
REV. B
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
Monolithic Accelerometer
Wth Signal Conditioning
ADXL50*
FEATURES
Complete Acceleration Measurement System
on a Single Monolithic IC
Full-Scale Measurement Range:
6
50 g
Self-Test on Digital Command
+5 V Single Supply Operation
Sensitivity Precalibrated to 19 mV/g
Internal Buffer Amplifier for User Adjustable Sensitivity
and Zero-g Level
Frequency Response: DC to 10 kHz
Post Filtering with External Passive Components
High Shock Survival: >2000 g Unpowered
Other Versions Available: ADXL05 (
6
5 g)
FUNCT IONAL BLOCK DIAGRAM
*
Patents pending.
For convenience, the ADX L50 has an internal buffer amplifier
with a full 0.25 V to 4.75 V output range. T his may be used to
set the zero-g level and change the output sensitivity by using
external resistors. External capacitors may be added to the resis-
tor network to provide 1 or 2 poles of filtering. No external
active components are required to interface directly to most
analog-to-digital converters (ADCs) or microcontrollers.
T he ADX L50 uses a capacitive measurement method. T he ana-
log output voltage is directly proportional to acceleration, and is
fully scaled, referenced and temperature compensated, resulting
in high accuracy and linearity over a wide temperature range.
Internal circuitry implements a forced-balance control loop that
improves accuracy by compensating for any mechanical sensor
variations.
T he ADX L50 is powered from a standard +5 V supply and is
robust for use in harsh industrial and automotive environments
and will survive shocks of more than 2000 g unpowered.
T he ADX L50 is available in a hermetic 10-pin T O-100 metal
can, specified over the 0
°
C to +70
°
C commercial, and –40
°
C to
+85
°
C industrial temperature ranges. Contact factory for avail-
ability of devices specified for operation over the –40
°
C to
+105
°
C automotive temperature range.
GE NE RAL DE SCRIPT ION
T he ADX L50 is a complete acceleration measurement system on
a single monolithic IC. T hree external capacitors and a +5 volt
power supply are all that is required to measure accelerations up
to
±
50 g. Device sensitivity is factory trimmed to 19 mV/g,
resulting in a full-scale output swing of
±
0.95 volts for a
±
50 g
applied acceleration. Its zero g output level is +1.8 volts.
A T T L compatible self-test function can electrostatically deflect
the sensor beam at any time to verify device functionality.
V
REF
OUTPUT
V
OUT
DEMODULATOR
REFERENCE
SENSOR
+1.8V
BUFFER
AMP
PREAMP
OSCILLATOR
ADXL50
C2
OSCILLATOR
DECOUPLING
CAPACITOR
SELF TEST
(ST)
C3
+5V
DEMODULATOR
CAPACITOR
C1
C1
COM
R1
V
PR
V
IN–
R3
R2
+3.4V
4
7
5
1
2
3
8
10
9
6
Analog Devices, Inc., 1996
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703