ADXL345 Datasheet, PDF (1/24 Pages) Analog Devices – Three-Axis, ±2/4/8/16g Digital Accelerometer

Preliminary Technical Data
Three-Axis, ±2/4/8/16g
Digital Accelerometer
ADXL345
FEATURES
GENERAL DESCRIPTION
Ultra low power: 25 to 130 µA at VS = 2.5 V (typ)
Power consumption scales automatically with bandwidth
User selectable fixed 10-bit resolution or 4mg/LSB scale
factor in all g-ranges, up to 13-bit resolution at ±16 g
32 level output data FIFO minimizes host processor load
Built in motion detection functions
The ADXL345 is a small, thin, low power, three-axis
accelerometer with high resolution (13-bit) measurement 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.
• Tap/Double Tap detection
• Activity/Inactivity monitoring
• Free-Fall detection
Supply and I/O voltage range: 1.8 V to 3.6 V
SPI (3 and 4 wire) and I²C digital interfaces
The ADXL345 is well suited for mobile device applications. It
measures the static acceleration of gravity in tilt-sensing
applications, as well as dynamic acceleration resulting from
motion or shock. Its high resolution (4mg/LSB) enables
resolution of inclination changes of as little as 0.25°.
Flexible interrupt modes – Any interrupt mappable to either
interrupt pin
Measurement ranges selectable via serial command
Bandwidth selectable via serial command
Wide temperature range (-40 to +85°C)
10,000 g shock survival
Pb free/RoHS compliant
Small and thin: 3 × 5 × 1 mm LGA package
Several special sensing functions are provided. Activity and
inactivity sensing detect the presence or lack of motion and if
the acceleration on any axis exceeds a user-set level. Tap sensing
detects single and double taps. Free-Fall sensing detects if the
device is falling. These functions can be mapped to interrupt
output pins. An integrated 32 level FIFO can be used to store
data to minimize host processor intervention.
APPLICATIONS
Low power modes enable intelligent motion-based power
management with threshold sensing and active acceleration
Handsets
measurement at extremely low power dissipation.
Gaming and pointing devices
Personal navigation devices
HDD protection
The ADXL345 is supplied in a small, thin 3 mm × 5 mm ×
1 mm, 14-lead, plastic package.
Fitness equipment
Digital cameras
FUNCTIONAL BLOCK DIAGRAM
Vs
V_DD I/O
POWER
MANAGEMENT
3 AXIS
SENSOR
SENSE
ELECTRONICS
DIGITAL
FILTER
CONTROL
AND
INTERRUPT
LOGIC
ADXL345
SERIAL I/O
COM
CS
Figure 1. ADXL345 Simplified Block Diagram
INT1
INT2
SDA/SDI/SDIO
SDO/ALT
ADDRESS
SCL/SCLK
Rev. PrA
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone]
©2008 Analog Devices, Inc. All rights reserved.