Analog Devices ADXL202E a Datasheet

Low-Cost 2

g

Dual-Axis Accelerometer

a

FEATURES
2-Axis Acceleration Sensor on a Single IC Chip
5 mm  5 mm  2 mm Ultrasmall Chip Scale Package

g

Resolution at 60 Hz

2m
Low-Power < 0.6 mA
Direct Interface to Low-Cost Microcontrollers via

Duty Cycle Output
BW Adjustment with a Single Capacitor
3 V to 5.25 V Single Supply Operation

g

Shock Survival

1000

APPLICATIONS
2-Axis Tilt Sensing with Faster Response than

Electrolytic, Mercury, or Thermal Sensors
Computer Peripherals
Information Appliances
Alarms and Motion Detectors
Disk Drives
Vehicle Security

with Duty Cycle Output

ADXL202E*

FUNCTIONAL BLOCK DIAGRAM

3V TO 5.25V

V

DD

X SENSOR

DEMOD

C

DC

OSCILLATOR

DEMOD

Y SENSOR

COM

C

X

R

FILT

32k

ADXL202E

R

FILT

32k

X

Y

SELF-TEST

FILT

ANALOG

TO

DUTY

CYCLE

(ADC)

T2

FILT

C

R

Y

T2

T1

A(g) = (T1/T2 – 0.5)/12.5%
0g = 50% DUTY CYCLE
T2 = R

SET

SET

X

OUT

Y

OUT

/125M

C
O
U

P

N
T
E
R

GENERAL DESCRIPTION

The ADXL202E is a low-cost, low-power, complete 2-axis acceler­ometer with a digital output, all on a single monolithic IC. It is an
improved version of the ADXL202AQC/JQC. The ADXL202E
will measure accelerations with a full-scale range of ⫾2 g. The
ADXL202E can measure both dynamic acceleration (e.g., vibra­tion) and static acceleration (e.g., gravity).

The outputs are analog voltage or digital signals whose duty cycles
(ratio of pulsewidth to period) are proportional to acceleration.
The duty cycle outputs can be directly measured by a micro­processor counter, without an A/D converter or glue logic. The
duty cycle period is adjustable from 0.5 ms to 10 ms via a single
resistor (R

SET

).

The typical noise floor is 200 ␮g√Hz, allowing signals below
2mg (at 60 Hz bandwidth) to be resolved.

The bandwidth of the accelerometer is set with capacitors C
C

at the X

Y

FILT

and Y

pins. An analog output can be recon-

FILT

and

X

structed by filtering the duty cycle output.

The ADXL202E is available in 5 mm ⫻ 5 mm ⫻ 2 mm 8-lead
hermetic LCC package.

*Patents Pending

REV. A

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: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 2000

ADXL202E–SPECIFICATIONS

(TA = T

MIN

to T

, TA = 25C for J Grade only, VDD = 5 V, R

MAX

Acceleration = 0 g, unless otherwise noted.)

= 125 k,

SET

Parameter Conditions Graph Min Typ Max Min Typ Max Unit

TPC1 ADXL202JE ADXL202AE

SENSOR INPUT Each Axis

Measurement Range
Nonlinearity Best Fit Straight Line 0.2 0.2 % of FS
Alignment Error
Alignment Error X Sensor to Y Sensor 0.01 0.01 Degrees
Cross-Axis Sensitivity

2

3

4

X ±1 ±1 Degrees

X ±2 ±2%

±2 ±2 g

SENSITIVITY Each Axis

Duty Cycle per g T1/T2, VDD = 5 V X 10.5 12.5 14.5 10 12.5 15 %/g

Duty Cycle per g T1/T2, VDD = 3 V X 9.0 11 13.0 8.5 11 13.5 %/g
Sensitivity X
Sensitivity X

FILT

FILT

, Y
, Y

Temperature Drift

FILT

FILT

5

VDD = 5 V X 265 312 360 250 312 375 mV/g
VDD = 3 V X 140 167 195 140 167 200 mV/g
Delta from 25⬚CX ±0.5 ±0.5 %

ZERO g BIAS LEVEL Each Axis

0 g Duty Cycle T1/T2, VDD = 5V X 34 506630 5070 %
0 g Duty Cycle T1/T2, VDD = 3V X 31 506931 5069 %
0 g Voltage X
0 g Voltage X
0 g Duty Cycle vs. Supply X 1.0 4.0 1.0 4.0 %/V
0 g Offset vs. Temperature

FILT

FILT

, Y
, Y

FILT

FILT

VDD = 5 V X 2.1 2.5 2.9 2.0 2.5 3.0 V
VDD = 3 V X 1.2 1.5 1.8 1.2 1.5 1.8 V

5

Delta from 25⬚C X 2.0 2.0 mg/⬚C

NOISE PERFORMANCE

Noise Density @ 25⬚C X 200 200 1000 µg√Hz rms

FREQUENCY RESPONSE

3 dB Bandwidth At Pins X

FILT

, Y

FILT

6 6 kHz

Sensor Resonant Frequency 10 10 kHz

FILTER

R

Tolerance 32 kΩ Nominal ±15 ±15 %

FILT

Minimum Capacitance At Pins X

FILT

, Y

FILT

1000 1000 pF

SELF-TEST

Duty Cycle Change Self-Test “0” to “1” 10 10 %

DUTY CYCLE OUTPUT STAGE

F

SET

Output High Voltage I = 25 µAV

R

= 125 kΩ 0.7 1.3 0.7 1.3 kHz

SET

– 200 mV VS– 200 mV V

S

Output Low Voltage I = 25 µA 200 200 mV
T2 Drift vs. Temperature 50 50 ppm/⬚C
Rise/Fall Time 200 200 ns

POWER SUPPLY

Operating Voltage Range 3 5.25 3.0 5.25 V
Quiescent Supply Current 0.6 1.0 0.6 1.0 mA
Turn-On Time C

in µF 160 ⫻ C

FILT

+ 0.3 160 ⫻ C

FILT

+ 0.3 ms

FILT

TEMPERATURE RANGE

Specified Performance AE –40 +85 ⬚C
Operating Range 0 70 –40 +85 ⬚C

NOTES

1

Typical Performance Characteristics.

2

Guaranteed by measurement of initial offset and sensitivity.

3

Alignment error is specified as the angle between the true and indicated axis of sensitivity (see TPC 15).

4

Cross-axis sensitivity is the algebraic sum of the alignment and the inherent sensitivity errors.

5

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

Specifications subject to change without notice.

–2–

REV. A

ADXL202E

ABSOLUTE MAXIMUM RATINGS*

Acceleration (Any Axis, Unpowered for 0.5 ms) . . . . . . 1000 g

Acceleration (Any Axis, Powered for 0.5 ms) . . . . . . . . . . 500 g

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6.0 V

+V

S

Output Short Circuit Duration, (Any Pin 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 per ma-

nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicate in the opera tional
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

Drops onto hard surfaces can cause shocks of greater than 1000 g
and exceed the absolute maximum rating of the device. Care
should be exercised in handling to avoid damage.

Package Characteristics

Package
Weight 

JA



JC

Device

8-Lead LCC 120°C/W tbd°C/W <1.0 grams

PIN CONFIGURATION

V

DD

8

X

FILT

Y

FILT

OUT

BOTTOM VIEW

7

6

1

ST

2

T2

35

COMX

4

Y

OUT

PIN FUNCTION DESCRIPTIONS

Pin
No. Mnemonic Description

1 ST Self-Test
2 T2 Connect R

SET

3 COM Common
4Y
5X
6Y
7X
8V

OUT

OUT

FILT

FILT

DD

Y-Channel Duty Cycle Output
X-Channel Duty Cycle Output
Y-Channel Filter Pin
X-Channel Filter Pin
3 V to 5.25 V

to Set T2 Period

ORDERING GUIDE

No. Specified Temperature Package Package

Model of Axes Voltage Range Description Option

ADXL202JE 2 3 V to 5 V 0 to 70⬚C 8-Lead LCC E-8
ADXL202AE 2 3 V to 5 V –40⬚C to +85⬚C 8-Lead LCC E-8

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

WARNING!

the ADXL202E 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.

ESD SENSITIVE DEVICE

REV. A

–3–

ADXL202E

–Typical Performance Characteristics*

VDD = 3 V VDD = 5 V

16

14

12

10

8

6

PERCENT OF PARTS

4

2

0

1.32 1.36 1.41 1.45 1.49 1.53 1.58 1.62 1.66

1.28

VOLTS

TPC 1. X-Axis Zero g Bias Distribution at X

16

14

12

10

8

6

PERCENT OF PARTS

4

2

, VDD = 3 V

FILT

18

16

14

12

10

8

6

PERCENT OF PARTS

4

2

0

2.14 2.23 2.31 2.40 2.48 2.57 2.65 2.74 2.82

2.05
VOLTS

TPC 4. X-Axis Zero g Bias Distribution at X

25

20

15

10

PERCENT OF PARTS

5

, VDD = 5 V

FILT

0

1.31 1.36 1.42 1.48 1.59 1.651.53

1.25
VOLTS

TPC 2. Y-Axis Zero g Bias Distribution at Y

25

20

15

10

PERCENT OF PARTS

5

0

0.148 0.155 0.162 0.169 0.176 0.182 0.189

0.142

V/g

TPC 3. X-Axis Sensitivity Distribution at X

*Data taken from 4500 parts over 3 lots minimum.

, VDD = 3 V

FILT

, VDD = 3 V

FILT

0

2.14 2.23 2.31 2.40 2.48 2.57 2.65 2.74 2.82

2.05
VOLTS

TPC 5. Y-Axis Zero g Bias Distribution at Y

25

20

15

10

PERCENT OF PARTS

5

0

0.26

0.28 0.29 0.30 0.32 0.33 0.34
V/g

TPC 6. X-Axis Sensitivity Distribution at X

, VDD = 5 V

FILT

, VDD = 5 V

FILT

–4–

REV. A