Design of Delta Sigma Modulators for Integrated Sensor Applications

The paper presents and explores the implementation of Delta Sigma Modulators for Integrated sensor applications. Elaborate design procedures and trade-offs faced have been presented. Starting at the block and topology level, comparisons of various feasible choices have been presented, along with the suited applications. Circuit level comparisons and trade-offs such as OTA and comparator design have also been presented. Finally, simulations have been shown for a modulator designed as per above criteria for integrated accelerometer applications. Keywords: MEMS, Delta Sigma Modulators, Dynamic Range, Integrated sensor

Interface Circuits for Microsensor Integrated Systems

ca. 200 words; this text will present the book in all promotional forms (e.g. flyers). Please describe the book in straightforward and consumer-friendly terms. [Recent advances in sensing technologies, especially those for Microsensor Integrated Systems, have led to several new commercial applications. Among these, low voltage and low power circuit architectures have gained growing attention, being suitable for portable long battery life devices. The aim is to improve the performances of actual interface circuits and systems, both in terms of voltage mode and current mode, in order to overcome the potential problems due to technology scaling and different technology integrations. Related problems, especially those concerning parasitics, lead to a severe interface design attention, especially concerning the analog front-end and novel and smart architecture must be explored and tested, both at simulation and prototype level. Moreover, the growing demand for autonomous systems gets even harder the interface design due to the need of energy-aware cost-effective circuit interfaces integrating, where possible, energy harvesting solutions. The objective of this Special Issue is to explore the potential solutions to overcome actual limitations in sensor interface circuits and systems, especially those for low voltage and low power Microsensor Integrated Systems. The present Special Issue aims to present and highlight the advances and the latest novel and emergent results on this topic, showing best practices, implementations and applications. The Guest Editors invite to submit original research contributions dealing with sensor interfacing related to this specific topic. Additionally, application oriented and review papers are encouraged.

Built-In test of MEMS capacitive accelerometers for field failures and aging degradation.

Postprint (published version

Automatic Bridge-based Interface for Differential Capacitive Full Sensing

Abstract The authors here propose, for the first time, an automatic analog interface for differential capacitance estimation, able to reveal and quantify both low and high (full-range) capacitive variations. The working principle is based on a modified De-Sauty AC bridge configuration where two differential capacitances and two resistances are employed, one of which is implemented by a Voltage Controlled Resistor (VCR). Through a suitable feedback loop, a very accurate estimation over the complete range of the differential capacitance variation is possible, while the bridge allows a continuous differential capacitance evaluation without the need of knowing the accurate value of the sensor baseline and/or its variation range. A general but very simple formula, considering both the "autobalancing" and the "out-of-equilibrium" ranges, is also given. Theoretical, experimental and simulated results are in a very good agreement. Sensitivity and resolution values, typical of sensors and their interfaces, have been determined in a practical case, showing satisfactory values

Advanced sensors technology survey

This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed

Development of a Capacitance Sensor System to Measure Ultra-Low Water Content in Crude Oil

The capacitance sensor system had been applied in various applications including measurement of water content in crude oil. The purity of crude oil is graded based on the water content found in it. The lesser the amount of water detected, the higher the purity of crude oil. The determination of water content is crucial as it directly reflects the quality of crude oil. However, the capacitance sensor system is limited to a high water concentration measurement. In this project, a higher resolution measurement is introduced which utilizes the capacitance sensor system based on phase angle conversion. The presence of water inside the crude oil is indicated by the change in capacitance value and results in a phase shift. The sensor system is capable of detecting a very small change of capacitance, meaning it is able to measure ultra-low water content inside the crude oil