Smallest Sensor Week: Smallest 3-Axis Digital Gyroscope
December 12, 2011 by Randy Frank
Filed under Featured, Gyroscope, MEMS Sensor Technology
With microelectromechanical system (MEMS) technology and semiconductor packages, sensor manufacturers compete to cram the most technology into the smallest package. This week, Sensor Tips will highlight products that the manufacturer says is the world’s smallest. Without performing the extensive research necessary to verify the claims, we’ll take their word for it. Users can take advantage of these products’ minute size and capabilities to add features and performance to portable electronic products.
The first smallest sensor is STMicroelectronics world’s smallest 3-axis digital gyroscope. Housed in a 3 x 3.5 x 1-mm land grid array (LGA) 16-pin package, the L3G3200D gyroscope provides a 16-bit data output on the interrupt and data-ready lines and it integrates low- and high-pass filters with user-selectable bandwidth. The gyro operates with any supply voltage within the range of 2.4 to 3.6V with selectable full-scale values of ±250/500/2000 dps.
For more information about STMicroelectronics L3G3200D 3-axis digital gyroscope, click here.
STMicroelectronics’ Three MEMS Sensors Provide 10 DoF
May 18, 2011 by Randy Frank
Filed under Featured, Gyroscope, Magnetic sensor, MEMS Sensor Technology, Motion, Pressure
If a single MEMS sensor is good, a system that provides 10 degrees of freedom (DoF) should be an order of magnitude better.
The three ST MEMS sensors include a geo-magnetic module, a gyroscope, and a pressure sensor. With these sensors, a consumer device can provide a complete indication of its linear acceleration, angular velocity, earth gravity, heading and altitude. The sensors provide three axes of linear motion, three axes of angular motion, three axes of magnetic motion and an altitude axis resulting in ten degrees of freedom (DoF).
In a 3 x 5 x 1mm package, the LSM303DLHC geo-magnetic module integrates three-axis sensing of linear and magnetic motion.
In a 4 x 4 x 1-mm package, the L3G4200D three-axis digital gyroscope provides output accuracy and stability over temperature and time.
While it is only available now in the 10-DoF sensor solution for evaluation, the pressure sensor provides the altimeter portion of the system. In a 3 x 3 x 1-mm package, the device has an operating pressure range of 260 – 1260 millibars. This corresponds to the atmospheric pressures between -700 and +10000m relative to sea level.
MEMS-Based Gas Meter Flow Sensors
November 30, 2010 by Randy Frank
Filed under Accelerometer, Featured, Flow
Experts predict that gas meters are poised to undergo the same change as electricity meters for smarter, remote meter reading. In response, STMicroelectronics and Omron have collaborated to provide a complete solution for electronic gas meter flow sensors. The design uses an Omron transducer and a companion analog front-end chip developed by ST. The resulting flow sensor incorporates a MEMS (Micro-Electro-Mechanical Systems) micro-thermal sensor technology and is intrinsically compensated for both temperature and pressure variations. A built-in circuit compensates for the variation of multiple gas composition.
Mounted on a small PCB (Printed-Circuit-Board) measuring 7.2×8.6 cm, the gas-flow sensor provides high accuracy with very low power consumption. The unit also has built-in motor drivers for valve control and protection against temperature and vibration effects. The sensor board uses the STLM20 temperature sensor and the LIS332AR accelerometer as well as an ultra-low power STM8L152 microcontroller with 32 Kbytes of flash memory and an LCD display driver.
For more information on the electronic gas meter flow sensors, click here.
Accelerometer Targets Advanced Automotive Airbag Applications
November 12, 2010 by Randy Frank
Filed under Accelerometer, Featured, MEMS Sensor Technology
Accelerometers for automotive airbag systems showcased the potential for microelectromechanical system (MEMS) sensors when they were first introduced almost two decades ago. With airbags standard on US and other regions’ vehicles, and several sensors used in these systems, the application continues to spawn product advancements. Most recently, STMicroelectronics introduced a new family of high-g acceleration sensors for advanced airbag systems. Housed in a 16-pin SOIC, the digital output of the AIS1xxxDS accelerometers provides single-axis in-plane motion sensing across five full-scale ranges, from ±20 g up to ±400 g. The digital output conforms to the Distributed Systems Interface (DSI) protocol developed to interconnect sensors and actuators in automotive airbags systems.
For more information about STMicroelectronics AIS1xxxDS accelerometers, click here.
One-Touch Sensor Improves Stylists on Various Products
May 6, 2010 by admin
Filed under Touch Sensing
Housed in a tiny 8-pin package, the STM8T141 touch-sensor controller from STMicroelectronics can improve the performance and styling of products, such as mobile phones, portable consumer products, and appliances. The IC allows the replacement of conventional buttons with a touch sensor for main power-on/off or to trigger wake-up from battery-saving sleep modes.
The STM8T141 draws a current as low as 11 µA from the battery and can detect user presence via the touch-sensor electrode, responding quickly to wake the system from a low-power sleep mode. It monitors a single touch-sensing electrode embedded on the control panel of an end-product or in the outer casing. The sensor can be hidden, or its position indicated using a printed, overlaid, or illuminated icon.
The device also supports proximity sensing, allowing equipment to be controlled without direct contact from the user. This allows the sensor to control power-saving features, such a system wake-up on user detection, or features for added convenience, like automatic backlight activation supporting find-in-the-dark capability.
Other features include self-calibration, automatic recalibration, and environmental compensation filtering. The chip supports a driven electrode-shielding wire, which protects against noise from external sources without the reduction in electrode sensitivity experienced with a grounded shield.
A number of development tools are available for the touch-sensor IC. An evaluation kit demonstrates the chip’s touch and proximity features, while the ST-TSLINK programming dongle and STM8T14X-SB socket programming board are used with the STVP PC-based programming tools for product configuration.
The STM8T141 is sampling to lead customers in the 3x2x0.6-mm ultra-small and low-profile DFN8 package and is now in volume production. High volumes are available immediately in a narrow variant of the SO-8 package, priced at $0.45 in quantities of 10,000.
“Smart” Contact Lens Promises To Detect Glaucoma Earlier
STMicroelectronics will develop and supply a wireless MEMS sensor that acts as a transducer, antenna and mechanical support for additional read-out electronics in a breakthrough platform developed by Swiss company Sensimed AG. This solution will enable better management of glaucoma patients via earlier diagnosis and treatment that is optimally tailored to the individual patient.
Known as the SENSIMED Triggerfish®, the solution is based on a “smart” contact lens that uses a tiny embedded strain gauge to monitor the curvature of the eye over a period of, typically, 24 hours, providing valuable disease management data that is not currently obtainable using conventional ophthalmic equipment.
Glaucoma(3), the second most common cause of blindness around the world, is an irreversible progressive disease of the optic nerve that can eventually lead to blindness. Â Although it cannot be cured, its progress can be controlled once it is diagnosed and treated properly. The standard test is the measurement of intraocular pressure (IOP), using an instrument known as a tonometer, during periodic visits to an ophthalmologist. However, the tonometer may fail to detect an elevated IOP, especially in glaucoma patients, because the pressure varies during the day and often peaks during sleep or outside of office hours. As a result, the disease is often diagnosed only after significant damage to the optic nerve has already occurred, and the disease keeps progressing in many patients due to inadequate treatment.
Sensimed’s ingenious solution is a two-part system comprising the smart contact lens and a small receiver worn around the patient’s neck. Â In addition to the strain gauge the lens contains an antenna, a tiny dedicated processing circuit and an RF transmitter to communicate the measurements to the receiver. The lens is powered via the received radio waves and does not need to be connected to a battery. The embedded components are positioned in the lens in such a way that they do not interfere with the patient’s vision. The lens is fitted by the ophthalmologist and when the patient returns the next day the ophthalmologist removes the lens and receiver, obtaining a complete record of IOP changes over the preceding 24 hours.
The SENSIMED Triggerfish® has obtained the CE mark(4), is currently running numerous application trials, and is commercially available in selected centers.  ”The device is easy to use and has facilitated and improved patient care substantially,” said Dr.Kaweh Mansouri who has been using the Triggerfish at the University Hospital, Geneva, Switzerland.
ST engineers are now working with Sensimed to translate this breakthrough technology into a reliable commercial MEMS product ready for mass production. ST expects the development of the MEMS sensor to be completed in Q2 2010 and manufacturing to start in Q3 2010, with availability outside trials to doctors and patients subject to regulatory approvals. Sensimed and ST anticipate progressively rolling out the product country-by-country across Europe beginning in Q3 and entering the US market by the end of 2011.
Multi-Touch ‘Resistive’ Touchscreen Controller Chip
As the latest high-tech devices such as smartphones, mobile internet devices and netbooks adopt multi-touch touchscreens to support increasingly sophisticated ‘apps’ and games,STMicroelectronics has introduced a multi-touch ‘resistive’ touchscreen controller chip to optimize the Bill of Materials of the electronics supporting this advanced capability. The STM32TS60 is the first member of ST’s new STMTouch family, which offers a broad portfolio of solutions including multi-touch devices and proximity and touch-key sensors.
The new multi-touch controller detects up to ten simultaneous touches with fingers, nails or stylus, enabling application designers to replace complex menu sequences with more direct and natural user controls. Actions made easier with multi-touch capabilities include browsing and selecting options, handwriting and data entry, arranging and sizing windows, picking up and dragging images, and fast and intuitive game play. Other abilities include drawing pictures, using touch pressure to adjust line thickness.
Employing resistive touch-panel technology, the STM32TS60 controller offers customers a real alternative and complements the recent industry trend for using capacitive touch technology. Resistive technology is a cost effective and mature high-volume solution that has seen dramatically improved performance over the past few years in terms of durability and display transparency. In addition, it easily overcomes EMI (electromagnetic interference) noise issues, which can be an inherent limitation with alternative touch technologies. Resistive technology is already widely used in PDAs and similar touch-enabled devices and the screens are readily available in standard LCD sizes and at competitive prices.
The new chip combines the company’s STM32 microcontroller architecture with PMatrixTM Multi-Touch technology from ST‘s partner Stantum to achieve fast response times while minimizing system complexity and component count.
The STM32TS60 single-core microcontroller is an added-value solution compared to other expensive multi-core processor or digital signal processors (DSPs) requiring specialized programming expertise.
The STM32TS60’s high EMI immunity makes it suitable for use in multi-function wireless products such as cellphones, notebook PCs, netbooks and mobile Internet devices. Moreover, its low power consumption helps to maximize operating times and recharge intervals, and is a direct benefit of the STM32’s energy-saving design features and ARM® Cortex™-M3 processor conceived for power-sensitive embedded applications. In addition, very-low-power idle mode with ‘wake-up on touch only’ helps further extend mobile battery life.
The STM32TS60 is housed in a 7 x 7mm 144-pin UFBGA package, and is now sampling to lead customers. Volume production is expected for Q2 2010.
3-Axis Gyroscope Provides 360° Detection
STMicroelectronics has introduced a high performance single-package analog gyroscope that accurately measures angular rates along three orthogonal axes. Combining superior accuracy with high stability and a small size, ST’s 3-axis gyroscope heralds the widespread adoption of realistic-motion user interfaces in all kinds of consumer applications.
The sensor provides 360° angular-rate detection for high-precision 3D gesture and motion recognition in mobile phones, game controllers, personal navigation systems and other portable devices. Combined with a 3-axis accelerometer, ST’s newest gyroscope enables the creation of Inertial Measurement Units, devices that track and deliver complete information on the type, rate, and direction of motion of humans, vehicles and other objects.
The innovative gyroscope provides two separate outputs for each of the three axes at the same time: a 400dps full-scale value for high accuracy of slow motion and a 1,600dps full-scale value to detect and measure very fast gestures and movements. The two simultaneous full-scale outputs, together with high resolution and excellent stability over an extended temperature range (from -40°C to 85°C) and over time, set new standards in precision, accuracy and stability, and simplify the sensor integration at both the software and hardware level.
ST’s 3-axis gyroscope can operate with any supply voltage in the range of 2.7 to 3.6V. Robust and resistant to mechanical stress, ST’s 3-axis gyroscope leverages the same manufacturing process that ST has already successfully applied to more than 600 million accelerometers sold in the market. “In 2003, ST was the first to deliver a 3-axis analog accelerometer in a single package,” said Benedetto Vigna, General Manager of STMicroelectronics’ MEMS and Healthcare division. “Now we are the first to have a 3X Analog Gyroscope.”
Samples of ST’s LYPR540AH 3-axis gyroscope, in a 4.4 x 7.5 x 1.1mm package, are available now, with volume production scheduled for Q1 2010. Unit pricing is $3.6 for volumes in the range of 10k.
