Maria-Alexandra Paun

Comparative Study on the Performance of Five Different Hall Effect Devices

Five different Hall Effect sensors were modeled and their performance evaluated using a three dimensional simulator. The physical structure of the implemented sensors reproduces a certain technological fabrication process. Hall voltage, absolute, current-related, voltage-related and power-related sensitivities were obtained for each sensor. The effect of artificial offset was also investigated for cross-like structures. The simulation procedure guides the designer in choosing the Hall cell optimum shape, dimensions and device polarization conditions that would allow the highest performance.

Hall Effect Sensors Design, Integration and Behavior Analysis

The present paper focuses on various aspects regarding Hall Effect sensors’ design, integration, and behavior analysis. In order to assess their performance, different Hall Effect geometries were tested for Hall voltage, sensitivity, offset, and temperature drift. The residual offset was measured both with an automated measurement setup and by manual switching of the individual phases. To predict Hall sensors performance prior to integration, three-dimensional physical simulations were performed.

A Circuit Model for CMOS Hall Cells Performance Evaluation including Temperature Effects

In order to provide the information on their Hall voltage, sensitivity, and drift with temperature, a new simpler lumped circuit model for the evaluation of various Hall cells has been developed. In this sense, the finite element model proposed by the authors in this paper contains both geometrical parameters (dimensions of the cells) and physical parameters such as the mobility, conductivity, Hall factor, carrier concentration, and the temperature influence on them. Therefore, a scalable finite element model in Cadence, for behavior simulation in circuit environment of CMOS Hall effect devices, with different shapes and technologies assessing their performance, has been elaborated.

Evaluation of characteristic parameters for high performance hall cells

The current work focuses on presenting specific Hall cells with high performance, and their corresponding parameters. The design, integration, measurements and model development for their performance assessment are necessary stages considered in the generation of the Hall cells. Experimental results regarding the Hall cells absolute sensitivity, offset and offset temperature drift are provided for two particular structures exhibiting the best behavior in terms of maximum sensitivity and lowest offset. Three-dimensional physical simulations were performed for the structures and the Hall mobility was extracted. Representation of the inverse of the geometrical correction factor for the Greek-cross Hall cell is also provided

Temperature influence investigation on Hall Effect sensors performance using a lumped circuit model

In order to provide the information on their Hall voltage, sensitivity and drift with temperature, a new simpler lumped circuit model for the evaluation of various Hall Effect sensors has been developed. In this sense, the finite element model associated contains both geometrical parameters (dimensions of the cells) and physical parameters such as mobility, conductivity, Hall factor, carrier concentration and the temperature influence on them. Therefore, a scalable finite element model in Cadence, for integrating in circuit environment CMOS Hall Effect devices with different shapes and technologies and assessing their performance, has been also elaborated.

Regular Bulk CMOS Hall Effect Sensors Employment in Solid-State Power and Energy Meters.

Abstract This paper is intended to present an advanced technique to be used in solid-state power and energy meters, more specifically through the employment of the Hall effect sensors. From a qualitative point of view, an investigation into the sensing device is performed and geometrical consideration of the Hall cells onto the performance is analyzed. Different Hall cells (basic, L, XL, borderless and optimum) have been fabricated in a regular bulk CMOS technology and their main parameters were extracted. To this purpose, experimental results for the offset and sensitivity of different Hall cells are obtained. The dissipated power as well as the power-related sensitivity is calculated, for the five Hall cells in discussion.

Effect of structure scaling on the offset levels for CMOS Hall Effect sensors

The effect of the structure scaling on the Hall Effect sensors performance (including offset values) is investigated. To this purpose, the Hall devices have been integrated in a regular bulk CMOS technology and tested for their main parameters. The comparative analysis is focused on three Hall cells (basic, L, XL), with progressive scaled up dimensions. Measurements results for the sensitivity, offset voltage and magnetic equivalent offset are included for the three considered Hall cells.

Three-dimensional modeling and analysis of antennas in cochlear implants

This work is devoted to the modeling and analysis of the antennas in the cochlear implants. In order to accurately characterize the antenna, a three-dimensional model has been built, where precise dimensions of the loop antenna are given. The most important performance indicators have been numerically assessed. The total electric field three-dimensional polar representation is included. The radiation pattern. Smith charts and Smith contour plots are also obtained.

Hall mobility study of hall structures in two different CMOS technological processes

This paper studies the Hall mobility of Hall structures integrated in two CMOS technological processes, regular bulk and Silicon on Insulator respectively. The main character of this study is the Basic Hall cell, for which accurate dimensions (length and width of the active region, electrical contacts size and area of the p-substrate) are given. To this purpose, three-dimensional physical models are considered for the Basic Hall structure in both processes, and the Hall mobility is evaluated. All the necessary doping profiles are provided. Regarding the absolute sensitivity of the Hall cells, both experimental and simulated data is provided for the bulk Basic cell, while simulation results are included for the SOI Basic Hall cell. A theoretical computation approach and specific equations are presented for the Hall mobility evaluation. A discussion of the Hall mobility is made in both technological processes, by providing numerical evaluation through physical simulations to the behavior of this important parameter. For both regular bulk and SOI Basic Hall cell, the maximum values as well as the plateau region are identified for the Hall mobility.

Multilayered tissues model for wave propagation loss assessment in cochlear implants

In this paper, a study of the power loss attenuation of the plane wave travelling through the tissue layers, from the outside to the inside of the skull within a cochlear implant, is performed. Different implantation depths of the internal antenna from 10 to 30 mm are considered. To this purpose, the gain and attenuation in dB are studied. A multilayer tissue model is developed, consisting of mainly skin, mastoid bone and brain. An s-parameter analysis is also carried out, using loop antennas and simulated head tissue. Ansoft Ansys® HFSS software is used for electro-magnetic simulations of the antennas, placed in different types of human tissues. Smith charts for antenna placed in both skin and multi-tissue model are included.