The broad benefit of MEMS technology is that it will allow high-volume, small-package technology and batch semiconductor manufacturing to replace the complex manufacturing processes associated with quartz. Since the final product is a silicon die, MEMS can be co-packaged (overmolded) with associated ICs, enabling further benefits in manufacturability, size, compatibly, ease-of-use, and, of course, lower total system cost. Finally, MEMS is more immune to shock, vibration, and electromagnetic interference (EMI) than quartz; can be designed to be free of “activity dips”; and can support operating temperature ranges beyond -40°C to +85°C. (by Todd Borkowski)
Time for a change: Quartz oscillators make way for MEMS - [Link]
This is a collection of Maxim’s newest real-time clock ICs.
This real-time clock IC operates with very low current and is compatible with high-ESR crystals for a space saving, low-cost design. Read the rest of this entry »
Epson has combined the reliability of quartz crystals with the tiny dimensions of MEMS devices to create a tiny high-resolution six degree-of-freedom inertial measurement unit that can track motion for everything from aerospace to oil-well drilling. [via]
Epson Downsizes Inertial Measurement Units - [Link]
ST Microelectronics has introduced what it is calling the world’s smallest digital e-compass — a three-axis magnetometer combined with a three-axis accelerometer on a 2x2mm MEMS chip.
By saving board space on next-generation mobile devices, this device should enable new ultra-miniature, location-aware applications. Micro-electromechanical systems already provide much of the smarts to smartphones, and ST is already a major supplier for devices from Apple’s iPhone to Samsung’s Galaxy. However, a new generation of smartphones and other personal devices will have even less board space.
ST said in a press release that its new LSM303C is 20 percent smaller than previous models, saving just under a square millimeter of board space. That does not seem like much, but it will be welcome for devices such as smartwatches or monitoring bracelets, where space is especially precious.
ST Introduces Smallest MEMS Compass - [Link]
TempFlat MEMS Eliminates Temperature Compensation. Steve Taranovich writes:
SiTime Corporation has introduced the TempFlat MEMS. Until recently, all MEMS oscillators used compensation circuitry to stabilize the output frequency over temperature. This new design eliminates temperature compensation, resulting in higher performance, smaller size, lower power and cost. The basic architecture of a MEMS oscillator combines a MEMS resonator die together with an oscillator IC. As shown on the left side of the diagrams below, SiTime has developed different types of MEMS resonators for different applications needs.
SiTime’s MEMS Resonators: An alternative to Quartz - [Link]
According to researchers at the Swedish Royal Institute of Technology (KTH) in Stockholm, graphene can increase the sensitivity of micro-electromechanical system (MEMS) sensors by up to 100 times due to exteme thinness of graphene films compared to other piezoresistive materials.
Piezoresistive pressure sensors typically integrate silicon piezoresistors into sensor membranes so that strain can be read in terms of resistance. The MEMS version suspends the membrane over a cavity by etching out the underying silicon dioxide. In the KTH version, an extremely thin layer of graphene is suspended over a cavity etched into a silicon dioxide layer on a silicon substrate. The extreme thinness of the graphene membrane – less than a nanometer with a monolayer membrane – increases the sensitivity of the electromechanical effect. [via]
Graphene Beats Silicon in Strain Gauges - [Link]
by Steve Taranovich
The following is a white paper by Silicon Labs with an innovative new process and technology that I believe deserves some level of detail and explanation for informative and educational purposes for EDN readers. Learning about this technology will help all designers give birth to new ideas and architectures as well as help those other designers to effectively integrate this type of product into their systems,
CMEMS® technology is an innovative CMOS + MEMS manufacturing process developed by Silicon Labs, a leading supplier of timing solutions. The term CMEMS is a contraction of the acronyms CMOS and MEMS (microelectromechanical systems). CMEMS technology offers many benefits over traditional oscillator approaches, ranging from scalability, customer-specific programmability and 0-day samples, to long-term reliability and performance. This white paper describes CMEMS process technology, existing hybrid oscillator architectures and the Si501/2/3/4 (Si50x) CMEMS oscillator architecture.
CMEMS oscillator architecture - [Link]
New Si50x CMEMS® Oscillators Leap Ahead of Quartz-Based Timing Devices with Superior Frequency Stability, Reliability and Programmability
Silicon Labs has developed a new low-drift, single-die MEMS oscillator fabricated using a CMOS process. By porting low-temperature MEMS technology to the SMIC foundry, they managed to build a SiGe structure on top of the passivation layer of a CMOS logic chip using an existing CMOS production line. The drift problems of dual-die devices are eliminated by selecting specific materials to counteract thermal drift. The programmable oscillators operate at up to 100 MHz with frequency stability down to 20 ppm. Higher speed devices are planned, according to a Silicon Labs’ source.
CMOS MEMS (CMEMS) technology allows data sheet performance for frequency stability to be guaranteed for ten years, including solder shift, load pulling, supply voltage variation, operating temperature range, vibration and shock. This is ten times longer than typically offered by comparable crystal and MEMS oscillators. The oscillators tightly couple the MEMS resonator with CMOS temperature sensing and compensation circuitry, ensuring a highly stable frequency output despite thermal transients and over the full industrial temperature range. [via]
New MEMS Oscillators Boast Long-term Stability - [Link]
The C10988MA-01 sensor from Hamamatsu Photonics is an ultra-compact spectrometer built with Micro-Opto-Electro-Mechanical Systems (MOEMS) technology. Measuring only 27.6 x 13 x 16.8 mm and weighing just 9 grams, the device is intended to be used in portable and hand-held devices where a standard mini-spectrometer would be too large and consume too much power. [via]
The new device features an aberration-corrected concave grating with a very short focal length and blazed grating profile for high diffraction efficiency. The grating is replicated onto a convex glass lens using nano-print technology. Directly opposite the grating there is a dedicated CMOS silicon image sensor with an on-chip slit. This 75 x 750 µm slit is formed in the CMOS chip using MEMS technology. The distance between the sensor and slit is only 1 mm, and the distance between the grating and the image sensor distance a mere 8.5mm. Thanks to its novel design, the sensor offers a spectral resolution of 14 nm in the wavelength range of 340 to 750 nm, making it suitable for a variety of visible light applications requiring a miniaturized spectrometer head.
Ultra-Compact Spectrometer Sensor Targets Visible Light - [Link]