- ADI’s ADXL346 digital three-axis iMEMS® smart motion sensor features resolution up to 13-bits and an embedded FIFO that enables significant overall system power savings by managing host processor power.

Norwood, MA (03/31/2009) - Every new feature introduced to a portable device, handheld instrument, and other battery-operated medical and industrial electronic devices taxes already stressed power budgets. To address the growing demand for more motion-enabled features, Analog Devices, Inc. (ADI) has developed a new family of smart motion sensors specifically for power- and space-constrained portable devices. The ADXL346 digital three-axis iMEMS® smart motion sensor is ADI's latest offering in this new class of small, ultra lower-power, high-resolution iMEMS® accelerometers for measuring tilt, shock, and acceleration. Designed to operate at a primary supply voltage down to 1.8-V, these new motion sensors, first introduced at the Consumer Electronics Show in January, are capable of high resolution (4 mg/LSB) which enables, for example, measurement of inclination changes as little as 0.25 degrees.

Within the ADXL346’s small 3mm x 3mm x 0.95mm footprint, is a complete three-axis “smart” motion measurement system with selectable measurement ranges. The ADXL346 measures both dynamic acceleration resulting from motion or shock and static acceleration, such as gravity, which allows it to be used as a tilt sensor. The device automatically modulates its power consumption in proportion to its output data rate as well as saves additional power by automatically switching to a sleep mode during periods of inactivity. For even more power savings, a standby mode can also be used.

“Motion sensing has moved beyond the initial concept of just acceleration and now includes tilt, shock, vibration, and rotation,” said Bill Murphy, product line director for Micromachined Products, Analog Devices. “The cost effective measurement of these forces while consuming very little of the power budget has enabled a new wave of innovative product features and capabilities.”

The ADXL346 features an on-chip FIFO (first-in/first-out) memory block that stores up to 32 sample sets of X-, Y-, and Z-axis data and effectively off-loads the FIFO function from the host processor. This allows the host processor and other power hungry peripherals to go into a sleep mode until needed saving significant system power. Effective use of this feature can dramatically decrease overall power usage by up to 75 percent.

More About the ADXL346
The ultra-low-power ADXL346 digital accelerometer has wide, selectable bandwidth of 0.1 Hz to 1600 Hz, unlike competing 1.8 V capable accelerometers which have a maximum bandwidth of 100 Hz. This allows portable system designers to build very responsive, real time embedded systems that provide the user experience that’s in demand. Power consumption ranges from less than 150 uA at 1600 Hz bandwidth down to 25 uA under 10 Hz. The ADXL346 also measures dynamic acceleration with ±2g/4g/8g/16g user-selectable measurement ranges resulting from motion or shock and also includes built in orientation sensing via simple register reads.

Several special sensing functions are also programmed on-chip along with user-programmable threshold levels. Activity and inactivity sensing detect the presence of or lack of motion or if the acceleration on any axis exceeds a user-set level. A tap sensing function detects single and double taps. Free-fall sensing detects if the device is falling. These functions can be mapped to one of two interrupt output pins. In addition, the new accelerometer includes I²C and three- and four-wire SPI (serial peripheral interface) digital interfaces.

Product Availability
The ADXL346 digital three-axis iMEMS accelerometer is available today in sample quantities with volume production scheduled for August 2009. The ADXL346 comes in a small, thin 3mm x 3mm x 0.95mm 16-lead LGA package and is priced at $3.04 per unit in 1,000-unit quantities. For more information, visit

ADI’s iMEMS® Accelerometer Technology
In the early 1990s, Analog Devices revolutionized automotive airbag systems with its unique iMEMS® (integrated Micro Electro Mechanical System) technology. ADI’s iMEMS accelerometers are the first devices to integrate a small, reliable MEMS sensor structure with advanced signal conditioning circuitry into a single IC solution. Today, ADI offers the industry's broadest accelerometer portfolio available in 1-, 2- and 3-axis configurations and in low-g or high-g sensing ranges. iMEMS accelerometers address the high-performance, low-power, integrated functionality, and small size requirements in countless automotive, consumer product and industrial applications. ADI’s iSensor® accelerometers go further by adding application targeted functionality, factory calibration, and programmability, all in a single small package.

About Analog Devices

Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the longest standing, highest growth companies within the technology sector. Acknowledged industry-wide as the world leader in data conversion and signal conditioning technology, Analog Devices serves over 60,000 customers, representing virtually all types of electronic equipment. Analog Devices is headquartered in Norwood, Massachusetts, with design and manufacturing facilities throughout the world. Analog Devices is included in the S&P 500 Index.

iMEMS and iSensor are registered trademarks of Analog Devices, Inc.

Editor's Contact Information:

Howard Wisniowski

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