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

AbstractThis 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

Main Parameters Characterization of Bulk CMOS Cross-Like Hall Structures

A detailed analysis of the cross-like Hall cells integrated in regular bulk CMOS technological process is performed. To this purpose their main parameters have been evaluated. A three-dimensional physical model was employed in order to evaluate the structures. On this occasion, numerical information on the input resistance, Hall voltage, conduction current, and electrical potential distribution has been obtained. Experimental results for the absolute sensitivity, offset, and offset temperature drift have also been provided. A quadratic behavior of the residual offset with the temperature was obtained and the temperature points leading to the minimum offset for the three Hall cells were identified

Offset Drift Dependence of Hall Cells with their Designed Geometry

In this paper, the performance of CMOS Hall Effect Sensors with four different geometries has been experimentally studied. Using a characteristic measurement system, the cells residual offset and its temperature behavior were determined. The offset, offset drift and sensitivity are quantities that were computed to determine the sensors performance. The temperature coefficient of specific parameters such as individual, residual offset and resistance has been also investigated. Therefore the optimum cell to fit the best in the performance specifications was identified. The variety of tested shapes ensures a good analysis on how the sensors performance changes with geometry

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.Peer Reviewe

Temperature considerations on Hall Effect sensors current-related sensitivity behaviour

The present paper focuses on evaluating the temperature effects on Hall Effect sensors sensitivity behavior. To this purpose, an analysis of the factors affecting the sensors current-related sensitivity is performed, consisting of several pertinent considerations. An analytical investigation of the carrier concentration temperature dependence including the freeze-out effect influence was performed. This information was subsequently included in accurate prediction of the current-related sensitivity temperature behavior. For a specific CMOS integration process of the Hall sensors, a parabolic curve is obtained for the relative variation of the current-related sensitivit

Temperature considerations on Hall Effect sensors current-related sensitivity behaviour

The present paper focuses on evaluating the temperature effects on Hall Effect sensors sensitivity behavior. To this purpose, an analysis of the factors affecting the sensors current-related sensitivity is performed, consisting of several pertinent considerations. An analytical investigation of the carrier concentration temperature dependence including the freeze-out effect influence was performed. This information was subsequently included in accurate prediction of the current-related sensitivity temperature behavior. For a specific CMOS integration process of the Hall sensors, a parabolic curve is obtained for the relative variation of the current-related sensitivity

Reducing cardiovascular burden in psoriasis patients by using specific therapies – How close are we?

Psoriasis is a chronic, systemic inflammatory disease that has gained popularity among scientific research from many promising perspectives on diagnosis and treatment. Individuals with psoriasis associate numerous comorbidities and have many predisposing factors in common especially with heart disease. Based on this, researchers tried to identify the common pathogenic mechanisms, the impact of risk factors on both pathologies, the influence of one disease on the another as well as the impact of novel therapies used in psoriasis on cardiovascular system, in order to improve the prognosis and quality of life of these patients. Areas of uncertainty. Pathogenic mechanisms involved both in psoriasis and atherosclerotic disease are not fully understood, especially in relationship with actual treatment strategies and their impact on prognosis. The purpose of this descriptive review is to summarize the latest available data, to see whether current treatment strategies of psoriatic disease should take into consideration the risk of cardiovascular disease (CVD) when one drug should be chosen at the expense of another. Data sources. Literature research was performed using electronic database (PubMed, Cochrane Library and Web of Science) between January 2010 and June 2022. We used different keywords and MeSH terms to generate the most relevant results regarding psoriasis and cardiovascular disease. First, we evaluated the titles and abstracts of the articles and we excluded papers that didn’t met selection criteria

Theoretical Model of Polymer Plasma Laser Ablation

Polymer plasma laser ablation has been investigated theoretically. An elegant mathematical tool using the fractal structure of space-time was developed. The model was verified with good accuracy on the existing experimental results

Hall Cells Offset Analysis and Modeling Approaches

The Hall Effect sensors are one of the most commonly used sensing technologies today. They are employed in many applications for direct magnetic field sensing and serve a multitude of low power applications within automotive and industrial electronics as current sensors, for contactless switching, position detection and in electronic compasses. In order to select Hall cells with high performance, good models that would accurately predict their characteristic parameters are undoubtedly necessary. Firstly, by setting up the actual research framework and giving details about the basic considerations regarding Hall Effect devices, the thesis domain is presented. A brief overview of the state-of-the-art in Hall Effect sensors development and applications on the market is included with emphasis on the offset levels achieved. The Hall voltage theoretical background and its rapid evaluation were provided. For six different types of Hall plates, three-dimensional representations were obtained for the inverse of the geometrical correction factor G. Various formulae for Hall mobility evaluation were provided, with a discussion on the relative error obtained in its calculation. Focusing on the analysis at device level, an attentive investigation of the geometrical correction factor as well as its maximization was proposed. In order to obtain maximum sensitivity for Hall cells integrated in the same process, a geometry that would provide a high geometrical correction factor it is advised to be chosen. The close connection between the general aspects and their associated details, regarding the twelve (designed and integrated) Hall cells, was presented. In premiere, three of them have been designed and proposed by the author. The reason behind the specific Hall cells geometries is announced and some designed layouts are given. To test the integrated cells, both an AC and DC automated measurements setup was used. This allows reliable and fast obtention of the desired experimental results. The Hall cells were tested for their input voltage-current characteristics at room temperature, resistance, resistance variation with the temperature, Hall voltage, dissipated power, etc. The absolute sensitivity versus the biasing current was also measured for all the integrated cells. The offset measurements results were just briefly presented, as there is another chapter entirely devoted to its detailed assessment. Parameters extraction was performed on specific tested Hall cells and the Hall cells linearity was also analyzed. A complex physical computing code, for predicting and assessing Hall cells performance with the aid of three dimensional simulations was developed and perfected. The influence of shape, dimensions, n-well concentration, contacts dimension and positioning with respect to the active region on the sensors performance were all aspects covered within this work. To this purpose, different constitutional devices including cross-like cells such as such as basic, L and XL and other shapes as the borderless and optimum have been modeled and subsequently tested for Hall voltage, absolute, current-related and voltage-related sensitivities. An analysis of the induced offset by a geometrical asymmetry has been performed on different cross-like Hall Effect sensors. In reverse reaction, any mix of various theoretical considerations can be validated now by three dimensional standard simulations. An optimum shape has been integrated which offers a good tradeoff between high sensitivity and low offset. The best device polarization scheme within each device has also been investigated. Selecting the best Hall sensor is closely related to the performance aimed to be achieved, may it be the highest sensitivity, the lowest offset or good power consumption. Further, without repeating ourselves, we can say that the proposed circuit model (implemented and repeatedly tested here) contains both geometrical and physical parameters and is able to predict the Hall voltage, sensitivity and their temperature drift. The temperature effects on Hall cells behavior has been carefully addressed and thoroughly analyzed, by implementation of Hall scattering factor and carrier concentration temperature dependence, including freeze-out effect for the latter. The full set of analytical equations governing this behavior has been implemented in VERILOG-A. Temperature dependence of Hall cells current-related sensitivity both by a full set of analytical equations and temperature coefficients has been investigated. In this way, the quadratic behavior of current-related sensitivity was proven. Moreover, the simulations performed for the integrated Hall cells and the results obtained are in a good agreement with the theory. In the actual conditions, after a specific calibration, the model developed by author will also be used for Hall Effect sensors offset prediction. As we already know, the offset and its drift are some of the most important figures of merit in the Hall cells performance assessment. The first objective of the present work was to develop Hall cells which will be able to provide magnetic equivalent offset at room temperature lower than ±30 μT and offset drifts with the temperature less that ±0.3 μT/ C. To measure the Hall cells offset, automated measurements setups were used to test the single, two and four phase residual offset, etc. Both AC and DC measurements were performed. Therefore, we have identified by intensive measurements the cell having the best performance in terms of offset at room temperature and offset temperature drift. An important section is devoted to the quadratic dependence of the residual offset with the biasing current. First and second order coefficient were extracted by curve fitting. To analyze and assess the offset voltage, the homogeneous models for Hall cells behavior investigation, previously presented, were transformed in non-homogeneous models. In this particular case, the non-homogeneous FEM model is built out of a homogeneous region in the middle (repetition of the elementary cell) plus different cells on the borders used to emulate the offset. These latter cells have their internal parameters changed. Various simulations were performed in circuit environment for offset analysis of particular Hall cells. The original non-homogeneous FEM model employing the first type of cell conducted by the author was used to predict misalignment offset for different asymmetries scenarios, as well as the offset temperature drift

Multi-analysis and modeling of asymmetry offset for Hall effect structures

The topological (asymmetry) offset voltage of CMOS cross-like Hall cells is analyzed in this paper. In order to attain the stated objective, different approaches have been considered. Both circuit and three-dimensional models have been developed. Variation of the misalignment offset with the biasing current has been studied through physical and circuit models. The latter is a non-homogenous finite elements model, which relies on using parameterized resistances and current-controlled current sources, of CMOS Hall cells. The displacement offset for various asymmetries and the offset variation with the temperature were investigated through the circuit model developed. Various experimental results for the single and magnetic equivalent offset have also been provided