FUNCTIONAL BLOCK DIAGRAMS

SELF-TEST

2

25k

5k

ADXL150

GAIN

AMP

OFFSET

NULL

COM

0.1 F

BUFFER

AMP

DEMODULATOR

SENSOR

TP

(DO NOT CONNECT)

9

CLOCK

SELF-TEST

5k

25k

ADXL250

GAIN

AMP

Y OFFSET

NULL

COM

0.1 F

BUFFER

AMP

DEMODULATOR

TP

(DO NOT CONNECT)

25k

5k

GAIN

AMP

BUFFER

AMP

DEMODULATOR

X OFFSET

NULL

SENSOR

2

CLOCK

SENSOR

a

5

g to

50

g, Low Noise, Low Power,

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

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

50

g or

25

g Full Scale

Low Noise: 1 m

g/

√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