Types Of Current Conveyors Research Articles

A New Type of Current Conveyor and its Application in Fully Balanced Differential Current-Mode Elliptic Filter Design

A New Type of Current Conveyor and its Application in Fully Balanced Differential Current-Mode Elliptic Filter Design This paper introduces a new type of CMOS-based current conveyor: current controlled fully balanced second generation current conveyor (CFBCCII) element which has a pair of differential Y terminals, a pair of differential X terminals and two pairs of Z terminals. The proposed circuit offers electronic tuning possibilities by means of a current adjustable intrinsic resistance at its X terminal. An elliptic filter realization is described as an example for its application in a current-mode fully balanced filter design, where the intrinsic resistors in CFBCCIIs are used for the electronic tuning of the characteristic filter frequency.

Synthesis of Oscillators Using Limit Variables and NAM Expansion

A systematic synthesis procedure for generating second-order grounded passive element canonic oscillators is given. The synthesis procedure is based on using nodal admittance matrix (NAM) expansion with the bracket method as well as using the infinity parameters. The resulting derived oscillators include circuits using various types of current conveyors. Two classes of oscillators are considered in this paper, and they have the advantages of having independent control on the condition of oscillation and on the frequency of oscillation by varying two different grounded resistors. The two classes of oscillators considered can be easily compensated for the parasitic element effects introduced by the current conveyors. This paper is considered to be continuation to the recently published paper on oscillators using NAM expansion D. G. Haigh et al. (2006). This is the first paper in the literature which uses limit-variables called infinity-variables D. G. Haigh et al. (2005) in the synthesis of oscillator circuits. Simulation results demonstrating the practicality of some of the generated circuits are included.

Design of high-linear CMOS circuit using a constant transconductance method for gamma-ray spectroscopy system

We propose a novel circuit to be applied to the front-end integrated circuits of gamma-ray spectroscopy systems. Our circuit is designed as a type of current conveyor (ICON) employing a constant- g m (transconductance) method which can significantly improve the linearity in the amplified signals by using a large time constant and the time-invariant characteristics of an amplifier. The constant- g m method is obtained by a feedback control which keeps the transconductance of the input transistor constant. To verify the performance of the propose circuit, the time constant variations for the channel resistances are simulated with the TSMC 0.18 μ m transistor parameters using HSPICE, and then compared with those of a conventional ICON. As a result, the proposed ICON shows only 0.02% output linearity variation and 0.19% time constant variation for the input amplitude up to 100 mV. These are significantly small values compared to a conventional ICON's 1.39% and 19.43%, respectively, for the same conditions.

Generation of current conveyor based oscillators using nodal admittance matrix expansion

A new approach in the systematic synthesis of current conveyor based active RC canonic oscillators is given. The synthesis procedure is based on the generalized systematic synthesis framework using admittance matrix expansion. The resulting derived oscillators include many novel oscillators, using various types of current conveyors and inverting current conveyors. The oscillators considered in this paper uses the minimum number of passive elements namely two capacitors and three resistors necessary to have independent control on the condition of oscillation and on the frequency of oscillation. The generated oscillators employ two grounded capacitors and have the advantage of their ability to absorb parasitic element effects. Three classes are considered in this paper, class I oscillators have a common node between one of the capacitors and one of the two grounded resistors. Class II oscillators have a common node between one of the capacitors and the floating resistor. Class III has all three resistors being grounded and one of them shares a node with one of the capacitors. It should be noted that this is the first paper in the literature to use nodal admittance matrix expansion in the generation of current conveyor oscillators. Spice simulation results are included to support the theory. The proposed method can be generalized to other active devices.

A CMOS Operational Floating Conveyor

A CMOS realization for operational floating current conveyor (OFC), which can be reconfigured as various types of current conveyors, has been described. The proposed OFC has very low power consumption and a bandwidth of 100 MHz. For ±2.5 V power supply, the voltage transfer takes place from-1V to 2V. P-Spice simulation confirms the high performance of the proposed circuit structures.

Current-controlled CMOS transconductor using bisection of input voltage

The CMOS transconductor presented is based on bisection of the input voltage and use of a new type of current conveyor. The circuit operates at a supply of ±1.5 V. Simulation results show linearity error lower than 0.8% for input voltage swings up to ±0.5 V, and 5% frequency bandwidth of 97 MHz.

Translinear current conveyors implementation

Integrable translinear implementations of all four types of current conveyors (CC) are reported. Using a single model-1 current-controlled current source (model-1 CCCS), with unity gain, the CC I+ and CC II+ current conveyors are designed. When, in addition, a second CCCS is used (to reverse the current at port z), the CC I− and CC II− are obtained.