ANALOG DEVICES ADXL322 Service Manual

Small and Thin ±2 g Accelerometer

FEATURES

Small and thin

4 mm × 4 mm × 1.45 mm LFCSP package
2 mg resolution at 60 Hz
Wide supply voltage range: 2.4 V to 6 V
Low power: 340 μA at VS = 2.4 V (typ)
Good zero g bias stability
Good sensitivity accuracy
X-axis and Y-axis aligned to within 0.1° (typ)
BW adjustment with a single capacitor
Single-supply operation
10,000 g shock survival
Pb Free: Compatible with Sn/Pb and Pb-free solder processes

APPLICATIONS

Cost-sensitive motion- and tilt-sensing applications

Smart hand-held devices

Mobile phones

Sports and health-related devices

PC security and PC peripherals

ADXL322

GENERAL DESCRIPTION

The ADXL322 is a small, thin, low power, complete, dual-axis
accelerometer with signal conditioned voltage outputs, which
are all on a single monolithic IC. The product measures accel­eration with a full-scale range of ±2 g (typical). It can also
measure both dynamic acceleration (vibration) and static
acceleration (gravity).

The ADXL322’s typical noise floor is 220 μg/√Hz, which allows
signals below 2 mg to be resolved in tilt-sensing applications
using narrow bandwidths (<60 Hz).

The user selects the bandwidth of the accelerometer using
capacitors C

and CY at the X

X

of 0.5 Hz to 2.5 kHz can be selected to suit the application.

The ADXL322 is available in a 4 mm × 4 mm × 1.45 mm,
16-lead, plastic LFCSP.

OUT

and Y

pins. Bandwidths

OUT

FUNCTIONAL BLOCK DIAGRAM

+3V

V

S

ADXL322

C

DC

SENSOR

COM ST

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.

AC

AMP

DEMOD

Figure 1.

OUTPUT

AMP

R

FILT

32kΩ

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
Fax: [phone]

OUTPUT

AMP

R

FILT

32kΩ

Y

OUT

C

Y

X

OUT

C

X

05589-001

www.analog.com

© 2007 Analog Devices, Inc. All rights reserved.

ADXL322

TABLE OF CONTENTS

Specifications..................................................................................... 3

Absolute Maximum Ratings............................................................ 4

ESD Caution.................................................................................. 4

Pin Configuration and Function Descriptions............................. 5

Typical Performance Characteristics (V

Theory of Operation ...................................................................... 11

Performance ................................................................................ 11

Applications..................................................................................... 12

Power Supply Decoupling .........................................................12

= 3.0 V)....................... 7

S

REVISION HISTORY

6/05—Revision 0: Initial Version

Setting the Bandwidth Using CX and C

Self-Test ....................................................................................... 12

Design Trade-Offs for Selecting Filter Characteristics: The

Noise/BW Trade-Off.................................................................. 12

Use with Operating Voltages Other than 3 V............................. 13

Use as a Dual-Axis Tilt Sensor ................................................. 13

Outline Dimensions .......................................................................14

Ordering Guide .......................................................................... 14

................................. 12

Y

Rev. 0 | Page 2 of 16

ADXL322

SPECIFICATIONS

TA = 25°C, VS = 3 V, CX = CY = 0.1 μF, Acceleration = 0 g, unless otherwise noted1.

Table 1.

Parameter Conditions Min Typ Max Unit

SENSOR INPUT Each axis

Measurement Range ±2

Nonlinearity % of full scale ±0.2 %

Package Alignment Error ±1 Degrees

Alignment Error X sensor to Y sensor ±0.1 Degrees

Cross-Axis Sensitivity ±2 %

, Y

OUT

2

Each axis
VS = 3 V 378 420 462 mV/g

3

VS = 3 V 0.01 %/°C

SENSITIVITY (RATIOMETRIC)

Sensitivity at X

OUT

Sensitivity Change due to Temperature
ZERO g BIAS LEVEL (RATIOMETRIC) Each axis

0 g Voltage at X

OUT

, Y

OUT

VS = 3 V 1.3 1.5 1.7 V
Initial 0 g Bias Deviation from Ideal ±50 mg
0 g Offset Vs. Temperature <±0.5 mg/°C

NOISE PERFORMANCE

Noise Density at 25°C 220 μg/√Hz rms

FREQUENCY RESPONSE

CX, CY Range
R

Tolerance 32 ± 15% kΩ

FILT

5

4

0.002 10 μF

Sensor Resonant Frequency 5.5 kHz

SELF-TESTT

6

Logic Input Low 0.6 V
Logic Input High 2.4 V
ST Input Resistance to Ground 50 kΩ
Output Change at X

OUT

, Y

OUT

Self-test 0 to 1 125 mV

OUTPUT AMPLIFIER

Output Swing Low No load 0.2 V
Output Swing High No load 2.7 V

POWER SUPPLY

Operating Voltage Range 2.4 6 V
Quiescent Supply Current 0.45 mA
Turn-On Time

7

20 ms

TEMPERATURE

Operating Temperature Range −20 70 °C

1

All minimum and maximum specifications are guaranteed. Typical specifications are not guaranteed.

2

Sensitivity is essentially ratiometric to VS. For VS = 2.7 V to 3.3 V, sensitivity is 138 mV/V/g to 142 mV/V/g typical.

3

Defined as the output change from ambient-to-maximum temperature or ambient-to-minimum temperature.

4

Actual frequency response controlled by user-supplied external capacitor (CX, CY).

5

Bandwidth = 1/(2 × π × 32 kΩ × C). For CX, CY = 0.002 μF, bandwidth = 2500 Hz. For CX, CY = 10 μF, bandwidth = 0.5 Hz. Minimum/maximum values are not tested.

6

Self-test response changes cubically with VS.

7

Larger values of CX, CY increase turn-on time. Turn-on time is approximately 160 × CX or CY + 4 ms, where CX, CY are in μF.

g

Rev. 0 | Page 3 of 16

ADXL322

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

Acceleration (Any Axis, Unpowered) 10,000 g
Acceleration (Any Axis, Powered) 10,000 g
V

S

All Other Pins

Output Short-Circuit Duration
(Any Pin to Common)

Operating Temperature Range −55°C to +125°C
Storage Temperature −65°C to +150°C

−0.3 V to +7.0 V
(COM − 0.3 V) to

+ 0.3 V)

(V

S

Indefinite

ESD 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 this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.

Rev. 0 | Page 4 of 16

ADXL322

T

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

NC VSVSNC

NC X

ST

COM

NC NC

NC = NO CONNEC

ADXL322

TOP VIEW

(Not to Scale)

COM COM COM NC

NC

Y

OUT

OUT

05589-022

Figure 2. Pin Configuration

Table 3. Pin Function Descriptions

Pin No. Mnemonic Description

1 NC Do Not Connect
2 ST Self-Test
3 COM Common
4 NC Do Not Connect
5 COM Common
6 COM Common
7 COM Common
8 NC Do Not Connect
9 NC Do Not Connect
10 Y

OUT

Y-Channel Output
11 NC Do Not Connect
12 X

OUT

X-Channel Output
13 NC Do Not Connect
14 V
15 V

S

S

2.4 V to 6 V

2.4 V to 6 V

16 NC Do Not Connect

4.000

1.950

0.325

0.650

0.325

4.000

05589-023

0.350
MAX

0.600
MAX

1.950

0.650

Figure 3. 4 mm × 4 mm 16- pad LFCSP Recommended Pad Layout

Rev. 0 | Page 5 of 16