ADXL335 [ADI]
Small, Low Power, 3-Axis ±3 g Accelerometer; 小尺寸，低功耗， 3轴±3 g加速度
| 型号： | ADXL335 |
| 厂家： | 
ADI |
| 描述： | Small, Low Power, 3-Axis ±3 g Accelerometer |
| 文件： | 总11页 (文件大小：130K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Small, Low Power, 3-Axis 3 g
Accelerometer
Preliminary Technical Data
ADXL335
FEATURES
GENERAL DESCRIPTION
3-axis sensing
The ADXL335 is a small, thin, low power, complete 3-axis
accelerometer with signal conditioned voltage outputs. The
product measures acceleration with a minimum full-scale range
of 3 g. It can measure the static acceleration of gravity in tilt-
sensing applications, as well as dynamic acceleration resulting
from motion, shock, or vibration.
Small, low-profile package
4 mm × 4 mm × 1.45 mm LFCSP
Low power - 350 μA (typical)
Single-supply operation
1.8 V to 3.6 V
10,000 g shock survival
The user selects the bandwidth of the accelerometer using the
CX, CY, and CZ capacitors at the XOUT, YOUT, and ZOUT pins.
Bandwidths can be selected to suit the application, with a
range of 0.5 Hz to 1600 Hz for X and Y axes, and a range of
0.5 Hz to 550 Hz for the Z axis.
Excellent temperature stability
BW adjustment with a single capacitor per axis
RoHS/WEEE lead-free compliant
APPLICATIONS
Cost-sensitive, low power, motion- and tilt-sensing
applications
The ADXL335 is available in a small, low profile, 4 mm × 4 mm
× 1.45 mm, 16-lead, plastic lead frame chip scale package
(LFCSP_LQ).
Mobile devices
Gaming systems
Disk drive protection
Image stabilization
Sports and health devices
+3V
FUNCTIONAL BLOCK DIAGRAM
Vs
ADXL335
~32kΩ
~32kΩ
~32kΩ
XOUT
CX
Output
Amp
3-Axis
Sensor
AC
Amp
YOUT
CY
Output
Amp
CDC
Demod
ZOUT
CZ
Output
Amp
COM
ST
Figure 1.
Rev. PrA
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 registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2008 Analog Devices, Inc. All rights reserved.
ADXL335
Preliminary Technical Data
TABLE OF CONTENTS
Features .............................................................................................. 1
Performance...................................................................................6
Applications........................................................................................7
Power Supply Decoupling ............................................................7
Setting the Bandwidth Using CX, CY, and CZ .............................7
Self Test...........................................................................................7
Applications....................................................................................... 1
General Description......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 4
ESD Caution.................................................................................. 4
Pin Configuration and Function Descriptions............................. 5
Theory of Operation ........................................................................ 6
Mechanical Sensor........................................................................ 6
Design Trade-Offs for Selecting Filter Characteristics: The
Noise/BW Trade-Off.....................................................................7
Use with Operating Voltages Other than 3 V................................7
Axes of Acceleration Sensitivity ..................................................8
Outline Dimensions..........................................................................9
Ordering Guide .............................................................................9
REVISION HISTORY
Rev. PrA | Page 2 of 11
Preliminary Technical Data
SPECIFICATIONS
ADXL335
TA = 25°C, VS = 3 V, CX = CY = CZ = 0.1 μF, acceleration = 0 g, unless otherwise noted. All minimum and maximum specifications are
guaranteed. Typical specifications are not guaranteed.
Table 1.
Parameter
Conditions
Min
Typ
Max
Unit
SENSOR INPUT
Each axis
Measurement Range
±3
±3.ꢀ
±±.3
±1
±±.1
±1
g
Nonlinearity
% of full scale
%
Package Alignment Error
Interaxis Alignment Error
Cross Axis Sensitivity1
SENSITIVITY (RATIOMETRIC)2
Sensitivity at XOUT, YOUT, ZOUT
Sensitivity Change Due to Temperature3
ZERO g BIAS LEVEL (RATIOMETRIC)
± g Voltage at XOUT, YOUT
± g Voltage at ZOUT
± g Offset vs. Temperature
NOISE PERFORMANCE
Noise Density XOUT, YOUT
Noise Density ZOUT
Degrees
Degrees
%
Each axis
VS = 3 V
VS = 3 V
27±
3±±
±±.±1
33±
mV/g
%/°C
VS = 3 V
VS = 3 V
1.35
1.2
1.5
1.5
±1
1.ꢀ5
1.8
V
V
mg/°C
15±
3±±
μg/√Hz rms
μg/√Hz rms
FREQUENCY RESPONSE4
5
Bandwidth XOUT, YOUT
No external filter
No external filter
1ꢀ±±
55±
Hz
5
Bandwidth ZOUT
Hz
RFILT Tolerance
Sensor Resonant Frequency
SELF TESTꢀ
32 ± 15%
5.5
kΩ
kHz
Logic Input Low
Logic Input High
+±.ꢀ
+2.4
+ꢀ±
−3±±
+3±±
+55±
V
V
ST Actuation Current
Output Change at XOUT
Output Change at YOUT
Output Change at ZOUT
OUTPUT AMPLIFIER
Output Swing Low
Output Swing High
POWER SUPPLY
ꢁA
mV
mV
mV
Self test ± to 1
Self test ± to 1
Self test ± to 1
No load
No load
±.1
2.8
V
V
Operating Voltage Range
Supply Current
Turn-On Time7
1.8
3.ꢀ
V
ꢁA
ms
VS = 3 V
35±
1
No external filter
TEMPERATURE
Operating Temperature Range
−4±
+85
°C
1 Defined as coupling between any two axes.
2 Sensitivity is essentially ratiometric to VS.
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 filter capacitors (CX, CY, CZ).
5 Bandwidth with external capacitors = 1/(2 × π × 32 kΩ × C). For CX, CY = ±.±±3 μF, bandwidth = 1.ꢀ kHz. For CZ = ±.±1 μF, bandwidth = 5±± Hz. For CX, CY, CZ = 1± μF,
bandwidth = ±.5 Hz.
ꢀ Self-test response changes cubically with VS.
7 Turn-on time is dependent on CX, CY, CZ and is approximately 1ꢀ± × CX or CY or CZ + 1 ms, where CX, CY, CZ are in μF.
Rev. PrA | Page 3 of 11
ADXL335
Preliminary Technical Data
ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter
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.
Rating
Acceleration (Any Axis, Unpowered)
Acceleration (Any Axis, Powered)
VS
All Other Pins
Output Short-Circuit Duration
(Any Pin to Common)
1±,±±± g
1±,±±± g
−±.3 V to +3.ꢀ V
(COM − ±.3 V) to (VS + ±.3 V)
Indefinite
Temperature Range (Powered)
Temperature Range (Storage)
−55°C to +125°C
−ꢀ5°C to +15±°C
CRITICAL ZONE
tP
T
TO T
L
P
T
P
RAMP-UP
T
L
tL
T
SMAX
T
SMIN
tS
RAMP-DOWN
PREHEAT
t
25°C TO PEAK
TIME
Figure 2. Recommended Soldering Profile
Table 3. Recommended Soldering Profile
Profile Feature
Sn63/Pb37
Pb-Free
Average Ramp Rate (TL to TP)
Preheat
3°C/s max
3°C/s max
Minimum Temperature (TSMIN
Maximum Temperature (TSMAX
Time (TSMIN to TSMAX), tS
)
1±±°C
15±°C
ꢀ± s to 12± s
15±°C
2±±°C
ꢀ± s to 18± s
)
TSMAX to TL
Ramp-Up Rate
3°C/s max
3°C/s max
Time Maintained Above Liquidous (TL)
Liquidous Temperature (TL)
Time (tL)
Peak Temperature (TP)
Time within 5°C of Actual Peak Temperature (tP)
Ramp-Down Rate
183°C
ꢀ± s to 15± s
24±°C + ±°C/−5°C
1± s to 3± s
ꢀ°C/s max
217°C
ꢀ± s to 15± s
2ꢀ±°C + ±°C/−5°C
2± s to 4± s
ꢀ°C/s max
Time 25°C to Peak Temperature
ꢀ minutes max
8 minutes max
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4±±± 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.
Rev. PrA | Page 4 of 11
Preliminary Technical Data
ADXL335
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
0.50
MAX
4
0.65
0.325
16
15
14
13
+Y
8
0.35
NC
ST
NC
NC
1
2
3
4
ADXL335
TOP VIEW
(Not to Scale)
12
11
10
9
XOUT
NC
MAX
0.65
4
1.95
+Z
YOUT
NC
0.325
CENTER PAD IS NOT
+X
INTERNALLY CONNECTED
BUT SHOULD BE SOLDERED
FOR MECHANICAL INTEGRITY
5
6
7
1.95
DIMENSIONS SHOWN IN MILLIMETERS
Figure 4. Recommended PCB Layout
Figure 3. Pin Configuration
Table 4. Pin Function Descriptions
Pin No.
Mnemonic
Description
1
2
3
4
NC
ST
NC
NC
No Connect (or optionally ground)
Self Test
No Connect1
No Connect1
5
ꢀ
7
COM
NC
NC
Common
No Connect1
No Connect1
8
9
ZOUT
NC
YOUT
NC
XOUT
NC
NC
Z Channel Output
No Connect (or optionally ground)
Y Channel Output
No Connect1
X Channel Output
No Connect1
No Connect1
1±
11
12
13
14
15
1ꢀ
VS
NC
Supply Voltage (1.8 V to 3.ꢀ V)
No Connect1
1NC pins are not internally connected and can be tied to Vs or Common unless otherwise noted.
Rev. PrA | Page 5 of 11
ADXL335
Preliminary Technical Data
THEORY OF OPERATION
The ADXL335 is a complete 3-axis acceleration measurement
system. The ADXL335 has a measurement range of 3 g
minimum. It contains a polysilicon surface micromachined
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
accelerometer can measure the static acceleration of gravity in
tilt sensing applications as well as dynamic acceleration
resulting from motion, shock, or vibration.
MECHANICAL SENSOR
The ADXL335 uses a single structure for sensing the X, Y, and
Z axes. As a result, the three axes sense directions are highly
orthogonal with little cross axis sensitivity. Mechanical mis-
alignment of the sensor die to the package is the chief source
of cross axis sensitivity. Mechanical misalignment can, of
course, be calibrated out at the system level.
PERFORMANCE
Rather than using additional temperature compensation
circuitry, innovative design techniques ensure high
performance is built-in to the ADXL335. As a result, there is
neither quantization error nor nonmonotonic behavior, and
temperature hysteresis is very low (typically less than 3 mg over
the −25°C to +70°C temperature range).
The sensor is a polysilicon surface micromachined structure
built on top of a 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 meas-
ured 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 moving mass and unbalances the differential
capacitor resulting in a sensor output whose amplitude is
proportional to acceleration. Phase-sensitive demodulation
techniques are then used to determine the magnitude and
direction of the acceleration.
The demodulator output is amplified and brought off-chip
through a 32 kΩ resistor. The user then sets the signal band-
width of the device by adding a capacitor. This filtering improves
measurement resolution and helps prevent aliasing.
Rev. PrA | Page ꢀ of 11
Preliminary Technical Data
ADXL335
APPLICATIONS
Never expose the ST pin to voltages greater than VS + 0.3 V. If
this cannot be guaranteed due to the system design (for
instance, if there are multiple supply voltages), then a low VF
clamping diode between ST and VS is recommended.
POWER SUPPLY DECOUPLING
For most applications, a single 0.1 μF capacitor, CDC, placed
close to the ADXL335 supply pins adequately decouples the
accelerometer from noise on the power supply. However, in
applications where noise is present at the 50 kHz internal clock
frequency (or any harmonic thereof), additional care in power
supply bypassing is required as this noise can cause errors in
acceleration measurement. If additional decoupling is needed,
a 100 Ω (or smaller) resistor or ferrite bead can be inserted in
the supply line. Additionally, a larger bulk bypass capacitor
(1 μF or greater) can be added in parallel to CDC. Ensure that
the connection from the ADXL335 ground to the power supply
ground is low impedance because noise transmitted through
ground has a similar effect as noise transmitted through VS.
DESIGN TRADE-OFFS FOR SELECTING FILTER
CHARACTERISTICS: THE NOISE/BW TRADE-OFF
The selected accelerometer bandwidth ultimately determines
the measurement resolution (smallest detectable acceleration).
Filtering can be used to lower the noise floor to improve the
resolution of the accelerometer. Resolution is dependent on the
analog filter bandwidth at XOUT, YOUT, and ZOUT
.
The output of the ADXL335 has a typical bandwidth of greater
than 500 Hz. 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.
SETTING THE BANDWIDTH USING CX, CY, AND CZ
The ADXL335 has provisions for band limiting the XOUT, YOUT
and ZOUT pins. Capacitors must be added at these pins to
implement low-pass filtering for antialiasing and noise
reduction. The equation for the 3 dB bandwidth is
,
The ADXL335 noise has the characteristics of white Gaussian
noise, which contributes equally at all frequencies and is
described in terms of ꢀg/√Hz (the noise is proportional to the
square root of the accelerometer bandwidth). The user should
limit bandwidth to the lowest frequency needed by the applica-
tion to maximize the resolution and dynamic range of the
accelerometer.
F
−3 dB = 1/(2π(32 kΩ) × C(X, Y, Z)
or more simply
–3 dB = 5 ꢀF/C(X, Y, Z)
The tolerance of the internal resistor (RFILT) typically varies as
)
F
much as 15% of its nominal value (32 kΩ), and the bandwidth
varies accordingly. A minimum capacitance of 0.0047 ꢀF for CX,
CY, and CZ is recommended in all cases.
With the single-pole, roll-off characteristic, the typical noise of
the ADXL335 is determined by
rms Noise = Noise Density × ( BW ×1.6)
Table 5. Filter Capacitor Selection, CX, CY, and CZ
Bandwidth (Hz)
Capacitor (μF)
Often, the peak value of the noise is desired. Peak-to-peak noise
can only be estimated by statistical methods. Table 6 is useful
for estimating the probabilities of exceeding various peak
values, given the rms value.
1
1±
5±
1±±
2±±
5±±
4.7
±.47
±.1±
±.±5
±.±27
±.±1
Table 6. Estimation of Peak-to-Peak Noise
% of Time that Noise Exceeds
Nominal Peak-to-Peak Value
Peak-to-Peak Value
2 × rms
32
SELF TEST
4 × rms
4.ꢀ
The ST pin controls the self test feature. When this pin is set to
VS, an electrostatic force is exerted on the accelerometer beam.
The resulting movement of the beam allows the user to test if
the accelerometer is functional. The typical change in output is
−500 mg (corresponding to −150 mV) in the X-axis, 500 mg (or
150 mV) on the Y-axis, and −200 mg (or −60 mV) on the Z-axis.
This ST pin may be left open circuit or connected to common
(COM) in normal use.
ꢀ × rms
8 × rms
±.27
±.±±ꢀ
USE WITH OPERATING VOLTAGES OTHER THAN 3 V
The ADXL335 is tested and specified at VS = 3 V; however, it
can be powered with VS as low as 1.8 V or as high as 3.6 V. Note
that some performance parameters change as the supply voltage
is varied.
Rev. PrA | Page 7 of 11
ADXL335
Preliminary Technical Data
At VS = 2 V, the self test response is approximately −60 mV for
the X-axis, +60 mV for the Y-axis, and −25 mV for the Z-axis.
The ADXL335 output is ratiometric, therefore, the output
sensitivity (or scale factor) varies proportionally to the
supply voltage. At VS = 3.6 V, the output sensitivity is
typically 360 mV/g. At VS = 2 V, the output sensitivity is
typically 195 mV/g.
The supply current decreases as the supply voltage decreases.
Typical current consumption at VS = 3.6 V is 375 μA, and
typical current consumption at VS = 2 V is 200 μA.
The zero g bias output is also ratiometric, so the zero g output is
nominally equal to VS/2 at all supply voltages.
AXES OF ACCELERATION SENSITIVITY
A
Z
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 VS = 3.6 V, the
X- and Y-axis noise density is typically 120 μg/√Hz, while at
VS = 2 V, the X- and Y-axis noise density is typically 270 ꢀg/√Hz.
A
Y
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, the self test response in volts
is roughly proportional to the cube of the supply voltage. For
example, at VS = 3.6 V, the self test response for the ADXL335 is
approximately −275 mV for the X-axis, +275 mV for the Y-axis,
and −100 mV for the Z-axis.
TO
P
A
X
Figure 5. Axes of Acceleration Sensitivity, Corresponding Output Voltage
Increases When Accelerated Along the Sensitive Axis
X
Y
Z
= –1g
= 0g
= 0g
OUT
OUT
OUT
TOP
GRAVITY
X
Y
Z
= 0g
= –1g
= 0g
X
Y
Z
= 0g
= 1g
= 0g
OUT
OUT
OUT
OUT
TOP
TOP
OUT
OUT
TOP
X
Y
Z
= 1g
= 0g
= 0g
OUT
OUT
OUT
T
O
P
X
Y
Z
= 0g
= 0g
= 1g
X
Y
Z
= 0g
= 0g
= –1g
OUT
OUT
OUT
OUT
OUT
OUT
Figure 6. Output Response vs. Orientation to Gravity
Rev. PrA | Page 8 of 11
Preliminary Technical Data
OUTLINE DIMENSIONS
ADXL335
0.20 MIN
13
PIN 1
INDICATOR
0.20 MIN
0.65 BSC
16
PIN 1
INDICATOR
1
4
12
9
4.15
4.00 SQ
3.85
2.43
1.75 SQ
1.08
TOP
VIEW
BOTTOM
VIEW
8
5
0.55
0.50
0.45
1.95 BSC
0.05 MAX
0.02 NOM
1.50
1.45
1.40
0.35
0.30
0.25
COPLANARITY
0.05
SEATING
PLANE
*
STACKED DIE WITH GLASS SEAL.
Figure 7. 16-Lead Lead Frame Chip Scale Package [LFCSP_LQ]
4 mm × 4 mm Body, 1.45mm Thick Quad
(CP-16-5a*)
Dimensions shown in millimeters
ORDERING GUIDE
Model
Measurement Range Specified Voltage
Temperature Range Package Description Package Option
ADXL335BCPZ1
±3 g
±3 g
±3 g
3 V
3 V
3 V
−4±°C to +85°C
−4±°C to +85°C
−4±°C to +85°C
1ꢀ-Lead LFCSP_LQ
1ꢀ-Lead LFCSP_LQ
1ꢀ-Lead LFCSP_LQ
Evaluation Board
CP-1ꢀ-5a
CP-1ꢀ-5a
CP-1ꢀ-5a
ADXL335BCPZ–RL1
ADXL335BCPZ–RL71
EVAL-ADXL335Z1
1 Z = Pb-free part.
Rev. PrA | Page 9 of 11
ADXL335
NOTES
Preliminary Technical Data
Rev. PrA | Page 1± of 11
Preliminary Technical Data
NOTES
ADXL335
©2008 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
PR07808-0-9/08(PrA)
Rev. PrA | Page 11 of 11
相关型号：
©2020 ICPDF网 联系我们和版权申明