Freescale rolls MEMS pressure sensor
R Colin Johnson
6/22/2011 12:01 AM EDT
SAN ANTONIO, Texas—MEMS pressure sensors promise to be the next must-have component for smartphones and touchscreen tablets, because they impart the ability to determine altitude for next-generation location-based services—such as ascertaining what floor you are on in the mall—according to Freescale Semiconductor Inc., which announced a new low-cost Xtrinsic pressure sensor for consumer devices at the Freescale Technology Forum.
"MEMS sensors are not just for human-machine interfaces anymore," said Wayne Chavez, operations manager for consumer and industrial sensors at Freescale (Austin, Texas), in reference to the use of MEMS accelerometers to change a smartphone's orientation from portrait to landscape. "Our new Xtrinsic pressure sensor uses smart algorithms to derive altitude from barometric pressure readings, to locate pedestrians for both location based services, and for safety applications, like e911, where authorities might want to find people who are in trouble, perhaps even unconscious."
Freescale's Xtrinsic pressure sensor uses a proprietary piezoresistive MEMS process to achieve high-accuracy and low-power operation at a price affordable for mobile consumer device makers, the company claims. Smart algorithms combine with hardware acceleration, such as a built in first-in-first-out (FIFO) queue that extends battery life by allowing an application processor to access it at its leisure, instead of constantly polling it.
The Xtrinsic MPL3115A2 pressure sensor works at altitudes ranging from -600 to +6000 meters (-1968 to +19,685 feet) with built-in compensation for both temperatures and altitude, making it suitable for medical applications like respirators too, said Chavez.
The two-chip solution—a piezoresistive MEMS transducer wire-bonded to an ASIC in the same package, is packaged in an LGA capped with a gel-coated lid and consumes just two to 8.5 microamps in standby and low-power modes, respectively.
Freescale's smart Xtrinsic components combine a sensor with smart algorithms that simplify system integration.