Development of MEMS Capacitive Sensor Using a MOSFET Structure
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Wireless Accelerometer - G-Force Max & Avg
The Leader in Low-Cost, Remote Monitoring Solutions Wireless Accelerometer - G-Force Max & Avg General Description Monnit Sensor Core Specifications The RF Wireless Accelerometer is a digital, low power, • Wireless Range: 250 - 300 ft. (non line-of-sight / low profile, capacitive sensor that is able to measure indoors through walls, ceilings & floors) * acceleration on three axes. Four different • Communication: RF 900, 920, 868 and 433 MHz accelerometer types are available from Monnit. • Power: Replaceable batteries (optimized for long battery life - Line-power (AA version) and solar Free iMonnit basic online wireless (Industrial version) options available sensor monitoring and notification • Battery Life (at 1 hour heartbeat setting): ** system to configure sensors, view data AA battery > 4-8 years and set alerts via SMS text and email. Coin Cell > 2-3 years. Industrial > 4-8 years Principle of Operation * Actual range may vary depending on environment. ** Battery life is determined by sensor reporting Accelerometer samples at 800 Hz over a 10 second frequency and other variables. period, and reports the measured MAXIMUM value for each axis in g-force and the AVERAGE measured g-force on each axis over the same period, for all three axes. (Only available in the AA version.) This sensor reports in every 10 seconds with this data. Other sampling periods can be configured, down to one second and up to 10 minutes*. The data reported is useful for tracking periodic motion. Sensor data is displayed as max and average. Example: • Max X: 0.125 Max Y: 1.012 Max Z: 0.015 • Avg X: 0.110 Avg Y: 1.005 Avg Z: 0.007 * Customer cannot configure sampling period on their own. -
Measurement of the Earth Tides with a MEMS Gravimeter
1 Measurement of the Earth tides with a MEMS gravimeter ∗ y ∗ y ∗ ∗ ∗ 2 R. P. Middlemiss, A. Samarelli, D. J. Paul, J. Hough, S. Rowan and G. D. Hammond 3 The ability to measure tiny variations in the local gravitational acceleration allows { amongst 4 other applications { the detection of hidden hydrocarbon reserves, magma build-up before volcanic 5 eruptions, and subterranean tunnels. Several technologies are available that achieve the sensi- p 1 6 tivities required for such applications (tens of µGal= Hz): free-fall gravimeters , spring-based 2; 3 4 5 7 gravimeters , superconducting gravimeters , and atom interferometers . All of these devices can 6 8 observe the Earth Tides ; the elastic deformation of the Earth's crust as a result of tidal forces. 9 This is a universally predictable gravitational signal that requires both high sensitivity and high 10 stability over timescales of several days to measure. All present gravimeters, however, have limita- 11 tions of excessive cost (> $100 k) and high mass (>8 kg). We have built a microelectromechanical p 12 system (MEMS) gravimeter with a sensitivity of 40 µGal= Hz in a package size of only a few 13 cubic centimetres. We demonstrate the remarkable stability and sensitivity of our device with a 14 measurement of the Earth tides. Such a measurement has never been undertaken with a MEMS 15 device, and proves the long term stability of our instrument compared to any other MEMS device, 16 making it the first MEMS accelerometer to transition from seismometer to gravimeter. This heralds 17 a transformative step in MEMS accelerometer technology. -
A GUIDE to USING FETS for SENSOR APPLICATIONS by Ron Quan
Three Decades of Quality Through Innovation A GUIDE TO USING FETS FOR SENSOR APPLICATIONS By Ron Quan Linear Integrated Systems • 4042 Clipper Court • Fremont, CA 94538 • Tel: 510 490-9160 • Fax: 510 353-0261 • Email: [email protected] A GUIDE TO USING FETS FOR SENSOR APPLICATIONS many discrete FETs have input capacitances of less than 5 pF. Also, there are few low noise FET input op amps Linear Systems that have equivalent input noise voltages density of less provides a variety of FETs (Field Effect Transistors) than 4 nV/ 퐻푧. However, there are a number of suitable for use in low noise amplifier applications for discrete FETs rated at ≤ 2 nV/ 퐻푧 in terms of equivalent photo diodes, accelerometers, transducers, and other Input noise voltage density. types of sensors. For those op amps that are rated as low noise, normally In particular, low noise JFETs exhibit low input gate the input stages use bipolar transistors that generate currents that are desirable when working with high much greater noise currents at the input terminals than impedance devices at the input or with high value FETs. These noise currents flowing into high impedances feedback resistors (e.g., ≥1MΩ). Operational amplifiers form added (random) noise voltages that are often (op amps) with bipolar transistor input stages have much greater than the equivalent input noise. much higher input noise currents than FETs. One advantage of using discrete FETs is that an op amp In general, many op amps have a combination of higher that is not rated as low noise in terms of input current noise and input capacitance when compared to some can be converted into an amplifier with low input discrete FETs. -
Discrete Cosine Transform Based Image Fusion Techniques VPS Naidu MSDF Lab, FMCD, National Aerospace Laboratories, Bangalore, INDIA E.Mail: [email protected]
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NAL-IR Journal of Communication, Navigation and Signal Processing (January 2012) Vol. 1, No. 1, pp. 35-45 Discrete Cosine Transform based Image Fusion Techniques VPS Naidu MSDF Lab, FMCD, National Aerospace Laboratories, Bangalore, INDIA E.mail: [email protected] Abstract: Six different types of image fusion algorithms based on 1 discrete cosine transform (DCT) were developed and their , k 1 0 performance was evaluated. Fusion performance is not good while N Where (k ) 1 and using the algorithms with block size less than 8x8 and also the block 1 2 size equivalent to the image size itself. DCTe and DCTmx based , 1 k 1 N 1 1 image fusion algorithms performed well. These algorithms are very N 1 simple and might be suitable for real time applications. 1 , k 0 Keywords: DCT, Contrast measure, Image fusion 2 N 2 (k 1 ) I. INTRODUCTION 2 , 1 k 2 N 2 1 Off late, different image fusion algorithms have been developed N 2 to merge the multiple images into a single image that contain all useful information. Pixel averaging of the source images k 1 & k 2 discrete frequency variables (n1 , n 2 ) pixel index (the images to be fused) is the simplest image fusion technique and it often produces undesirable side effects in the fused image Similarly, the 2D inverse discrete cosine transform is defined including reduced contrast. To overcome this side effects many as: researchers have developed multi resolution [1-3], multi scale [4,5] and statistical signal processing [6,7] based image fusion x(n1 , n 2 ) (k 1 ) (k 2 ) N 1 N 1 techniques. -
Utilising Accelerometer and Gyroscope in Smartphone to Detect Incidents on a Test Track for Cars
Utilising accelerometer and gyroscope in smartphone to detect incidents on a test track for cars Carl-Johan Holst Data- och systemvetenskap, kandidat 2017 Luleå tekniska universitet Institutionen för system- och rymdteknik LULEÅ UNIVERSITY OF TECHNOLOGY BACHELOR THESIS Utilising accelerometer and gyroscope in smartphone to detect incidents on a test track for cars Author: Examiner: Carl-Johan HOLST Patrik HOLMLUND [email protected] [email protected] Supervisor: Jörgen STENBERG-ÖFJÄLL [email protected] Computer and space technology Campus Skellefteå June 4, 2017 ii Abstract Utilising accelerometer and gyroscope in smartphone to detect incidents on a test track for cars Every smartphone today includes an accelerometer. An accelerometer works by de- tecting acceleration affecting the device, meaning it can be used to identify incidents such as collisions at a relatively high speed where large spikes of acceleration often occur. A gyroscope on the other hand is not as common as the accelerometer but it does exists in most newer phones. Gyroscopes can detect rotations around an arbitrary axis and as such can be used to detect critical rotations. This thesis work will present an algorithm for utilising the accelerometer and gy- roscope in a smartphone to detect incidents occurring on a test track for cars. Sammanfattning Utilising accelerometer and gyroscope in smartphone to detect incidents on a test track for cars Alla smarta telefoner innehåller idag en accelerometer. En accelerometer analyserar acceleration som påverkar enheten, vilket innebär att den kan användas för att de- tektera incidenter så som kollisioner vid relativt höga hastigheter där stora spikar av acceleration vanligtvis påträffas. -
Temperature Compensation Circuit for ISFET Sensor
Journal of Low Power Electronics and Applications Article Temperature Compensation Circuit for ISFET Sensor Ahmed Gaddour 1,2,* , Wael Dghais 2,3, Belgacem Hamdi 2,3 and Mounir Ben Ali 3,4 1 National Engineering School of Monastir (ENIM), University of Monastir, Monastir 5000, Tunisia 2 Electronics and Microelectronics Laboratory, LR99ES30, Faculty of Sciences of Monastir, University of Monastir, Monastir 5000, Tunisia; [email protected] (W.D.); [email protected] (B.H.) 3 Higher Institute of Applied Sciences and Technology of Sousse (ISSATSo), University of Sousse, Sousse 4003, Tunisia; [email protected] 4 Nanomaterials, Microsystems for Health, Environment and Energy Laboratory, LR16CRMN01, Centre for Research on Microelectronics and Nanotechnology, Sousse 4034, Tunisia * Correspondence: [email protected]; Tel.: +216-50998008 Received: 3 November 2019; Accepted: 21 December 2019; Published: 4 January 2020 Abstract: PH measurements are widely used in agriculture, biomedical engineering, the food industry, environmental studies, etc. Several healthcare and biomedical research studies have reported that all aqueous samples have their pH tested at some point in their lifecycle for evaluation of the diagnosis of diseases or susceptibility, wound healing, cellular internalization, etc. The ion-sensitive field effect transistor (ISFET) is capable of pH measurements. Such use of the ISFET has become popular, as it allows sensing, preprocessing, and computational circuitry to be encapsulated on a single chip, enabling miniaturization and portability. However, the extracted data from the sensor have been affected by the variation of the temperature. This paper presents a new integrated circuit that can enhance the immunity of ion-sensitive field effect transistors (ISFET) against the temperature. -
Basic Principles of Inertial Navigation
Basic Principles of Inertial Navigation Seminar on inertial navigation systems Tampere University of Technology 1 The five basic forms of navigation • Pilotage, which essentially relies on recognizing landmarks to know where you are. It is older than human kind. • Dead reckoning, which relies on knowing where you started from plus some form of heading information and some estimate of speed. • Celestial navigation, using time and the angles between local vertical and known celestial objects (e.g., sun, moon, or stars). • Radio navigation, which relies on radio‐frequency sources with known locations (including GNSS satellites, LORAN‐C, Omega, Tacan, US Army Position Location and Reporting System…) • Inertial navigation, which relies on knowing your initial position, velocity, and attitude and thereafter measuring your attitude rates and accelerations. The operation of inertial navigation systems (INS) depends upon Newton’s laws of classical mechanics. It is the only form of navigation that does not rely on external references. • These forms of navigation can be used in combination as well. The subject of our seminar is the fifth form of navigation – inertial navigation. 2 A few definitions • Inertia is the property of bodies to maintain constant translational and rotational velocity, unless disturbed by forces or torques, respectively (Newton’s first law of motion). • An inertial reference frame is a coordinate frame in which Newton’s laws of motion are valid. Inertial reference frames are neither rotating nor accelerating. • Inertial sensors measure rotation rate and acceleration, both of which are vector‐ valued variables. • Gyroscopes are sensors for measuring rotation: rate gyroscopes measure rotation rate, and integrating gyroscopes (also called whole‐angle gyroscopes) measure rotation angle. -
Full Auto-Calibration of a Smartphone on Board a Vehicle Using IMU and GPS Embedded Sensors
Full auto-calibration of a smartphone on board a vehicle using IMU and GPS embedded sensors Javier Almaz´an, Luis M. Bergasa, J. Javier Yebes, Rafael Barea and Roberto Arroyo Abstract| Nowadays, smartphones are widely used Smartphones provide two kinds of measurements. The in the world, and generally, they are equipped with first ones are relative to the world, such as GPS and many sensors. In this paper we study how powerful magnetometers. The second ones are relative to the the low-cost embedded IMU and GPS could become for Intelligent Vehicles. The information given by device, such as accelerometers and gyroscopes. Knowing accelerometer and gyroscope is useful if the relations the relation between the smartphone reference system between the smartphone reference system, the vehicle and the world reference system is very important in order reference system and the world reference system are to reference the second kind of measurements globally [3]. known. Commonly, the magnetometer sensor is used In other words, working with this kind of measurements to determine the orientation of the smartphone, but its main drawback is the high influence of electro- involves knowing the pose of the smartphone in the magnetic interference. In view of this, we propose a world. novel automatic method to calibrate a smartphone Intelligent Vehicles can be helped by using in-vehicle on board a vehicle using its embedded IMU and smartphones to measure some driving indicators. On the GPS, based on longitudinal vehicle acceleration. To one hand, using smartphones requires no extra hardware the best of our knowledge, this is the first attempt to estimate the yaw angle of a smartphone relative to a mounted in the vehicle, offering cheap and standard vehicle in every case, even on non-zero slope roads. -
A Novel MEMS Pressure Sensor with MOSFET on Chip
A Novel MEMS Pressure Sensor with MOSFET on Chip Zhao-Hua Zhang *, Yan-Hong Zhang, Li-Tian Liu, Tian-Ling Ren Tsinghua National Laboratory for Information Science and Technology Institute of Microelectronics, Tsinghua University Beijing 100084, China [email protected] Abstract—A novel MOSFET pressure sensor was proposed Figure 1. Two PMOSFET’s and two piezoresistors are based on the MOSFET stress sensitive phenomenon, in which connected to form a Wheatstone bridge. To obtain the the source-drain current changes with the stress in channel maximum sensitivity, these components are placed near the region. Two MOSFET’s and two piezoresistors were employed four sides of the silicon diaphragm, which are the high stress to form a Wheatstone bridge served as sensitive unit in the regions. The MOSFET’s has the same structure parameter novel sensor. Compared with the traditional piezoresistive W/L, same threshold voltage VT and gate-source voltage VGS pressure sensor, this MOSFET sensor’s sensitivity is improved (equal to VG-Vdd). They are designed to work in the significantly, meanwhile the power consumption can be saturation region. The piezoresistors also have the same decreased. The fabrication of the novel pressure sensor is low- resistance R . cost and compatible with standard IC process. It shows the 0 great promising application of MOSFET-bridge-circuit structure for the high performance pressure sensor. This kind of MEMS pressure sensor with signal process circuit on the same chip can be used in positive or negative Tire Pressure Monitoring System (TPMS) which is very hot in automotive electron research field. I. -
Simplifying Current Sensing (Rev. A)
Simplifying Current Sensing How to design with current sense amplifiers Table of contents Introduction . 3 Chapter 4: Integrating the current-sensing signal chain Chapter 1: Current-sensing overview Integrating the current-sensing signal path . 40 Integrating the current-sense resistor . 42 How integrated-resistor current sensors simplify Integrated, current-sensing PCB designs . 4 analog-to-digital converter . 45 Shunt-based current-sensing solutions for BMS Enabling Precision Current Sensing Designs with applications in HEVs and EVs . 6 Non-Ratiometric Magnetic Current Sensors . 48 Common uses for multichannel current monitoring . 9 Power and energy monitoring with digital Chapter 5: Wide VIN and isolated current sensors . 11 current measurement 12-V Battery Monitoring in an Automotive Module . 14 Simplifying voltage and current measurements in Interfacing a differential-output (isolated) amplifier battery test equipment . 17 to a single-ended-input ADC . 50 Extending beyond the maximum common-mode range of discrete current-sense amplifiers . 52 Chapter 2: Out-of-range current measurements Low-Drift, Precision, In-Line Isolated Magnetic Motor Current Measurements . 55 Measuring current to detect out-of-range conditions . 20 Monitoring current for multiple out-of-range Authors: conditions . 22 Scott Hill, Dennis Hudgins, Arjun Prakash, Greg Hupp, High-side motor current monitoring for overcurrent protection . 25 Scott Vestal, Alex Smith, Leaphar Castro, Kevin Zhang, Maka Luo, Raphael Puzio, Kurt Eckles, Guang Zhou, Chapter 3: Current sensing in Stephen Loveless, Peter Iliya switching systems Low-drift, precision, in-line motor current measurements with enhanced PWM rejection . 28 High-side drive, high-side solenoid monitor with PWM rejection . 30 Current-mode control in switching power supplies . -
Integrated Switch Current Sensor for Shortcircuit Protection and Current Control of 1.7-Kv Sic MOSFET Modules
Integrated Switch Current Sensor for Shortcircuit Protection and Current Control of 1.7-kV SiC MOSFET Modules Jun Wang, Zhiyu Shen, Rolando Burgos, Dushan Boroyevich Center for Power Electronics Systems Virginia Polytechnic Institute and State Blacksburg, VA 24061, USA [email protected] Abstract—This paper presents design and implementations of a switch current sensor based on Rogowski coils. The current sensor is designed to address the issue of using desaturation circuit to protect the SiC MOSFET during shortcircuit. Specifications are given to meet the application requirement for SiC MOSFETs. It is also designed for high accuracy and high bandwidth for converter current control. PCB-based winding and shielding layout is proposed to minimize the noises caused by the high dv/dt at switching. The coil on PCB are modeled by impedance measurement, thus the bandwidth of coil is calculated. At the end, various test results are demonstrated to validate the great performance of the switch current sensor. Fig. 1. Output characteristics comparison: Si IGBT vs. SiC MOSFET Keywords—current sensing; Rogowski; SiC MOSFET; shortcircuit; current control I. INTRODUCTION SiC MOSFET, as a wide-bandgap device, has superior performance for its high breakdown electric field, low on-state resistance, fast switching speed and high working temperature [1]. High switching speed enables high switching frequency, which improves the power density of high power converters. The gradual cost reduction and packaging advancement bring a Fig. 2. Principle shortcircuit current comparison: Si IGBT vs. SiC MOSFET promising trend of replacing the conventional Si IGBTs with SiC MOSFET modules in high power applications. quickly and reaches its saturation value, where the VCE hits the Shortcircuit protection is one of the major challenges protection threshold value (“Fault detection” in the Fig.1). -
Accelerometers
JOHNS HOPKINS UNIVERSITY,PHYSICSAND ASTRONOMY AS.173.111 – GENERAL PHYSICS LABORATORY I Accelerometers 1L EARNING OBJECTIVES At the conclusion of this activity you should be able to: • Use your smartphone to collect acceleration data. • Use measured acceleration to estimate the distance of a free fall • Use measured acceleration to estimate kinematic quantities that describe an elevator ride. 2B ACKGROUND 2.1A CCELERATION,VELOCITY, AND POSITION We know from Classical Mechanics that we can move between position, velocity, and acceleration by repeatedly taking time derivatives of the position of an object. Similarly, starting from acceleration, we can take subsequent integrals with respect to time to obtain velocity and position respectively. Description Differential Form Integral Form Z Position ~x ~x ~vdt Æ d~x Z Velocity ~v ~v ~adt Æ dt Æ d 2~x d~v Acceleration ~a ~a Æ dt 2 Æ dt 2.2C OLLECTING DATA WITH A SMARTPHONE Most modern smart phones come packed with sensors that make them ideal to use as physics instru- ments. Many cell phones come packaged with an air pressure sensor, light meter, 3-axis accelerometers, 3-axis magnetometer, gyroscope, and of course a microphone. Many great physics measurements can be made using your smart phone. Several apps exist for collecting data from these packaged sensors. For this lab activity, we will use the PhyPhox app. You may download the app to your phone here: https://phyphox.org/ Revised: Wednesday 10th March, 2021 16:32 ©2014 J. Reid Mumford PhyPhox is also available in both the Google Play and Apple app stores. 2.3A CCELEROMETERS Your smartphone is packaged with a small integrated circuit package called a Microelectromechanical Systems (MEMS).