The System Aspects of SensingThe System Aspects of Sensing

The short list of system aspects includes interfacing, communication (including wireless), packaging and ease of use. As the author of IC Insights' annual “Optoelectronics, Sensor/Actuator and Discrete (O-S-D) Report,” where he annually addresses market forecasts as well as technology trends, Rob Lineback has a unique view on what is happening in the sensor areas, especially where microelectromechanical systems (MEMS) and thin-film semiconductor technology is involved. He discussed the increasing focus on the system aspects of sensors with Design News.

Is there another system aspect that should be included in the list?

I would include the cost issue. Designers are being asked to be aware of what the cost might be, especially if something is going into manufacturing in any kind of volume. Also, system level test of some sort (is important), where the product can be easily debugged during design and even tested in manufacturing. The ability to reprogram or to reconfigure a design platform for various iterations or versions of a product for various price points in the market place, as well as geographical markets, is another one.

Have you observed any major transitions in MEMS sensing?

For a long time, the emphasis was mainly talking about all the fantastic things that could be done with MEMS-based sensors and thin-film-based sensors and a lot of the attention was placed on the amazing manufacturing capabilities to make these devices. Now, the focus is more and more from a component level — essentially, a part that is used to produce a piece of equipment. I think that is a real big change in the way a lot of these technologies are being handled right now.

Is one sensor type more likely to have more system-level integration orapplication-specific packaging?

I think the accelerometers are definitely at the forefront when it comes to having multi-sensing capability packed into the package. Also, multi-die or chip solutions, much more application-specific functions, are built into these accelerometers for handheld devices for human interface control, where you shake it or you tap it, like an MP3 player or a cell phone and then also freefall detection, in case you drop it, it will actually shut down the hard drive or do different things to protect itself. I think we are seeing the accelerometer really being at the forefront when it comes to being tailored and having application-specific functions, low-cost packaging and other things in order to hit the price target in a small size that is required for the applications that are going after these types of devices.

Is there such a thing as a plug-and-play sensor today?

The integration level in the sensor products has reached a point where the need for actually interfacing directly to the sensor has become less and less of a factor. What you are really interfacing to is the electronics side, since the microcontroller and the A-to-D and even the wireless transmitters are actually inside these packages now. It is really becoming a subsystem, more than it is a sensor. The sensor is embedded inside the package. That, in some ways, has made it easier to do what could be thought of as plug-and-play — but the plug-and-play is really just plugging and playing with another integrated circuit that is connected to the serial bus and no longer worrying about the specific sensor part that is inside the package.