The Zen of Sensor Design

Contributed by Mike Stanley

Originally posted on Freescale’s Smart Mobile Devices Embedded Beat Blog

About two years ago, I joined the Freescale sensors team, which focuses on accelerometers, pressure sensors, and touch sensors.

Prior to that, I spent a number of years in the Freescale’s microcontroller solutions group, where I was an architect for several digital signal controller and microcontroller product families. One of the first things I learned when I moved into the sensors group was that certain “rules of the game” that relate to microcontroller design needed to be adapted when dealing with sensors. An example is package selection. With most microcontrollers, package selection is based upon number of functional and power pins required, PCB assembly processes targeted and (sometimes) thermal characteristics. Performance considerations are often secondary, if they exist at all. Sensors interact with the real world. Mechanical stresses introduced during both package assembly and PCB mounting can affect electrical performance of the device; often showing up as additional offset or variation of performance with temperature. Even the compound used for die attach has a demonstrable effect on sensor performance, and must be considered early in the design process. Continue reading

Evolving Intelligence with Sensors

Contributed by Michael Stanley, Freescale Semiconductor

Originally posted on Freescale’s Smart Mobile Devices Embedded Beat blog

I’ve always been fascinated by electronic sensors. The idea of being able to measure and interact with the physical world appeals to the ten-year-old inside me. Not so long ago, if you needed to measure some physical quantity as an input to your system, you bought an analog sensor, hooked up your own signal conditioning circuitry, and fed the result into a dedicated analog-to-digital converter. Over time, engineers demanded, and got, self-contained products which handled those signal conditioning and conversion tasks for them. Continue reading

iSuppli: Silicon Magnetic Sensors Head for Big Time

Contributed by Richard Dixon, Senior Analyst MEMS, iSuppli

Introduction

Back in February 2009 the iSuppli MEMS and sensor team reported on trends in the automotive magnetic sensor market, and has since completed a comprehensive report on the whole market for silicon magnetic sensor elements and ICs – predominantly Hall, asymmetric magnetoresistive (AMR) and giant magnetoresistive (GMR) based devices. This article provides the cliff notes of our special report and briefly compares different technologies and highlights just some of the many applications for this very pervasive sensor.

Where do these sensors play? The fields are broad and include:

  • High-cost applications like industrial motors that require accurate knowledge of rotor position to control loads
  • Mid-priced automotive sensor ICs that measure rotation speed angle, and position
  • Low-cost consumer and mobile phone products

Continue reading

MEMS Gyros Poised to Redefine the Smartphone

EETimes writer R. Colin Johnson has posted an excellent article on MEMS manufacturer InvenSense’s foray into the smartphone market. (For more on MEMS gyros taking off, see Colin’s article, “Five Apps That Will Make 2010 the Year of the Gyroscope” in Smarter Technology.)

The article notes:

  • Estimated at $115 billion, the smartphone market is very lucrative for MEMS makers like InvenSense.
  • InvenSense CEO Steven Nasiri was quoted as estimating “that in less than two years, every phone will be a smartphone with a camera, WiFi, Bluetooth and email.”
  • InvenSense’s new 3-axis gyro integrates with an accelerometer to provide new user interface functionality for the apps that smartphone users demand, such as gaming and music applications.

It will be interesting to see if Apple’s rumored tablet computer (to be announced today at a special event in San Francisco) will incorporate any gyros into its user interface. (Isn’t a tablet computer essentially a bigger smartphone?)

Read Colin’s full article here and check out his blog on next generation electronics–NextGenLog–as well.

MEMS at CES 2010: Pico projectors, low-power displays, hands-free user interface & more

There have been some really exciting announcements for the MEMS community coming out of CES 2010. Here are four that stuck out:

  • Microvision SHOWWXMicrovision is generating a lot of buzz with its SHOWWX™ Laser Pico Projector. Based on proprietary MEMS single scanning mirror technology, Microvision’s pico projector can turn a mobile device into a platform for projecting high-quality video.  And the best part is that the SHOWWX™ will be commercially available very soon in the US. More info is available on Microvision’s Displayground blog.
  • New accelerometers from STMicroelectronics – MEMS device maker STMicroelectronics is exhibiting its next generation of accelerometers. The new accelerometers’ main advantages include a smaller footprint, lower power consumption, and a host of feature enhancements.
  • Qualcomm’s mirasol® e-reader prototypeQualcomm MEMS Technologies (QMT) is demoing a prototype of an e-reader using its mirasol® display technology. What separates mirasol® from other display technologies is its use of available ambient light instead of standard backlighting. Bonus points to QMT for not only creating a highly-readable color display, but making it use less power too.
  • The hands-free user interfaceZyxio, which calls itself a human media interaction company, is touting its sensawaft™ technology that uses a MEMS sensor to translate human breaths into computer instructions. The company also held a “Be a Mind Blower” competition for people to imagine products incorporating sensawaft™ technology. The winners then get to work with Zyxio to develop their ideas into real products.
    Continue reading