3-Axis, ±2 /±4 /±8 /±16 Ultralow Power Digital Accelerometer

The ADXL344 is a versatile 3-axis, digital-output, low g MEMS accelerometer. Selectable measurement range and bandwidth and configurable, built-in motion detection make it suitable for sensing acceleration in a wide variety of applications. Robustness to 10,000 g of shock and a wide temperature range (−40°C to +85°C) enable use of the accelerometer even in harsh environments.

The ADXL344 measures acceleration with high resolution (13-bit) measurement at up to ±16 g. Digital output data is formatted as 16-bit twos complement and is accessible through either a SPI (3- or 4-wire) or I2C digital interface. The ADXL344 can measure the static acceleration of gravity in tilt-sensing applications, as well as dynamic acceleration resulting from motion or shock. Its high resolution (3.9 mg/LSB) enables measurement of inclination changes less than 1.0°.

Several special sensing functions are provided. Activity and inactivity sensing detect the presence or lack of motion. Tap sensing detects single and double taps in any direction. Free-fall sensing detects if the device is falling. Orientation detection reports four- and six-position orientation and can trigger an interrupt upon change in orientation. These functions can be mapped individually to either of two interrupt output pins.

An integrated memory management system with a 32-level first in, first out (FIFO) buffer can be used to store data to minimize host processor activity and lower overall system power consumption.

The ADXL344 is supplied in a small, thin, 3 mm × 3 mm × 0.95 mm, 16-terminal, plastic package.

APPLICATIONS

* Handsets

* Gaming and pointing devices

* Personal navigation devices

* Hard disk drive (HDD) protection

* Multipurpose accelerometer with 10- to 13-bit resolution for use in a wide variety of applications

* Digital output accessible via SPI (3- and 4-wire) and I2C

* Built-in motion detection features make tap, double-tap, activity, inactivity, orientation, and free-fall detection trivial user-adjustable thresholds interrupts independently mappable to two interrupt pins