Search results for "CIRCUIT"
showing 10 items of 936 documents
Theoretical design of magnetic wires from acene and nanocorone derivatives
2016
Theoretical calculations on a series of molecular models based on amino derivatives of linear and cycled acenes acting as organic linkers between two copper(ii) ions have shown a wire-like magnetic behaviour, so that the intermetallic magnetic communication does not vanish when the linker becomes larger due to its polyradical nature. Hence, these models can be considered as molecular magnetic wires, which can be used as active components for molecular spintronics, where the information transport is based on spin carriers instead of the more conventional charge transport. The nature of the spin ground state along these two series of models is governed by the topology of the organic linker, i…
Digital background calibration algorithm and its FPGA implementation for timing mismatch correction of time-interleaved ADC
2019
Sample time error can degrade the performance of time-interleaved analog to digital converters (TIADCs). A fully digital background algorithm is presented in this paper to estimate and correct the timing mismatch errors between four interleaved channels, together with its hardware implementation. The proposed algorithm provides low computation burden and high performance. It is based on the simplified representation of the coefficients of the Lagrange interpolator. Simulation results show that it can suppress error tones in all of the Nyquist band. Results show that, for a four-channel TIADC with 10-bit resolution, the proposed algorithm improves the signal to noise and distortion ratio (SN…
Magnetic domain-wall racetrack memory for high density and fast data storage
2012
The racetrack memory device is a new concept of Magnetic RAM (MRAM) based on controlling domain wall (DW) motion in ferromagnetic nanowires. It promises ultra-high storage density thanks to the possibility to store multiple narrow DWS per memory cell. By using read and write heads based on magnetic tunnel junctions (MTJ) with perpendicular magnetic anisotropy (PMA) fast data access speed can also be achieved. Thereby the racetrack memory can be used as universal storage to address both embedded and standalone applications. In this paper, we present the device physics, integration circuit and architecture designs of a racetrack memory based on MTJs with PMA. Mixed SPICE simulations at 65 nm …
Design of an image processing integrated circuit for real time edge detection
2003
Presents the design of a real time image processing micro-system to detect defects on manufacturing products. The analysis method is based on an edge detection algorithm (differential operators) to select the information related to the structure of the objects present in the image. The edge calculation function has been integrated in a standard cell circuit using a CMOS 1.5 mu m process. The ASIC has been implemented and tested in an image processing microsystem with a CCD camera. Results show an improvement of performances (speed, noise, size reduction system characterization, etc. . .) in comparison with the first prototypes (software implementation and printed board with standard compone…
Analysis of Transition Metal Oxides based Heterojunction Solar Cells with S-shaped J-V curves
2020
The use of transition metal oxides for the selective carrier contact in the crystalline silicon solar cells technology is rising to interest for the excellent optoelectrical properties of these materials whose implementation, however, can result in lousy performing cells due to an S-shaped electrical characteristic. In this paper, we fabricated solar cells showing S-shaped J-V curve and carried out an analysis of the reasons of such behavior using a model involving the series of a standard cell equivalent circuit with a Schottky junction in order to explain these atypical performances. A good matching between the experimental measurements and the adopted theoretical model was obtained. The …
Importance of the Window Function Choice for the Predictive Modelling of Memristors
2021
Window functions are widely employed in memristor models to restrict the changes of the internal state variables to specified intervals. Here, we show that the actual choice of window function is of significant importance for the predictive modelling of memristors. Using a recently formulated theory of memristor attractors, we demonstrate that whether stable fixed points exist depends on the type of window function used in the model. Our main findings are formulated in terms of two memristor attractor theorems, which apply to broad classes of memristor models. As an example of our findings, we predict the existence of stable fixed points in Biolek window function memristors and their absenc…
Time delay induced effects on control of linear systems under random excitation
2001
Recursive formulas in terms of statistics of the response of linear systems with time delay under normal white noise input are developed. Two alternative methods are presented, in order to capture the time delay effects. The first is given in an approximate solution obtained by expanding the control force in a Taylor series. The second, available for the stationary solution (if it exists) gets the variance of the controlled system, with time delay in an analytical form. The efficacy loss in terms of statistics of the response is discussed in detail.
An Efficient Implementation of Distributed Routing Algorithms for NoCs
2008
The design of NoCs for multi-core chips introduces new design constraints like power consumption, area, and ultra low latencies. Although 2D meshes are preferred, heterogeneous blocks, fabrication faults, reliability issues, and chip virtualization may lead to the need of irregular topologies or regions. In this situation, efficient routing becomes a challenge. Although the use of routing tables at switches is flexible, it does not scale in terms of latency and area due to its memory requirements. LBDR (logic-based distributed routing) is proposed as a new routing method that removes the need of using routing tables at all. LBDR enables the implementation of many routing algorithms on most …
Signatures of noise-enhanced stability in metastable state
2005
The lifetime of a metastable state in the transient dynamics of an overdamped Brownian particle is analyzed, both in terms of the mean first passage time and by means of the mean growth rate coefficient. Both quantities feature non monotonic behaviors as a function of the noise intensity, and are independent signatures of the noise enhanced stability effect. They can therefore be alternatively used to evaluate and estimate the presence of this phenomenon, which characterizes metastability in nonlinear physical systems.
Atypical transistor-based chaotic oscillators: Design, realization, and diversity
2017
In this paper, we show that novel autonomous chaotic oscillators based on one or two bipolar junction transistors and a limited number of passive components can be obtained via random search with suitable heuristics. Chaos is a pervasive occurrence in these circuits, particularly after manual adjustment of a variable resistor placed in series with the supply voltage source. Following this approach, 49 unique circuits generating chaotic signals when physically realized were designed, representing the largest collection of circuits of this kind to date. These circuits are atypical as they do not trivially map onto known topologies or variations thereof. They feature diverse spectra and predom…