Datasheet ADXL345 (Analog Devices)

3-Axis, ±2 g/±4 g/±8 g/±16 g Digital Accelerometer Data Sheet ADXL345
FEATURES GENERAL DESCRIPTION Ultralow power: as low as 23 µA in measurement mode and
The ADXL345 is a small, thin, ultralow power, 3-axis accelerometer
0.1 µA in standby mode at VS = 2.5 V (typical)
with high resolution (13-bit) measurement at up to ±16 g. Digital
Power consumption scales automatically with bandwidth
output data is formatted as 16-bit twos complement and is acces-
User-selectable resolution
sible through either a SPI (3- or 4-wire) or I2C digital interface.
Fixed 10-bit resolution
The ADXL345 is well suited for mobile device applications. It
Full resolution, where resolution increases with g range,
measures the static acceleration of gravity in tilt-sensing appli-
up to 13-bit resolution at ±16 g (maintaining 4 mg/LSB
cations, as well as dynamic acceleration resulting from motion
scale factor in all g ranges)
or shock. Its high resolution (3.9 mg/LSB) enables measurement
Embedded memory management system with FIFO
of inclination changes less than 1.0°.
technology minimizes host processor load Single tap/double tap detection
Several special sensing functions are provided. Activity and
Activity/inactivity monitoring
inactivity sensing detect the presence or lack of motion by
Free-fall detection
comparing the acceleration on any axis with user-set thresholds.
Supply voltage range: 2.0 V to 3.6 V
Tap sensing detects single and double taps in any direction. Free-
I/O voltage range: 1.7 V to V
fall sensing detects if the device is falling. These functions can
S SPI (3- and 4-wire) and I2C digital interfaces
be mapped individually to either of two interrupt output pins.
Flexible interrupt modes mappable to either interrupt pin
An integrated memory management system with a 32-level first in,
Measurement ranges selectable via serial command
first out (FIFO) buffer can be used to store data to minimize host
Bandwidth selectable via serial command
processor activity and lower overall system power consumption.
Wide temperature range (−40°C to +85°C)
Low power modes enable intelligent motion-based power
10,000 g shock survival
management with threshold sensing and active acceleration
Pb free/RoHS compliant
measurement at extremely low power dissipation.
Small and thin: 3 mm × 5 mm × 1 mm LGA package
The ADXL345 is supplied in a small, thin, 3 mm × 5 mm × 1 mm,
APPLICATIONS
14-lead, plastic package.
Handsets Medical instrumentation Gaming and pointing devices Industrial instrumentation Personal navigation devices Hard disk drive (HDD) protection FUNCTIONAL BLOCK DIAGRAM VS VDD I/O ADXL345 POWER MANAGEMENT CONTROL INT1 SENSE ADC AND ELECTRONICS DIGITAL INTERRUPT 3-AXIS FILTER LOGIC INT2 SENSOR SDA/SDI/SDIO 32 LEVEL SERIAL I/O FIFO SDO/ALT ADDRESS SCL/SCLK
1 0 -0 5 2
GND CS
9 7 0 Figure 1.
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