ADXL312 Datasheet, PDF (1/32 Pages) Analog Devices – 3-Axis, ±1.5 g/±3 g/±6 g/±12 g Digital Accelerometer

3-Axis, ±1.5 g/±3 g/±6 g/±12 g
Digital Accelerometer
ADXL312
FEATURES
GENERAL DESCRIPTION
Ultralow power: as low as 57 μA in measurement mode and
0.1 μA in standby mode at VS = 3.3 V (typical)
Power consumption scales automatically with bandwidth
User-selectable resolution
Fixed 10-bit resolution
Full resolution, where resolution increases with g range,
up to 13-bit resolution at ±12 g (maintaining 2.9 mg/LSB
scale factor in all g ranges)
Embedded, patent pending FIFO technology minimizes host
processor load
Built-in motion detection functions for activity/inactivity
monitoring
Supply and I/O voltage range: 2.0 V to 3.6 V
SPI (3- and 4-wire) and I²C digital interfaces
Flexible interrupt modes mappable to either interrupt pin
Measurement ranges selectable via serial command
Bandwidth selectable via serial command
Wide temperature range (−40 to +105°C)
10,000 g shock survival
Pb free/RoHS compliant
Small and thin: 5 mm × 5 mm × 1.45 mm LFCSP package
Qualified for automotive applications
The ADXL312 is a small, thin, low power, 3-axis accelerometer
with high resolution (13-bit) measurement up to ±12 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 ADXL312 is well suited for car alarm or black box applica-
tions. It measures the static acceleration of gravity in tilt-sensing
applications, as well as dynamic acceleration resulting from
motion or shock. Its high resolution (2.9 mg/LSB) enables
resolution of inclination changes of as little as 0.25°. A built-in
FIFO facilitates using oversampling techniques to improve
resolution to as little as 0.05° of inclination.
Several special sensing functions are provided. Activity and
inactivity sensing detects the presence or absence of motion and
whether the acceleration on any axis exceeds a user-set level.
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.
Low power modes enable intelligent motion-based power
management with threshold sensing and active acceleration
measurement at extremely low power dissipation.
APPLICATIONS
Car alarm
Hill start aid (HSA)
Electronic parking brake
Data recorder (black box)
The ADXL312 is supplied in a small, thin 5 mm × 5 mm ×
1.45 mm, 32-lead, LFCSP package.
FUNCTIONAL BLOCK DIAGRAM
V_S V_{DD I/O}
ADXL312
POWER
MANAGEMENT
3-AXIS
SENSOR
SENSE
ELECTRONICS
ADC
DIGITAL
FILTER
CONTROL
AND
INTERRUPT
LOGIC
INT1
INT2
32 LEVEL
FIFO
SERIAL I/O
GND
CS
Figure 1. ADXL312 Simplified Block Diagram
SDA/SDI/SDIO
SDO/ALT
ADDRESS
SCL/SCLK
Rev. 0
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