FUNCTIONAL BLOCK DIAGRAMS
SELF-TEST
+V
S
2
25kV
5kV
ADXL150
GAIN
AMP
OFFSET
NULL
COM
0.1mF
BUFFER
AMP
DEMODULATORSENSOR
+V
S
TP
(DO NOT CONNECT)
V
OUT
9
CLOCK
SELF-TEST
5kV
25kV
ADXL250
GAIN
AMP
Y OFFSET
NULL
COM
0.1mF
BUFFER
AMP
DEMODULATOR
+V
S
TP
(DO NOT CONNECT)
25kV
5kV
GAIN
AMP
BUFFER
AMP
DEMODULATOR
V
OUT
Y
X OFFSET
NULL
SENSOR
+V
S
2CLOCK
SENSOR
V
OUT
X
a
65 g to 650 g, Low Noise, Low Power,
Single/Dual Axis iMEMS

Accelerometers
ADXL150/ADXL250
GENERAL DESCRIPTION
The ADXL150 and ADXL250 are third generation ±50 g sur-
face micromachined accelerometers. These improved replace-
ments for the ADXL50 offer lower noise, wider dynamic range,
reduced power consumption and improved zero g bias drift.
The ADXL150 is a single axis product; the ADXL250 is a fully
integrated dual axis accelerometer with signal conditioning on a
single monolithic IC, the first of its kind available on the com-
mercial market. The two sensitive axes of the ADXL250 are
orthogonal (90°) to each other. Both devices have their sensitive
axes in the same plane as the silicon chip.
The ADXL150/ADXL250 offer lower noise and improved
signal-to-noise ratio over the ADXL50. Typical S/N is 80 dB,
allowing resolution of signals as low as 10 mg, yet still providing
a ±50 g full-scale range. Device scale factor can be increased
from 38 mV/g to 76 mV/g by connecting a jumper between
V
OUT
and the offset null pin. Zero g drift has been reduced to
0.4 g over the industrial temperature range, a 10× improvement
over the ADXL50. Power consumption is a modest 1.8 mA
per axis. The scale factor and zero g output level are both
FEATURES
Complete Acceleration Measurement System
on a Single Monolithic IC
80 dB Dynamic Range
Pin Programmable 650 g or 625 g Full Scale
Low Noise: 1 mg/√Hz Typical
Low Power: <2 mA per Axis
Supply Voltages as Low as 4 V
2-Pole Filter On-Chip
Ratiometric Operation
Complete Mechanical & Electrical Self-Test
Dual & Single Axis Versions Available
Surface Mount Package
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
ratiometric to the power supply, eliminating the need for a volt-
age reference when driving ratiometric A/D converters such as
those found in most microprocessors. A power supply bypass
capacitor is the only external component needed for normal
operation.
The ADXL150/ADXL250 are available in a hermetic 14-lead
surface mount cerpac package specified over the 0°C to +70°C
commercial and –40°C to +85°C industrial temperature ranges.
Contact factory for availability of devices specified over automo-
tive and military temperature ranges.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 World Wide Web Site: http://www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 1998
iMEMS is a registered trademark of Analog Devices, Inc.