A digital three-axis iMEMS(R) smart motion sensor (ADXL345) from Analog Devices is a small, ultra-low-power, high-resolution accelerometer for measuring tilt, shock and acceleration. The sensor can operate at a primary supply voltage down to 1.8V and offers high-resolution measurements (4 mg/LSB) which, for example, can detect inclination changes as small as 0.25 degree.
New features added to portable devices, handheld instruments and battery-operated medical and industrial electronic devices tax already stressed power and space allotments. To address growing demand for motion-enabled features, Analog Devices engineers developed the ADXL345 for use in mobile gaming systems, cell phones, digital still cameras and other battery-operated electronics. The smart sensor also features a 10,000g shock rating, making it well-suited for applications such as hard-disk drive protection in personal computers.
The ADXL345 has an output data range that scales from 0.1 Hz to 3.2 kHz, unlike competing devices, which offer fixed 100-Hz, 400-Hz or 1-kHz data rates. 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 1,600 Hz bandwidth down to 25 uA under 10 Hz. The device modulates power consumption automatically in proportion to its output data rate and automatically switches to a sleep mode during periods of inactivity.
The unit consumes as little as 25 microamps and provides 13-bit resolution. It features an on-chip FIFO (first-in/first-out) memory block that stores up to 32 sample sets of X, Y and Z data and saves power by off-loading that function from the host processor. For more information, go tohttp://designnews.hotims.com/27742-540.