An expedition under "Projet Rhéomarge" traced marine deposits along the Sénégal estuary. Leveled and dated samples have made it possible to reconstruct portions of paleogeoids 6500, 5500, 1800 years before present. The surfaces these geoids show that tilt across continental margins predicted by mathematical models is less than 1 meter from coast 120 kilometers inland.

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The potential application range of spintronic devices is wide. However, few works were carried out in the field compact modeling such devices. lack models dramatically increases design complexity circuits using In this paper, focus made on magnetic tunnel junctions (MTJs). It presented a set two papers: first part deals with aspects MTJ, whereas second one covers electrical aspects. part, dynamic...

A new compact model of a magnetic tunnel junction (MTJ) is presented in this paper. This intended to describe the behavior MTJ and take as well non-linear electronic transport phenomena into account. It should be suitable for circuits simulation thus, it must simple (no finite element approach, analytical current versus voltage characteristic only). For purpose, some assumptions are made. The separated two entities. first one concerns magnetization ferromagnetic thin film. other focuses on...

This paper presents a 3 dimensional magnetometer based on Hall effect sensors integrated without any post processing in standard low cost 0.35 mum CMOS technology. The system is dedicated to magnetic pulses measurements under strong static field. Two vertical devices (VHD) are sensitive the components of field oriented plane chip, while horizontal device (HHD) component orthogonally chip. identical instrumental chains perform amplification voltages. implements compensation and allows measure...

Operating temperature and gradients are of critical concern in the design planar integrated circuits (ICs) bound to be exacerbated upcoming 3D technologies. However, a thermal aware ICs allows issues kept minimum. Previously, simulator Cadence® environment that electro-thermal simulations carried out at transistor level has been presented. Since this is based on use Verilog-A® hardware description language, electrothermal simulation can performed as long high-level models provided. In paper,...

This article demonstrates a new type of magnetic sensor using perpendicular spin transfer torque tunnel junction (MTJ). The sensing element has cylindrical shape 50 nm in diameter and is to our knowledge among the smallest ever reported. describes principle operation associated signal processing electronics, which delivers proportional external field. Experimental results are detailed compared state-of-the-art commercially available integrated sensors as well published magnetoresistive based...

Many sensitive devices are based on Wheatstone bridge structures or can be modeled as bridges like Hall effect magnetic sensors. These sensors require a biasing circuit, and many solutions were proposed. However, up to now, none of them gives the opportunity cascade several sensors, while such help in improving signal-to-noise-ratio (SNR) removing some parasitic effects through direct summing/subtraction sensing/parasitic effects. The circuit this paper presents is an operational...

The Vertical Hall Device integrable in a shallow N-well, and thus compatible with Low-Voltage CMOS processes, i.e. the LV-VHD, was proposed five years ago. Its layout is similar to of HV-VHD, conventional 5-contact VHD integrated deep N-well High-Voltage processes. However, voltage picked-up from external contacts while it internal HV-VHD. Such sensing schemes make not obvious application well-known Spinning-Current Technique (SCT) used Horizontal (HHD) for offset 1/f noise attenuation. In...

In this paper, we present an integrated ac current sensor based on sensitivity-optimized horizontal Hall effect devices and a differential readout chain. This microsystem has been designed for 5-A rms nominal measurement with 5-kV galvanic isolation 0.5% accuracy after calibration from 250 mA to 5 A, over 1.5-kHz bandwidth, which allows up 30th (25th) harmonic detection in 50-Hz (60-Hz) applications. qualifies the class 1 products according international norms energy meters (IEC44-1...

The topic of this paper is the development biological models for 3D reaction-diffusion phenomena that can be used in any circuit electronic design automation environment simulation biosensors. Biological systems involve such are described by partial differential equations. Our approach consists discretizing these equations according to finite-difference method and converting resulting ordinary into an assembly elementary equivalent circuits directly simulated with SPICE. main interest...

Based on a qualitative study of the Stoner-Wohlfarth model, we point out that driving magnetic tunnel junction (MTJ) with an alternative two-dimensional field allows to measure simultaneously two components external field. Only one single MTJ without pinning layer is needed both parallel plane. The response magnetometer does not depend resistance or amplitude its variations. A prototype has been manufactured and encouraging experimental results are presented. Sensitivities higher than 500...

Currently, the lack of compact magnetic tunnel junction (MTJ) model is a truly limiting factor for design spintronics circuits. In this paper, we present MTJ written in VHDL-AMS. This behavioral based on Stoner-Wohlfarth and takes most important phenomena such as coupling, capacitance, magnetization dependent conductance into account. The method employed to two layer detailed. Applications simulation operation magnetometer also presented.

Hall-sensors integrated in CMOS technology are good candidates for the design of low-cost magnetometers. However, one their major limitations is 0-field offset, and it essential to take this effect into account very early steps process. For purpose, we recently developed a new compact model horizontal cross-shaped Hall-effect device. It based on physical considerations takes all device offset sources account. applications where issue critical, well known spinning-current technique (SC) can...

The unique relationship between the coordinates in bore of a Magnetic Resonance Imaging (MRI) scanner and magnetic field gradients used for MRI allows building localization system based on measurement these gradients. We have previously presented miniature 3D Hall probe integrated low cost, voltage 0.35μm CMOS chip from which we were able to measure gradient maps 1.5T 3T scanners. In this paper, has been tracking device prototype an algorithm was built determine position probe. First...

Vertical Hall-effect devices (VHDs) are CMOS integrated sensors dedicated to the measurement of magnetic field in plane chip. At low frequency performances severely reduced by 1/f noise. We recently proposed a theoretical study which confirm capability spinning current technique lower noise on Low-Voltage VHD. In this paper, we practical way for implementation technique. Experimental results bring out significant improvements. An offset 0.1 mT and resolution 37 μT has been measured over 1.6...

In this paper, we discuss the conception and performances of a monolithic microsystem for magnetic field measurement built in standard 0.6 /spl mu/m CMOS technology. It is shown that 5.2 microtesla resolution over 1 kHz bandwidth (5 to kHz) can be achieved by combining smart Hall effect based sensing device appropriate analog conditioning electronics. The study focuses on methods used drive up sensor sensitivity down system noise level order achieve stated resolution. New circuitry proposed biasing.