a nodal admittance matrix expansion method for systematically synthesizing floating gyrators using current controlled current conveyor transconductance amplifiers (CCCCTAs). After describing nullor---mirror models of the CCCCTAs, class I and II gyrators are synthesized by means of NAM expansion method. The class I gyrators employing a CCCCTA and a current-controlled current conveyor have 16 equivalent realizations, and the class II gyrators employing two CCCCTAs have 24 equivalent realizations. Having used canonic number of components, the circuits are easy to be integrated and their parameters can be electronically tuned through tuning bias currents of CCCCTAs. Finally, as an example, the MULTISIM simulation results of a notch filter constructed by using a class II gyrator are presented to verify the realizability of the derived circuits.

Current-tunable current-mode RMS detector

A new realization of root mean square (RMS) detector comprising two controlled current conveyors, metal-oxide-semiconductor transistors and a single grounded capacitor is presented in this paper, without any external resistors and components matching requirements added. The proposed circuit can be used for measuring the RMS value of periodic, band-limited signals. Inherently, the circuit is well suited for IC implementation. The errors related to signal processing and errors bound were investigated and provided. To verify the theoretical analysis, the circuit PSpice simulations have also been included, showing good agreement with the theory. The maximum power consumption of the converter is \(\sim \)4.28 mW, at \(\pm \)1.25 V supply voltages.

Third-order voltage-mode active-C band pass filter

In this research article, a new third-order voltage-mode active-C asymmetrical band pass filter is proposed. It uses three numbers of current-controlled current conveyors and three numbers of equal-valued capacitors. The topology has the following important features: uses only three active elements, uses three capacitors, uses all grounded capacitors and no resistor is suitable for integrated circuit design, there is no matching constraint, high input impedance, low output impedance, central frequency can easily be electronically controlled by bias current, and frequency response is asymmetrical in nature. The application of the proposed topology in the realisation of a voltage-mode sixth-order symmetrical band pass filter has been demonstrated. The workability of the proposed topology and sixth-order filter has been confirmed by simulation results using 0.35-µm Austria Micro Systems complementary metal oxide semiconductor technology.

16NM BULK CMOS DOCCCII BASED CONFIGURABLE ANALOG BLOCK DESIGN FOR FIELD PROGRAMMABLE ANALOG ARRAY

Field programmable analog array (FPAA) is a rapidly growing technology for fast prototyping of analog signal processing systems facilitating the quick innovation at industry level with saving in terms of both time and cost. Analog signal processing is much faster and consumes less power than conventional digital signal processing, justifying the need for FPAA. Here we propose a Dual output current controlled current conveyor (DOCCCII) in 16nm bulk CMOS technology using PTM (High Performance 16nm Metal Gate / High-K / Strained-Si parameter) and discuss its characteristic. DOCCCII is superior in design among Current Conveyors because it requires no additional resistance for activation, it has it’s own parasitic resistance tunable through biasing current and has high bandwidth (GHz range). A configurable analog block (CAB) is also proposed which mainly consists of the DOCCCII readily configurable to realize an application. This cab is used here for the realization of 2 nd order filters.

Ameliorated Structure of Current Controlled Conveyor [CCCII] and it's Performance Analysis

This paper deals with multiple output current controlled conveyor [MOCCC] and a new structure of “Second generation Current Controlled Conveyor [CCCII]” is also presented which is known as ameliorated structure of CCCII. This paper also deals with the performance analysis of ameliorated CCCII over conventional Current Conveyor. With new structure of CCCII both static and dynamic performances are improved. Thanks to an objective function which maximizes current bandwidth of new CCCII. The ameliorated structure presents current bandwidth of 46.878MHz as compared to 10.771MHz for conventional CCCII. A Pspice simulation using bipolar technology with Q2N2222 for NPN and Q2N2907 for PNP transistor models is presented which demonstrate the results. Keyword, Ameliorated structure of CCCII.

Low-voltage low-power multifunction current-controlled conveyor

In this study, low-voltage low-power multifunction current-controlled conveyor (CCCII) is introduced. Multifunction current conveyors are able to achieve various CCCII structures with a small modification in the circuit. The proposed circuit required ±0.5 V as a power supply, a simple circuit structure and low power consumption. The power consumption is only 4.8 µW. Low-voltage operation is achieved by using changeable threshold voltage and PMOS level-shifter current mirror. This circuit is able to operate as CCCII± with both positive and negative intrinsic resistance, which have a wide tunable range with a small modification in the circuit connections.

Simple BiCMOS CCCTA design and resistorless analog function realization.

The simple realization of the current-controlled conveyor transconductance amplifier (CCCTA) in BiCMOS technology is introduced. The proposed BiCMOS CCCTA realization is based on the use of differential pair and basic current mirror, which results in simple structure. Its characteristics, that is, parasitic resistance (R x) and current transfer (i o/i z), are also tunable electronically by external bias currents. The realized circuit is suitable for fabrication using standard 0.35 μm BiCMOS technology. Some simple and compact resistorless applications employing the proposed CCCTA as active elements are also suggested, which show that their circuit characteristics with electronic controllability are obtained. PSPICE simulation results demonstrating the circuit behaviors and confirming the theoretical analysis are performed.

New systematic two‐graph‐based approach of active filters employing multiple output current controlled conveyors

A new method for the synthesis of active RC circuits employing multiple output current controlled conveyors (Mo-CCCIIs) is presented here. A new graph is proposed for Mo-CCCII and the application of this graph in active filter design is studied. The obtained active filter uses Mo-CCCIIs as active devices and only capacitors as passive elements without the need of passive resistors. To generalise the proposed method, an algorithm is presented, which converts the loop–cut-set matrices of the passive LC filter prototypes to the proper matrices for Mo-CCCII-based active filters. The new matrices characterise the connections of the equivalent Mo-CCCII-based active filter. The presented algorithm is programmed in MATLAB, so the matrix manipulation is done very quickly. Also, Hspice simulation result of the synthesised active filter is given to confirm the viability of this approach.

Differential voltage current controlled current conveyor with low-voltage operation capability

A novel differential voltage current controlled current conveyor topology is introduced in this article. It has the capability for operating in a low-voltage power supply environment and, also, offers resistorless filter realisations. The main attractive offered benefit is that the handling of AC signals is exclusively performed by nMOS transistors and, thus, the proposed element has capability for high-frequency operation. The performance of the proposed cell has been experimentally verified through the realisation of two 3rd-order filters, derived according to the leapfrog and component substitution methods. The filter topologies have been fabricated through the AMS 0.35 µm CMOS process.

Electronically tunable mutually coupled circuit using only two active components

A new circuit for realisation of the mutually coupled circuit, which is also called the synthetic transformer, is proposed. The proposed circuit uses two current controlled current conveyor transconductance amplifiers (CC-CCTAs), one grounded resistor and two grounded capacitors. The primary self-inductance, the secondary self-inductance and the mutual inductance can be independently controlled and can be tuned electronically by changing the biasing current of the CC-CCTAs. It uses two grounded capacitors which are suitable from the point of integrated circuit implementation. It has a good sensitivity performance with respect to tracking errors and passive components. The validity of the proposed circuit is demonstrated by PSpice simulations.

Current Controlled Differential Difference Current Conveyor Transconductance Amplifier and Its Application as Wave Active Filter

This paper proposes current controlled differential difference current conveyor transconductance amplifier (CCDDCCTA), a new active building block for analog signal processing. The functionality of the proposed block is verified via SPICE simulations using 0.25 μm TSMC CMOS technology parameters. The usefulness of the proposed element is demonstrated through an application, namely, wave filter. The CCDDCCTA-based wave equivalents are developed which use grounded capacitors and do not employ any resistors. The flexibility of terminal characteristics is utilized to suggest an alternate wave equivalents realization scheme which results in compact realization of wave filter. The feasibility of CCDDCCTA-based wave active filter is confirmed through simulation of a third-order Butterworth filter. The filter cutoff frequency can be tuned electronically via bias current.

Design centering/yield optimization of power aware band pass filter based on CMOS current controlled current conveyor (CCCII+)

Process variability are getting worse with the scaled technologies especially below 90nm, therefore for the reliable fabrication outcome, the effect of both the local and global process variability should be taken into account. In this paper, verification, sizing and design centering/yield optimization for the robust second generation current controlled current conveyor (CCCII+) and CCCII+ based band pass filter for low power without degrading other performances values have been presented. Current conveyors (CC) based applications are getting significant attention in current analog ICs design due to their higher band-width, greater linearity, larger dynamic range, simpler circuitry, lower power consumption. Moreover CCCII has the advantage of electronic tunability at its intrinsic resistance terminal via a bias current. The net lists of CCCII+ and band pass filter circuits have been simulated in Eldo using the 65nm CMOS mixed signal low-K TSMC process development kit (PDK) with 1.2V, low-Vt devices with statistical models. All analysis, sizing and optimization have been performed using the WiCkeDTM tool at worst case operating conditions. Monte Carlo analysis has also been performed to verify the robustness of the circuit.