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Low Cost ±1.2
g
Dual
Axis Accelerometer
ADXL213
FEATURES
Dual axis accelerometer on a single IC chip
5 mm × 5 mm × 2 mm LCC package
1 m
g
resolution at 60 Hz
Low power: 700 μA at V
S
= 5 V (typical)
High zero
g
bias stability
High sensitivity accuracy
Pulse width modulated digital outputs
X and Y axes aligned to within 0.1° (typical)
BW adjustment with a single capacitor
Single-supply operation
3500
g
shock survival
APPLICATIONS
Automotive tilt alarms
Data projectors
Navigation
Platform stabilization/leveling
Alarms and motion detectors
High accuracy, 2-axis tilt sensing
Rev.
0
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.
Tel: 781.329.4700Fax: 781.326.8703
www.analog.com GENERAL DESCRIPTION
The ADXL213 is a low cost, low power, complete dual axis
accelerometer with signal conditioned, duty cycle modulated
outputs, all on a single monolithic IC. The ADXL213 measures
acceleration with a full-scale range of ±1.2
g
(typical). The
ADXL213 can measure both dynamic acceleration (e.g.,
vibration) and static acceleration (e.g., gravity).
The outputs are digital signals whose duty cycles (ratio of pulse
width to period) are proportional to acceleration (30%/
g
). The
duty cycle outputs can be directly measured by a microcontrol-
ler without an A/D converter or glue logic.
Innovative design techniques are used to ensure high zero
g
bias
stability (typically better than 0.25 m
g
/°C), as well as tight sensi-
tivity stability (typically better than 50 ppm/°C).
The typical noise floor is 160 μg/√Hz, allowing signals below
1 m
g
(0.06° of inclination) to be resolved in tilt sensing applica-
tions using narrow bandwidths (<60 Hz).
The user selects the bandwidth of the accelerometer using
capacitors C
X
and C
Y
at the X
FILT
and Y
FILT
pins. Bandwidths of
0.5 Hz to 250 Hz may be selected to suit the application.
The ADXL213 is available in a 5 mm × 5 mm × 2 mm, 8-pad
hermetic LCC package.
FUNCTIONAL BLOCK DIAGRAM
0
ADXL213
SENSOR
32k
32k
+V
S
OUTPUT
AMP
OUTPUT
AMP
DCM
COM
ST
X
FILT
C
X
Y
FILT
+V
S
C
DC
DEMOD
C
Y
T2
R
SET
Y
OUT
X
OUT
AC
AMP
A(
g
) = (T1/T2 – 0.5)/30%
0
g
= 50% DUTY CYCLE
T2(s) = R
SET
/125M
T2
T1
Figure 1.