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a ؎5 g to ؎50 g, Low Noise, Low Power,
Single/Dual Axis iMEMS® Accelerometers
ADXL150/ADXL250
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 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
+VS
0.1F
FUNCTIONAL BLOCK DIAGRAMS
TP
(DO NOT CONNECT)
ADXL150
GAIN
AMP
SENSOR
CLOCK
+VS
2
DEMODULATOR
25k
5k
BUFFER
AMP
9
SELF-TEST
COM
OFFSET
NULL
TP
(DO NOT CONNECT)
X OFFSET
NULL
VOUT
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
VOUT 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
+VS
0.1F
ADXL250
GAIN
AMP
SENSOR
25k
DEMODULATOR
5k
SENSOR
CLOCK
GAIN
AMP
5k
DEMODULATOR
25k
BUFFER
AMP
VOUTX
+VS
2
BUFFER
AMP
VOUTY
SELF-TEST
COM
Y OFFSET
NULL
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.
iMEMS is a registered trademark of Analog Devices, Inc.
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.
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

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ADXL150/ADXL250–SPECIFICATIONS (TA = +25؇C for J Grade, TA = –40؇C to +85؇C for A Grade,
VS = +5.00 V, Acceleration = Zero g, unless otherwise noted)
Parameter
Conditions
ADXL150JQC/AQC
Min Typ Max
ADXL250JQC/AQC
Min Typ Max
Units
SENSOR
Guaranteed Full-Scale Range
Nonlinearity
Package Alignment Error1
Sensor-to-Sensor Alignment Error
Transverse Sensitivity2
± 40 ± 50
0.2
±1
±2
± 40 ± 50
0.2
±1
± 0.1
±2
g
% of FS
Degrees
Degrees
%
SENSITIVITY
Sensitivity (Ratiometric)3
Y Channel
X Channel
Sensitivity Drift Due to Temperature Delta from 25°C to TMIN or TMAX
ZERO g BIAS LEVEL
Output Bias Voltage4
Zero g Drift Due to Temperature
Delta from 25°C to TMIN or TMAX
ZERO-g OFFSET ADJUSTMENT
Voltage Gain
Input Impedance
Delta VOUT/Delta VOS PIN
33.0 38.0 43.0
± 0.5
33.0 38.0 43.0
33.0 38.0 43.0
± 0.5
mV/g
mV/g
%
VS/2 – 0.35 VS/2 VS/2 + 0.35 VS/2 – 0.35 VS/2 VS/2 + 0.35 V
0.2 0.3 g
0.45 0.50 0.55
20 30
0.45 0.50 0.55
20 30
V/V
k
NOISE PERFORMANCE
Noise Density5
Clock Noise
1 2.5
5
1 2.5
5
mg/Hz
mV p-p
FREQUENCY RESPONSE
–3 dB Bandwidth
Bandwidth Temperature Drift
Sensor Resonant Frequency
TMIN to TMAX
Q=5
900 1000
50
24
900 1000
50
24
Hz
Hz
kHz
SELF-TEST
Output Change6
Logic “1” Voltage
Logic “0” Voltage
Input Resistance
ST Pin from Logic “0” to “1”
To Common
0.25
VS – 1
30
0.40 0.60
1.0
50
0.25
VS – 1
30
0.40 0.60
1.0
50
V
V
V
k
OUTPUT AMPLIFIER
Output Voltage Swing
Capacitive Load Drive
IOUT = ±100 µA
0.25
1000
VS – 0.25 0.25
1000
VS – 0.25 V
pF
POWER SUPPLY (VS)7
Functional Voltage Range
Quiescent Supply Current
ADXL150
ADXL250 (Total 2 Channels)
4.0
6.0
1.8 3.0
4.0 6.0
3.5 5.0
V
mA
mA
TEMPERATURE RANGE
Operating Range J
Specified Performance A
0
+70 0
+70 °C
–40
+85 –40
+85 °C
NOTES
1Alignment error is specified as the angle between the true axis of sensitivity and the edge of the package.
2Transverse sensitivity is measured with an applied acceleration that is 90 degrees from the indicated axis of sensitivity.
3Ratiometric: VOUT = VS/2 + (Sensitivity × VS/5 V × a) where a = applied acceleration in gs, and VS = supply voltage. See Figure 21. Output scale factor can be
doubled by connecting VOUT to the offset null pin.
4Ratiometric, proportional to VS/2. See Figure 21.
5See Figure 11 and Device Bandwidth vs. Resolution section.
6Self-test output varies with supply voltage.
7When using ADXL250, both Pins 13 and 14 must be connected to the supply for the device to function.
Specifications subject to change without notice.
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ADXL150/ADXL250
ABSOLUTE MAXIMUM RATINGS*
Acceleration (Any Axis, Unpowered for 0.5 ms) . . . . . . 2000 g
Acceleration (Any Axis, Powered for 0.5 ms) . . . . . . . . . 500 g
+VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7.0 V
Output Short Circuit Duration
(VOUT, VREF Terminals to Common) . . . . . . . . . . . Indefinite
Operating Temperature . . . . . . . . . . . . . . . . . –55°C to +125°C
Storage Temperature . . . . . . . . . . . . . . . . . . . –65°C to +150°C
*Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; the functional operation of
the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
Package Characteristics
Package
JA
14-Lead Cerpac 110°C/W
JC
30°C/W
Device Weight
5 Grams
ORDERING GUIDE
Model
ADXL150JQC
ADXL150AQC
ADXL250JQC
ADXL250AQC
Temperature Range
0°C to +70°C
–40°C to +85°C
0°C to +70°C
–40°C to +85°C
Drops onto hard surfaces can cause shocks of greater than 2000 g
and exceed the absolute maximum rating of the device. Care
should be exercised in handling to avoid damage.
1 14
ADXL150
TOP VIEW
(Not to Scale)
AX
78
1 ADXL25014
TOP VIEW
(Not to Scale)
AX
AY 90؇
7
8
POSITIVE A = POSITIVE VOUT
POSITIVE A = POSITIVE VOUT
Figure 1. ADXL150 and ADXL250 Sensitive Axis
Orientation
PIN CONNECTIONS
NC
NC
NC
NC
TP (DO NOT CONNECT)
NC
COMMON
1 14
ADXL150
TOP VIEW
(Not to Scale)
78
VS
NC
NC
NC
VOUT
SELF-TEST
ZERO g ADJ
NC
ZERO g ADJ Y
VOUT Y
NC
TP (DO NOT CONNECT)
NC
COMMON
1 14
ADXL250
TOP VIEW
(Not to Scale)
78
VS
VS
NC
NC
VOUT X
SELF-TEST
ZERO g ADJ X
NC = NO CONNECT
NOTE: WHEN USING ADXL250, BOTH PINS 13 AND 14 NEED
TO BE CONNECTED TO SUPPLY FOR DEVICE TO FUNCTION
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the ADXL150/ADXL250 feature proprietary ESD protection circuitry, permanent
damage may occur on devices subjected to high energy electrostatic discharges. Therefore, pro per
ESD precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
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ADXL150/ADXL250
GLOSSARY OF TERMS
Acceleration: Change in velocity per unit time.
Acceleration Vector: Vector describing the net acceleration
acting upon the ADXL150/ADXL250.
g: A unit of acceleration equal to the average force of gravity
occurring at the earth’s surface. A g is approximately equal to
32.17 feet/s2 or 9.807 meters/s2.
Nonlinearity: The maximum deviation of the ADXL150/
ADXL250 output voltage from a best fit straight line fitted to a
plot of acceleration vs. output voltage, calculated as a % of the
full-scale output voltage (at 50 g).
Resonant Frequency: The natural frequency of vibration of
the ADXL150/ADXL250 sensor’s central plate (or “beam”). At
its resonant frequency of 24 kHz, the ADXL150/ADXL250’s
moving center plate has a slight peak in its frequency response.
Sensitivity: The output voltage change per g unit of accelera-
tion applied, specified at the VOUT pin in mV/g.
Total Alignment Error: Net misalignment of the ADXL150/
ADXL250’s on-chip sensor and the measurement axis of the
application. This error includes errors due to sensor die align-
ment to the package, and any misalignment due to installation
of the sensor package in a circuit board or module.
Transverse Acceleration: Any acceleration applied 90° to the
axis of sensitivity.
Transverse Sensitivity Error: The percent of a transverse
acceleration that appears at VOUT.
Transverse Axis: The axis perpendicular (90°) to the axis of
sensitivity.
Zero g Bias Level: The output voltage of the ADXL150/
ADXL250 when there is no acceleration (or gravity) acting
upon the axis of sensitivity. The output offset is the difference
between the actual zero g bias level and (VS/2).
Polarity of the Acceleration Output
The polarity of the ADXL150/ADXL250 output is shown in
Figure 1. When its sensitive axis is oriented to the earth’s gravity
(and held in place), it will experience an acceleration of +1 g.
This corresponds to a change of approximately +38 mV at the
output pin. Note that the polarity will be reversed if the package
is rotated 180°. The figure shows the ADXL250 oriented so that
its “X” axis measures +1 g. If the package is rotated 90° clock-
wise (Pin 14 up, Pin 1 down), the ADXL250’s “Y” axis will now
measure +1 g.
8 7 8 AY 7
AX
ADXL150
14 1
AX
ADXL250
14 1
Figure 2. Output Polarity
Acceleration Vectors
The ADXL150/ADXL250 is a sensor designed to measure
accelerations that result from an applied force. It responds to
the component of acceleration on its sensitive X axis (ADXL150)
or on both the “X” and “Y” axis (ADXL250).
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ADXL150/ADXL250
Typical Characteristics (@+5 V dc, +25؇C with a 38 mV/g Scale Factor unless otherwise noted)
6
5.0
4.0 0
3.0 –6
2.0
–12
PACKAGE
RESONANCE
1.0 –18
0
–1.0
–2.0
–3.0
–4.0
–5.0
4.0
4.5 5.0 5.5
POWER SUPPLY VOLTAGE
6.0
–24
–30
–36
–42
–48
100
BEAM
RESONANCE
1k
FREQUENCY – Hz
10k
Figure 3. Typical Sensitivity Error from Ideal Ratiometric
Response for a Number of Units
Figure 6. Typical Output Response vs. Frequency of
ADXL150/ADXL250 on a PC Board that Has Been
Conformally Coated
2.5
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
4.0 4.5 5.0 5.5 6.0
SUPPLY VOLTAGE
Figure 4. Offset Error of Zero g Level from Ideal
VS /2 Response as a Percent of Full-Scale for a Number
of Units
30
20
10
0
–10
–20
–30
–40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100
TEMPERATURE – ؇C
Figure 7. Typical Zero g Drift for a Number of Units
2.4
2.2
+105؇C
2
+25؇C
1.8
–40؇C
1.6
1.4
1.2
4
4.5 5 5.5
SUPPLY VOLTAGE – Volts
6
Figure 5. Typical Supply Current vs. Supply Voltage
600g
60g
500g
400g
500g INPUT
50g
40g
300g
200g
OUTPUT RESPONSE
30g
20g
100g
10g
0g 0g
TIME – 0.2ms/Div
Figure 8. Typical 500 g Step Recovery at the Output
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