Datasheet ADXL103 Datasheet (ANALOG DEVICES)

Precision ±1.7 g, ±5 g, ±18 g Single-/

Data Sheet

FEATURES

High performance, single-/dual-axis accelerometer on

a single IC chip 5 mm × 5 mm × 2 mm LCC package 1 mg resolution at 60 Hz Low power: 700 μA at V High zero g bias stability High sensitivity accuracy

−40°C to +125°C temperature range X and Y axes aligned to within 0.1° (typical) Bandwidth adjustment with a single capacitor Single-supply operation 3500 g shock survival RoHS compliant Compatible with Sn/Pb- and Pb-free solder processes Qualified for automotive applications

APPLICATIONS

Vehicle dynamic controls Electronic chassis controls Platform stabilization/leveling Navigation Alarms and motion detectors High accuracy, 2-axis tilt sensing Vibration monitoring and compensation Abuse event detection

= 5 V (typical)

S

Dual-Axis iMEMS

®

Accelerometer

ADXL103/ADXL203

GENERAL DESCRIPTION

The ADXL103/ADXL203 are high precision, low power, complete single- and dual-axis accelerometers with signal conditioned voltage outputs, all on a single, monolithic IC. The ADXL103/

ADXL203 measure acceleration with a full-scale range of ±1.7 g,

±5 g, or ±18 g. The ADXL103/ADXL203 can measure both dynamic acceleration (for example, vibration) and static acceleration (for example, gravity).

The typical noise floor is 110 μg/√Hz, allowing signals below 1 mg (0.06° of inclination) to be resolved in tilt sensing applications using narrow bandwidths (<60 Hz).

The user selects the bandwidth of the accelerometer using Capacitor C Bandwidths of 0.5 Hz to 2.5 kHz can be selected to suit the application.

The ADXL103 and ADXL203 are available in a 5 mm × 5 mm × 2 mm, 8-terminal ceramic LCC package.

and Capacitor CY at the X

X

OUT

and Y

OUT

pins.

FUNCTIONAL BLOCK DIAGRAMS

+5V

V

S

ADXL103

C

DC

SENSOR

COM ST X

Rev. D

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her 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

R

FILT

32kΩ

OUTPUT

AMP

C

OUT

X

+5V

V

S

ADXL203

C

DC

SENSOR

COM ST Y

Figure 1.

AC

AMP

DEMOD

R

FILT

32kΩ

OUTPUT

AMP

C

OUT

Y

OUTPUT

R

FILT

32kΩ

AMP

X

OUT

C

X

03757-001

ADXL103/ADXL203 Data Sheet

REVISION HISTORY

9/11—Rev. C to Rev. D

Added AD22293, AD22035, and AD22037............... Throughout

Changes to Application Section and General Description

Section................................................................................................ 1

Changes to Table 1............................................................................ 3

Deleted Figure 13 and Figure 14: Renumbered Sequentially ..... 7

Deleted Figure 17 and Figure 22..................................................... 8

Added Figure 19 to Figure 24; Renumbered Sequentially .......... 9

Added Figure 25 to Figure 34........................................................10

Added All Models Section, Figure 35 to Figure 38.................... 12

Changes to Figure 39...................................................................... 13

Changes to Ordering Guide.......................................................... 16

Changes to Automotive Products Section................................... 16

5/10—Rev. B to Rev. C

Changes to Figure 24 Caption....................................................... 12

Added Automotive Products Section .......................................... 12

4/10—Rev. A to Rev. B

Changes to Features Section............................................................1

Updated Outline Dimensions....................................................... 12

Changes to Ordering Guide.......................................................... 12

2/06—Rev. 0 to Rev. A

Changes to Features..........................................................................1

Changes to Table 1.............................................................................3

Changes to Figure 2...........................................................................4

Changes to Figure 3 and Figure 4....................................................5

Changes to the Performance Section..............................................9

4/04—Revision 0: Initial Version

Rev. D | Page 2 of 16

Data Sheet ADXL103/ADXL203

SPECIFICATIONS

TA = −40°C to +125°C, VS = 5 V, CX = CY = 0.1 μF, acceleration = 0 g, unless otherwise noted. All minimum and maximum specifications are guaranteed. All typical specifications are not guaranteed.

Table 1.

ADXL103/ADXL203 AD22293 AD22035/AD22037 Parameter Test Conditions Min Typ Max Min Typ Max Min Typ Max Unit

SENSOR Each axis

Measurement Range1 ±1.7 ±5 ±6 ±18 Nonlinearity % of full scale ±0.2 ±1.25 ±0.2 ±1.25 ±0.2 ±1.25 % Package Alignment Error ±1 ±1 ±1 Degrees Alignment Error (ADXL203) X to Y sensor ±0.1 ±0.1 ±0.1 Degrees Cross-Axis Sensitivity ±1.5 ±3 ±1.5 ±3 ±1.5 ±3 %

SENSITIVITY (RATIOMETRIC)2 Each axis

Sensitivity at X Sensitivity Change Due to

Temperature

, Y

V

OUT

3

= 5 V 960 1000 1040 293 312 331 94 100 106 mV/g

S

VS = 5 V ±0.3 ±0.3 ±0.3

ZERO g BIAS LEVEL (RATIOMETRIC) Each axis

0 g Voltage at X Initial 0 g Output Deviation

, Y

V

OUT

= 5 V 2.4 2.5 2.6 2.4 2.5 2.6 2.4 2.5 2.6 V

S

V

= 5 V, 25°C ±25 ±50 ±125 mg

S

From Ideal

0 g Offset vs. Temperature ±0.1 ±0.8 ±0.3 ±1.8 ±1 mg/°C

NOISE

Output Noise <4 kHz, VS = 5 V 1 3 1 3 2 mV rms Noise Density 110 200 130

FREQUENCY RESPONSE4

CX, CY Range5 0.002 10 0.002 10 0.002 10 μF R

Tolerance 24 32 40 24 32 40 24 32 40 kΩ

FILT

Sensor Resonant Frequency 5.5 5.5 5.5 kHz

SELF TEST6

Logic Input Low 1 1 1 V Logic Input High 4 4 4 V ST Input Resistance to GND 30 50 30 50 30 50 kΩ Output Change at X

, Y

ST 0 to ST 1 450 750 1100 125 250 375 60 80 100 mV

OUT

OUTPUT AMPLIFIER

Output Swing Low No load 0.05 0.2 0.05 0.2 0.05 0.2 V Output Swing High No load 4.5 4.8 4.5 4.8 4.5 4.8 V

POWER SUPPLY (VDD)

Operating Voltage Range 3 6 3 6 3 6 V Quiescent Supply Current 0.7 1.1 0.7 1.1 0.7 1.1 mA Turn-On Time7 20 20 20 ms

1

Guaranteed by measurement of initial offset and sensitivity.

2

Sensitivity is essentially ratiometric to VS. For VS = 4.75 V to 5.25 V, sensitivity is 186 mV/V/g to 215 mV/V/g.

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

%

μg/√Hz rms

Rev. D | Page 3 of 16

ADXL103/ADXL203 Data Sheet

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

Acceleration (Any Axis, Unpowered) 3500 g Acceleration (Any Axis, Powered) 3500 g Drop Test (Concrete Surface) 1.2 m VS −0.3 V to +7.0 V All Other Pins

Output Short-Circuit Duration

(COM − 0.3 V) to (V

+ 0.3 V)

S

Indefinite

(Any Pin to Common) Temperature Range (Powered) −55°C to +125°C Temperature Range (Storage) −65°C to +150°C

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.

T

P

T

L

T

SMAX

RAMP-UP

Table 3. Package Characteristics

Package Type θJA θ

Device Weight

JC

8-Terminal Ceramic LCC 120°C/W 20°C/W <1.0 gram

ESD CAUTION

CRITICAL ZONE

TO T

t

P

T

L

P

t

L

T

SMIN

TEMPERAT URE

t

S

PREHEAT

t

25°C TO PE AK

Figure 2. Recommended Soldering Profile

RAMP-DOWN

TIME

03757-102

Table 4. Solder Profile Parameters

Test Condition Profile Feature Sn63/Pb37 Pb-Free

Average Ramp Rate (TL to TP) 3°C/second maximum 3°C/second maximum Preheat

Minimum Temperature (T

Maximum Temperature (T

Time (T T

to TL

SMAX

SMIN

to T

) (tS) 60 seconds to 120 seconds 60 seconds to 150 seconds

SMAX

) 100°C 150°C

SMIN

) 150°C 200°C

SMAX

Ramp-Up Rate 3°C/second 3°C/second Time Maintained above Liquidous (TL)

Liquidous Temperature (TL) 183°C 217°C

Time (tL) 60 seconds to 150 seconds 60 seconds to 150 seconds Peak Temperature (TP) 240°C + 0°C/−5°C 260°C + 0°C/−5°C Time Within 5°C of Actual Peak Temperature (tP) 10 seconds to 30 seconds 20 seconds to 40 seconds Ramp-Down Rate 6°C/second maximum 6°C/second maximum Time 25°C to Peak Temperature 6 minutes maximum 8 minutes maximum

Rev. D | Page 4 of 16

Data Sheet ADXL103/ADXL203

.

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

ADXL103

TOP VIEW

(Not to Scale)

V

S

8

1

ST

NC

2

COM

3

NOTES

1. NC = NO CONNECT . DO NOT CONNECT TO THIS PI N

Figure 3. ADXL103 Pin Configuration

7

X

+X

4

NC

OUT

6

NC

5

NC

03757-002

NOTES

1. NC = NO CONNECT . DO NOT CONNECT TO THIS PIN

Figure 4. ADXL203 Pin Configuration

ST

NC

COM

ADXL203

TOP VIEW

(Not to Scale)

V

S

8

1

+Y

2

+X

3

4

NC

7

X

OUT

6

Y

OUT

5

NC

03757-003

Table 5. ADXL103 Pin Function Descriptions

Pin No. Mnemonic Description

1 ST Self Test 2 NC Do Not Connect 3 COM Common 4 NC Do Not Connect 5 NC Do Not Connect 6 NC Do Not Connect 7 X

X Channel Output

OUT

8 VS 3 V to 6 V

Table 6. ADXL203 Pin Function Descriptions

Pin No. Mnemonic Description

1 ST Self Test 2 NC Do Not Connect 3 COM Common 4 NC Do Not Connect 5 NC Do Not Connect 6 Y 7 X

Y Channel Output

OUT

X Channel Output

OUT

8 VS 3 V to 6 V

Rev. D | Page 5 of 16

ADXL103/ADXL203 Data Sheet

A

TYPICAL PERFORMANCE CHARACTERISTICS

ADXL103 AND ADXL203

VS = 5 V for all graphs, unless otherwise noted.

25

30

20

15

10

5

PERCENT OF POPULATION (%)

0

–0.10

–0.08

–0.06

–0.04

0

–0.02

ZERO g BIAS (V)

0.02

0.04

Figure 5. X-Axis Zero g Bias Deviation from Ideal at 25°C

30

25

20

15

10

PERCENT OF POPULATION (%)

5

25

20

15

10

PERCENT OF POPULATION (%)

5

03757-010

0.06

0.08

0.10

0

–0.10

–0.08

–0.06

–0.04

0

–0.02

ZERO g BIAS (V)

0.02

0.04

0.06

03757-013

0.08

0.10

Figure 8. Y-Axis Zero g Bias Deviation from Ideal at 25°C

25

20

TION (%)

15

10

PERCENT OF POPUL

5

0

–0.80

–0.70

–0.60

–0.40

–0.30

–0.50

TEMPERATURE COEFFICIENT (mg/°C)

0

0.10

–0.20

–0.10

0.20

Figure 6. X-Axis Zero g Bias Temperature Coefficient

40

35

30

25

20

15

10

PERCENT OF POPULATION (%)

5

0

0.94

0.95

0.96

0.98

0.99

1.00

1.01

0.97

SENSITIVITY (V/g)

1.02

Figure 7. X-Axis Sensitivity at 25°C

03757-011

0.30

0.40

0.50

0.60

0.70

0.80

0

–0.80

–0.70

–0.60

–0.40

–0.30

–0.50

TEMPERATURE COEFFICIENT (mg/°C)

0

0.10

0.20

0.30

0.40

–0.20

–0.10

0.50

03757-014

0.60

0.70

0.80

Figure 9. Y-Axis Zero g Bias Temperature Coefficient

40

35

30

25

20

15

10

PERCENT OF POPULATION (%)

5

03757-012

1.03

1.04

1.05

1.06

0

0.94

0.95

0.96

0.98

0.99

1.00

1.01

1.02

1.03

0.97

SENSITIVITY (V/g)

1.04

03757-015

1.05

1.06

Figure 10. Y-Axis Sensitivity at 25°C

Rev. D | Page 6 of 16

Data Sheet ADXL103/ADXL203

2.60

2.58

2.56

2.54

2.52

2.50

2.48

VOLTAGE (1V/g)

2.46

2.44

2.42

2.40

–50

–40

–30

0

–20

–10

1020305040

TEMPERATURE (°C)

607080

Figure 11. Zero g Bias vs. Temperature; Parts Soldered to PCB

50

45

40

35

30

25

20

15

10

PERCENT OF POPULATI ON (%)

5

0

X AXIS NOISE DENSITY (mg/√Hz)

Figure 12. X-Axis Noise Density at 25°C

1.03

1.02

1.01

)

g

1.00

0.99

SENSITIVITY (V/

0.98

90

100

03757-004

110

120

130

0.97

0

–20

–10

1020305040

TEMPERATURE (°C)

–40

–30

–50

607080

90

100

03757-016

110

120

130

Figure 13. Sensitivity vs. Temperature; Parts Soldered to PCB

50

45

40

35

30

25

20

15

10

PERCENT OF POPULATI ON (%)

5

03757-007

15014013012011010090807060

0

Y AXIS NOISE DENSITY (mg/√Hz)

03757-008

15014013012011010090807060

Figure 14. Y-Axis Noise Density at 25°C

Rev. D | Page 7 of 16

ADXL103/ADXL203 Data Sheet

45

40

35

30

25

20

15

10

PERCENT OF POPULATION (%)

5

0

0.40

0.45

0.50

0.65

0.60

0.70

0.55

SELF-TEST OUTPUT (V)

0.75

0.80

0.85

0.90

03757-017

0.95

1.00

Figure 15. X-Axis Self-Test Response at 25°C

0.90

0.85

0.80

)

0.75

g

0.70

0.65

VOLTAGE (1V/

0.60

0.55

0.50

0

–50

–40

–30

–20

–10

1020305040

TEMPERATURE (°C)

607080

90

100

03757-103

110

120

130

Figure 16. Self-Test Response vs. Temperature

45

40

35

30

25

20

15

10

PERCENT OF POPULATION (%)

5

0

0.40

0.45

0.50

0.65

0.60

0.70

0.55

SELF-TEST OUTPUT (V)

0.75

0.80

0.85

0.90

03757-019

0.95

1.00

Figure 17. Y-Axis Self-Test Response at 25°C

100

90

80

70

60

50

40

30

20

PERCENT OF POPULATION (%)

10

0

200

3V

300

400

5V

500

600

CURRENT (µA)

03757-018

700

800

900

1000

Figure 18. Supply Current at 25°C

Rev. D | Page 8 of 16

Data Sheet ADXL103/ADXL203

A

AD22293

60

70

50

40

TION (%)

30

20

PERCENT OF POPUL

10

0

2.43

2.44

2.45

2.46

2.47

2.48

2.49

2.50

2.51

2.52

2.53

2.54

2.55

2.56

2.57

ZERO g BIAS (V)

03757-117

Figure 19. X-Axis Zero g Bias at 25°C

25

20

TION (%)

15

10

60

50

TION (%)

40

30

20

PERCENT OF POPUL

10

0

2.43

2.44

2.45

2.46

2.47

2.48

2.49

2.50

2.51

2.52

2.53

2.54

2.55

2.56

ZERO g BIAS (V)

2.57

03757-119

Figure 22. Y-Axis Zero g Bias at 25°C

25

20

TION (%)

15

10

PERCENT OF POPUL

5

0

–1.2

–1.0

–0.8

–0.6

TEMPERATURE COEFFICI ENT (mg/°C)

0

0.2

–0.4

–0.2

0.4

Figure 20. X-Axis Zero g Bias Temperature Coefficient

90

80

70

60

TION (%)

50

40

30

20

PERCENT OF POPUL

10

0

0.287

0.297

0.307

0.317

0.327

0.337

SENSITIVITY (V/g)

0.347

Figure 21. X-Axis Sensitivity at 25°C

0.357

0.6

0.8

1.0

1.2

03757-118

0.367

0.377

0.387

03757-021

PERCENT OF POPUL

5

0

–1.2

–1.0

–0.8

–0.6

TEMPERATURE COEFFICIENT (mg/°C)

0

0.2

–0.4

–0.2

0.4

Figure 23. Y-Axis Zero g Bias Temperature Coefficient

80

70

60

TION (%)

50

40

30

20

PERCENT OF POPUL

10

0

0.287

0.297

0.307

0.317

0.327

0.337

SENSITIVITY (V/g)

0.347

Figure 24. Y-Axis Sensitivity at 25°C

0.6

0.8

1.0

1.2

03757-020

0.357

0.367

0.377

0.387

03757-022

Rev. D | Page 9 of 16

ADXL103/ADXL203 Data Sheet

A

AD22035 AND AD22037

60

50

TION

40

30

20

PERCENT OF POPUL

10

0

–50

–40

–30

–20

0

–10

ZERO g BIAS (mV)

10

20

30

Figure 25. X-Axis Zero g Bias Deviation from Ideal at 25°C

35

30

25

TION

20

15

10

PERCENT OF POPUL

5

50

TION

40

30

20

PERCENT OF POPUL

10

0

40

50

03757-105

–50

–40

–30

–20

0

–10

ZERO g BIAS (mV)

10

20

30

40

50

03757-108

Figure 28. Y-Axis Zero g Bias Deviation from Ideal at 25°C

35

30

25

TION

20

15

10

PERCENT OF POPUL

5

0

–2.5

–3.0

–1.5

–2.0

TEMPERATURE COEFFICIENT (mg/°C)

0

1.0

0.5

–1.0

–0.5

1.5

Figure 26. X-Axis Zero g Bias Temperature Coefficient

25

20

TION

15

10

PERCENT OF POPUL

5

0

97

98

99

SENSITIVITY (mV/g)

100

101

Figure 27. X-Axis Sensitivity at 25°C

0

2.5

2.0

3.5

3.0

03757-106

–2.5

–3.0

–1.5

–2.0

TEMPERATURE COEFFICIENT (mg/°C)

0

1.0

0.5

1.5

2.5

2.0

–1.0

–0.5

3.0

03757-009

Figure 29. Y-Axis Zero g Bias Temperature Coefficient

25

20

TION

15

10

PERCENT OF POPUL

5

0

97

102

103

98

03757-107

99

100

SENSITIVITY (mV/g)

101

102

103

03757-110

Figure 30. Y-Axis Sensitivity at 25°C

Rev. D | Page 10 of 16

Data Sheet ADXL103/ADXL203

A

40

35

30

TION

25

20

15

10

PERCENT OF POPUL

5

0

0.060

0.065

0.070

0.075

0.080

SELF-TEST OUTPUT (V)

0.085

Figure 31. X-Axis Self Test Response at 25°C

101.0

100.5

100.0

99.5

99.0

SENSITIVITY (mV)

98.5

98.0

97.5 –50 –25 0 25 50 75 100 1 25

TEMPERATURE (°C)

Figure 32. Sensitivity vs. Temperature; Parts Soldered to PCB

0.090

0.095

0.100

03757-111

03757-112

TION

PERCENT OF POPUL

TION

PERCENT OF POPUL

45

40

35

30

25

20

15

10

5

0

0.060

0.065

0.070

0.075

SELF-TEST OUTPUT (V)

Figure 33. Y-Axis Self Test Response at 25°C

90

80

70

60

50

40

30

20

10

0

25°C 105°C

680

700

720

740

760

780

CURRENT (µA)

800

Figure 34. Supply Current vs. Temperature

0.080

820

840

0.085

0.090

0.095

0.100

03757-114

900

920

860

880

940

960

03757-113

Rev. D | Page 11 of 16

ADXL103/ADXL203 Data Sheet

%

m

%

ALL MODELS

40

35

)

30

25

20

15

10

PERCENT OF POPULATION (

5

0

–4.0

–5.0

–3.0

–2.0

PERCENT SENSITIVITY (%)

–1.0

0

1.0

2.0

3.0

4.0

5.0

09781-023

Figure 35. Z vs. X Cross-Axis Sensitivity

0.9

0.8

0.7

A)

0.6

CURRENT (

0.5

0.4

VS=5V

VS=3V

35

)

30

25

20

15

10

PERCENT OF POPULATION (

5

0

–4.0

–5.0

–3.0

–2.0

PERCENT SENSITIVITY (%)

–1.0

0

1.0

2.0

3.0

4.0

5.0

09781-026

Figure 37. Z vs. Y Cross-Axis Sensitivity

VOLTAGE (V)

0.3

TEMPERATURE (°C)

Figure 36. Supply Current vs. Temperature

150100500–50

09781-024

Figure 38. Turn-On Time; C

TIME

, CY = 0.1 μF, Time Scale = 2 ms/DIV

X

09781-027

Rev. D | Page 12 of 16

Data Sheet ADXL103/ADXL203

THEORY OF OPERATION

The ADXL103/ADXL203 are complete acceleration measurement systems on a single, monolithic IC. The ADXL103 is a single- axis accelerometer, and the ADXL203 is a dual-axis accelerometer. Both parts contain a polysilicon surface-micro-machined sensor and signal conditioning circuitry to implement an open-loop acceleration measurement architecture. The output signals are analog voltages that are proportional to acceleration. The

ADXL103/ADXL203 are capable of measuring both positive

and negative accelerations from ±1.7 g to at least ±18 g. The accelerometer can measure static acceleration forces, such as gravity, allowing it to be used as a tilt sensor.

The sensor is a surface-micromachined polysilicon structure built on top of the silicon wafer. Polysilicon springs suspend the structure over the surface of the wafer and provide a resistance against acceleration forces. Deflection of the structure is measured using a differential capacitor that consists of independent fixed plates and plates attached to the moving mass. The fixed plates are driven by 180° out-of-phase square waves. Acceleration deflects the beam and unbalances the differential capacitor, resulting in an output square wave whose amplitude is proportional to acceleration. Phase-sensitive demodulation techniques are then used to rectify the signal and determine the direction of the acceleration.

PIN 8

X

OUT

Y

OUT

= –1g

= 0g

The output of the demodulator is amplified and brought off-chip through a 32 kΩ resistor. At this point, the user can set the signal bandwidth of the device by adding a capacitor. This filtering improves measurement resolution and helps prevent aliasing.

PERFORMANCE

Rather than using additional temperature compensation circuitry, innovative design techniques have been used to ensure that high performance is built in. As a result, there is essentially no quantization error or nonmonotonic behavior, and temperature hysteresis is very low (typically less than 10 mg over the −40°C to +125°C temperature range).

Figure 11 shows the 0 g output performance of eight parts (x and y axes) over a −40°C to +125°C temperature range.

Figure 13 demonstrates the typical sensitivity shift over temperature for V V

= 5 V but is still very good over the specified range; it is

S

typically better than ±1% over temperature at V

= 5 V. Sensitivity stability is optimized for

S

= 3 V.

S

PIN 8

= 0g

X

OUT

= +1g

Y

OUT

TOP VIEW

(Not to Scale)

PIN 8

X

= +1g

OUT

= 0g

Y

OUT

PIN 8

= 0g

X

OUT

= –1g

Y

OUT

X

OUT

Y

OUT

EARTH’S SURFACE

= 0g = 0g

03757-028

Figure 39. Output Response vs. Orientation

Rev. D | Page 13 of 16

ADXL103/ADXL203 Data Sheet

APPLICATIONS INFORMATION

POWER SUPPLY DECOUPLING

For most applications, a single 0.1 μF capacitor, CDC, adequately decouples the accelerometer from noise on the power supply. However, in some cases, particularly where noise is present at the 140 kHz internal clock frequency (or any harmonic thereof), noise on the supply can cause interference on the ADXL103/

ADXL203 output. If additional decoupling is needed, a 100 Ω

(or smaller) resistor or ferrite beads can be inserted in the supply line of the ADXL103/ADXL203. Additionally, a larger bulk bypass capacitor (in the 1 μF to 22 μF range) can be added in parallel to C

DC

.

SETTING THE BANDWIDTH USING CX AND CY

The ADXL103/ADXL203 has provisions for band limiting the X

OUT

and Y

pins. Capacitors must be added at these pins to

OUT

implement low-pass filtering for antialiasing and noise reduction. The equation for the 3 dB bandwidth is

= 1/(2π(32 kΩ) × C

f

–3 dB

(X, Y)

)

or more simply,

f

= 5 μF/C

–3 dB

The tolerance of the internal resistor (R

(X, Y)

) can vary typically as

FILT

much as ±25% of its nominal value (32 kΩ); thus, the bandwidth varies accordingly. A minimum capacitance of 2000 pF for C C

is required in all cases.

Y

Table 7. Filter Capacitor Selection, C

and CY

X

and

X

Bandwidth (Hz) Capacitor (μF)

1 4.7 10 0.47 50 0.10 100 0.05 200 0.027 500 0.01

SELF TEST

The ST pin controls the self test feature. When this pin is set to VS, an electrostatic force is exerted on the beam of the accelerometer. The resulting movement of the beam allows the user to test if the accelerometer is functional. The typical change in output is 750 mg (corresponding to 750 mV). This pin can be left opencircuit or connected to common in normal use.

Never expose the ST pin to voltages greater than V the system design is such that this condition cannot be guaranteed (that is, multiple supply voltages are present), a low V diode between ST and V

is recommended.

S

+ 0.3 V. If

S

clamping

F

DESIGN TRADE-OFFS FOR SELECTING FILTER CHARACTERISTICS: THE NOISE/BANDWIDTH TRADE-OFF

The accelerometer bandwidth selected ultimately determines the measurement resolution (smallest detectable acceleration). Filtering can be used to lower the noise floor, improving the resolution of the accelerometer. Resolution is dependent on the analog filter bandwidth at X

The output of the ADXL103/ADXL203 has a typical bandwidth of 2.5 kHz. The user must filter the signal at this point to limit aliasing errors. The analog bandwidth must be no more than half the analog-to-digital sampling frequency to minimize aliasing. The analog bandwidth can be further decreased to reduce noise and improve resolution.

The ADXL103/ADXL203 noise has the characteristics of white Gaussian noise, which contributes equally at all frequencies and is described in terms of μg/√Hz (that is, the noise is proportional to the square root of the accelerometer bandwidth). Limit bandwidth to the lowest frequency needed by the application to maximize the resolution and dynamic range of the accelerometer.

With the single-pole roll-off characteristic, the typical noise of the ADXL103/ADXL203 is determined by

rmsNoise = (110 μg/√Hz) × (

At 100 Hz, the noise is

rmsNoise = (110 μg/√Hz) × (

Often, the peak value of the noise is desired. Peak-to-peak noise can only be estimated by statistical methods. Table 8 is useful for estimating the probabilities of exceeding various peak values, given the rms value.

Table 8. Estimation of Peak-to-Peak Noise

% of Time That Noise Exceeds

Peak-to-Peak Value

Nominal Peak-to-Peak Value

2 × rms 32 4 × rms 4.6 6 × rms 0.27 8 × rms 0.006

Peak-to-peak noise values give the best estimate of the uncertainty in a single measurement; peak-to-peak noise is estimated by 6 × rms. Table 9 gives the typical noise output of the ADXL103/

ADXL203 for various C

and CY values.

X

Table 9. Filter Capacitor Selection (C

C

, C

X

Bandwidth (Hz)

Y

(μF)

10 0.47 0.4 2.6 50 0.1 1.0 6 100 0.047 1.4 8.4 500 0.01 3.1 18.7

and Y

OUT

RMS Noise (mg)

.

OUT

)

6.1BW×

) = 1.4 mg

6.1100×

, CY)

X

Peak-to-Peak Noise Estimate (mg)

Rev. D | Page 14 of 16

Data Sheet ADXL103/ADXL203

USING THE ADXL103/ADXL203 WITH OPERATING VOLTAGES OTHER THAN 5 V

The ADXL103/ADXL203 is tested and specified at VS = 5 V; however, it can be powered with V as 6 V. Some performance parameters change as the supply voltage is varied.

The ADXL103/ADXL203 output is ratiometric, so the output sensitivity (or scale factor) varies proportionally to the supply voltage. At V

= 3 V, the output sensitivity is typically 560 mV/g.

S

The zero g bias output is also ratiometric, so the zero g output is nominally equal to V

/2 at all supply voltages.

S

The output noise is not ratiometric but is absolute in volts; therefore, the noise density decreases as the supply voltage increases. This is because the scale factor (mV/g) increases while the noise voltage remains constant. At V noise density is typically 190 μg/√Hz.

Self test response in g is roughly proportional to the square of the supply voltage. However, when ratiometricity of sensitivity is factored in with supply voltage, self test response in volts is roughly proportional to the cube of the supply voltage. So at V

= 3 V, the self test response is approximately equivalent to

S

150 mV or equivalent to 270 mg (typical). The supply current decreases as the supply voltage decreases.

Typical current consumption at V

as low as 3 V or as high

S

= 3 V, the

S

= 3 V is 450 μA.

DD

USING THE ADXL203 AS A DUAL-AXIS TILT SENSOR

One of the most popular applications of the ADXL203 is tilt measurement. An accelerometer uses the force of gravity as an input vector to determine the orientation of an object in space.

An accelerometer is most sensitive to tilt when its sensitive axis is perpendicular to the force of gravity, that is, parallel to the earth’s surface. At this orientation, its sensitivity to changes in tilt is highest. When the accelerometer is oriented on axis to gravity, that is, near its +1 g or –1 g reading, the change in output acceleration per degree of tilt is negligible. When the accelerometer is perpendicular to gravity, its output changes nearly 17.5 mg per degree of tilt. At 45°, its output changes at only 12.2 mg per degree, and resolution declines.

Dual-Axis Tilt Sensor: Converting Acceleration to Tilt

When the accelerometer is oriented so both its x-axis and y-axis are parallel to the earth’s surface, it can be used as a 2-axis tilt sensor with a roll axis and a pitch axis. Once the output signal from the accelerometer has been converted to an acceleration that varies between –1 g and +1 g, the output tilt in degrees is calculated as

PITCH = ASIN(A ROLL = ASIN(A

Be sure to account for overranges. It is possible for the accelerometers to output a signal greater than ±1 g due to vibration, shock, or other accelerations.

X

/1 g)

Y

/1 g)

Rev. D | Page 15 of 16

ADXL103/ADXL203 Data Sheet

OUTLINE DIMENSIONS

0.030

0.025

0.020

7

5

BOTTOM VIEW

DETAILA

0.180

0.177 SQ

0.174

R 0.008

(4 PLCS)

0.203

0.197 SQ

0.193

TOP VIEW

0.020

0.015

0.010

(R 4 PLCS)

0.008

0.006

0.004

0.087

0.078

0.069

0.077

0.070

0.063

0.075 REF

R 0.008

(8 PLCS)

0.054

0.050

0.046

(OPTION 2)

Figure 40. 8-Terminal Ceramic Leadless Chip Carrier [LCC]

(E-8-1)

Dimensions shown in inches

ORDERING GUIDE

Device Generic g-Range

Model

1, 2

Axes

ADXL103CE 1 ADXL103 ±1.7 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADXL103CE–REEL 1 ADXL103 ±1.7 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADXL103WCEZB-REEL 1 ADXL103 ±1.7 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 AD22035Z 1 ADXL103 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 AD22035Z-RL 1 ADXL103 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 AD22035Z-RL7 1 ADXL103 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADW22035Z 1 ADXL103 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADW22035Z-RL 1 ADXL103 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADW22035Z-RL7 1 ADXL103 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADXL203CE 2 ADXL203 ±1.7 5 –40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADXL203CE-REEL 2 ADXL203 ±1.7 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADXL203WCEZB-REEL 2 ADXL203 ±1.7 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADXL203EB Evaluation Board AD22293ZA 2 ADXL203 ±5 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADW22293ZA 2 ADXL203 ±5 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 AD22037Z 2 ADXL203 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 AD22037Z-RL 2 ADXL203 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 AD22037Z-RL7 2 ADXL203 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADW22037Z 2 ADXL203 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADW22037Z-RL 2 ADXL203 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1 ADW22037Z-RL7 2 ADXL203 ±18 5 −40°C to +125°C 8-Terminal Ceramic LCC E-8-1

1

Z = RoHS Compliant Part.

2

W = Qualified for Automotive Applications.

Specified Voltage (V) Temperature Range Package Description

1

3

0.019 SQ

(PLATING OPTION1, SEE DETAILA FOROPTION2)

0.028

0.020 DIA

0.012

0.106

0.100

0.094

05-21-2010-D

Package Option

AUTOMOTIVE PRODUCTS

The ADXL103W, ADW22035, ADXL203W, ADW22293, and ADW22037 models are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models.

Rev. D | Page 16 of 16

Datasheet ADXL103 Datasheet (ANALOG DEVICES)

Specifications and Main Features

Frequently Asked Questions

User Manual

FEATURES

APPLICATIONS

GENERAL DESCRIPTION

FUNCTIONAL BLOCK DIAGRAMS

TABLE OF CONTENTS

REVISION HISTORY

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

ESD CAUTION

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

TYPICAL PERFORMANCE CHARACTERISTICS

ADXL103 AND ADXL203

AD22293

AD22035 AND AD22037

ALL MODELS

THEORY OF OPERATION

PERFORMANCE

APPLICATIONS INFORMATION

POWER SUPPLY DECOUPLING

SETTING THE BANDWIDTH USING CX AND CY

SELF TEST

DESIGN TRADE-OFFS FOR SELECTING FILTER CHARACTERISTICS: THE NOISE/BANDWIDTH TRADE-OFF

USING THE ADXL103/ADXL203 WITH OPERATING VOLTAGES OTHER THAN 5 V

USING THE ADXL203 AS A DUAL-AXIS TILT SENSOR

Dual-Axis Tilt Sensor: Converting Acceleration to Tilt

OUTLINE DIMENSIONS

ORDERING GUIDE

AUTOMOTIVE PRODUCTS