Dual-Axis ±1.7 g Accelerometer
with SPI Interface
Data Sheet ADIS16003
Rev. B
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FEATURES
Dual-axis accelerometer
SPI digital output interface
Internal temperature sensor
Highly integrated; minimal external components
Bandwidth externally selectable
1 mg resolution at 60 Hz
Externally controlled electrostatic self-test
3.0 V to 5.25 V single-supply operation
Low power: <2 mA
3500 g shock survival
7.2 mm × 7.2 mm × 3.7 mm package
APPLICATIONS
Industrial vibration/motion sensing
Platform stabilization
Dual-axis tilt sensing
Tracking, recording, and analysis devices
Alarms and security devices
GENERAL DESCRIPTION
The ADIS16003 is a low cost, low power, complete dual-axis
accelerometer with an integrated serial peripheral interface
(SPI). An integrated temperature sensor is also available on the
SPI interface. The ADIS16003 measures acceleration with a full-
scale range of ±1.7 g (minimum), and it can measure both dynamic
acceleration (vibration) and static acceleration (gravity).
The typical noise floor is 110 μg/√Hz, allowing signals below
1 mg (60 Hz bandwidth) to be resolved.
The bandwidth of the accelerometer is set with optional capaci-
tors CX and CY at the XFILT and YFILT pins. Selection of the
two analog input channels is controlled via the serial interface.
An externally driven self-test pin (ST) allows the user to verify
the accelerometer functionality.
The ADIS16003 is available in a 7.2 mm × 7.2 mm × 3.7 mm,
12-terminal LGA package.
FUNCTIONAL BLOCK DIAGRAM
SCLK
DIN
DOU
T
CS
TCS
TEMP
SENSOR
SERIAL
INTERFACE
DUAL-AXIS
±1.7g
ACCELEROMETER
V
CC
C
DC
COM ST
C
Y
C
X
YFILT XFILT
056463-001
Figure 1.
ADIS16003 Data Sheet
Rev. B | Page 2 of 16
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
General Description......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Timing Specifications .................................................................. 4
Circuit and Timing Diagrams..................................................... 5
Absolute Maximum Ratings............................................................ 6
ESD Caution.................................................................................. 6
Pin Configuration and Function Descriptions............................. 7
Typical Performance Characteristics ............................................. 8
Theory of Operation ...................................................................... 11
Accelerometer Data Format...................................................... 11
Self-Test ....................................................................................... 11
Serial Interface............................................................................ 11
Accelerometer Serial Interface.................................................. 11
Temperature Sensor Serial Interface........................................ 12
Power Supply Decoupling......................................................... 12
Setting the Bandwidth ............................................................... 13
Selecting Filter Characteristics: The Noise/Bandwidth Trade-
Off................................................................................................. 13
Applications Information.............................................................. 15
Dual-Axis Tilt Sensor ................................................................ 15
Second Level Assembly ............................................................. 15
Outline Dimensions....................................................................... 16
Ordering Guide .......................................................................... 16
REVISION HISTORY
3/12—Rev. A to Rev. B
Added Accelerometer Data Format Section and Table 6;
Renumbered Sequentially.............................................................. 11
10/07—Rev. 0 to Rev. A
Changes to Features and General Description............................. 1
Added Note 6 to Table 2 .................................................................. 4
Changes to Figure 5.......................................................................... 6
Changes to Serial Interface Section and Layout......................... 11
Changes to Layout .......................................................................... 14
Deleted Figure 24 and Table 11..................................................... 14
Changes to Converting Acceleration to Tilt Section and
Second-Level Assembly Section ................................................... 15
Updated Outline Dimensions....................................................... 16
Changes to Ordering Guide .......................................................... 16
10/05—Revision 0: Initial Version
Data Sheet ADIS16003
Rev. B | Page 3 of 16
SPECIFICATIONS
TA = –40°C to +125°C, VCC = 5 V, CX, CY = 0 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
ACCELEROMETER SENSOR INPUT Each axis
Measurement Range1 ±1.7
g
Nonlinearity % of full scale ±0.5 ±2.5 %
Package Alignment Error ±1.5 Degrees
Alignment Error X sensor to Y sensor ±0.1 Degrees
Cross-Axis Sensitivity ±2 ±5 %
ACCELEROMETER SENSITIVITY Each axis
Sensitivity at XFILT, YFILT 769 820 885 LSB/g
Sensitivity Change due to Temperature2 Delta from 25°C ±8 LSB
ZERO g BIAS LEVEL Each axis
0 g Voltage at XFILT, YFILT 1905 2048 2190 LSB
0 g Offset vs. Temperature ±0.14 LSB/°C
ACCELEROMETER NOISE PERFORMANCE
Noise Density At 25°C 110 μg/√Hz rms
ACCELEROMETER FREQUENCY RESPONSE3
CX, CY Range4 0 10 μF
RFILT Tolerance 24 32 40 kΩ
Sensor Resonant Frequency 5.5 kHz
ACCELEROMETER SELF-TEST
Logic Input Low 0.2 × VCC V
Logic Input High 0.8 × VCC V
ST Input Resistance to COM 30 50 kΩ
Output Change at XOUT, YOUT5 Self-Test 0 to Self-Test 1 323 614 904 LSB
TEMPERATURE SENSOR
Accuracy VCC = 3 V to 5.25 V ±2 °C
Resolution 10 Bits
Update Rate 400 μs
Temperature Conversion Time 25 μs
DIGITAL INPUT
Input High Voltage (VINH) VCC = 4.75 V to 5.25 V 2.4 V
V
CC = 3.0 V to 3.6 V 2.1 V
Input Low Voltage (VINL) VCC = 3.0 V to 5.25 V 0.8 V
Input Current VIN = 0 V or VCC −10 +1 +10 μA
Input Capacitance 10 pF
DIGITAL OUTPUT
Output High Voltage (VOH) ISOURCE = 200 μA, VCC = 3.0 V to 5.25 V VCC − 0.5 V
Output Low Voltage (VOL) ISINK = 200 μA 0.4 V
POWER SUPPLY
Operating Voltage Range 3.0 5.25 V
Quiescent Supply Current fSCLK = 50 kSPS 1.5 2.0 mA
Power-Down Current 1.0 mA
Turn-On Time6 C
X, CY = 0.1 μF 20 ms
1 Guaranteed by measurement of initial offset and sensitivity.
2 Defined as the output change from ambient-to-maximum temperature or ambient-to-minimum temperature.
3 Actual bandwidth response controlled by user-supplied external capacitor (CX, CY).
4 Bandwidth = 1/(2π × 32 kΩ × (2200 pF + C)). For CX, CY = 0 μF, bandwidth = 2260 Hz. For CX, CY = 10 μF, bandwidth = 0.5 Hz. Minimum/maximum values not tested.
5 Self-test response changes as the square of VCC.
6 Larger values of CX, CY increase turn-on time. Turn-on time is approximately 160 × (0.0022 μF + Cx + Cy) + 4 ms, where CX, CY are in μF.
ADIS16003 Data Sheet
Rev. B | Page 4 of 16
TIMING SPECIFICATIONS
TA = −40°C to +125°C, acceleration = 0 g, unless otherwise noted.
Table 2.
Parameter1, 2 V
CC = 3.3 V VCC = 5 V Unit Description
fSCLK3 10 10 kHz min
2 2 MHz max
tCONVERT 14.5 × tSCLK 14.5 × tSCLK
tACQ 1.5 × tSCLK 1.5 × tSCLK Throughput time = tCONVERT + tACQ = 16 tSCLK
t1 10 10 ns min
TCS/CS to SCLK setup time
t24 60 30 ns max
Delay from TCS/CS until DOUT three-state disabled
t34 100 75 ns max Data access time after SCLK falling edge
t4 20 20 ns min Data setup time prior to SCLK rising edge
t5 20 20 ns min Data hold time after SCLK rising edge
t6 0.4 × tSCLK 0.4 × tSCLK ns min SCLK high pulse width
t7 0.4 × tSCLK 0.4 × tSCLK ns min SCLK low pulse width
t85 80 80 ns max
TCS/CS rising edge to DOUT high impedance
t96 5 5 μs typ Power-up time from shutdown
1 Guaranteed by design. All input signals are specified with tr and tf = 5 ns (10% to 90% of VCC) and timed from a voltage level of 1.6 V. The 3.3 V operating range spans
from 3.0 V to 3.6 V. The 5 V operating range spans from 4.75 V to 5.25 V.
2 See Figure 3 and Figure 4.
3 Mark/space ratio for the SCLK input is 40/60 to 60/40.
4 Measured with the load circuit in Figure 2 and defined as the time required for the output to cross 0.4 V or 2.0 V with VCC = 3.3 V and time for an output to cross 0.8 V or
2.4 V with VCC = 5.0 V.
5 t8 is derived from the measured time taken by the data outputs to change 0.5 V when loaded with the circuit in Figure 2. The measured number is then extrapolated
back to remove the effects of charging or discharging the 50 pF capacitor. This means that the time, t8, quoted in the timing characteristics is the true bus relinquish
time of the part and is independent of the bus loading.
6 Shut-down recovery time denotes the time it takes to start producing samples and does not account for the recovery time of the sensor, which is dependent on the
overall bandwidth.
Data Sheet ADIS16003
Rev. B | Page 5 of 16
CIRCUIT AND TIMING DIAGRAMS
05463-002
200µA IOL
200µA IOH
1.6V
T
O OUTPUT
PIN CL
50pF
Figure 2. Load Circuit for Digital Output Timing Specifications
05463-003
SCLK
DOUT
DIN DONTC ZERO ZERO ZERO ADD0 ONE ZERO PM0
4 LE ADI NG ZE ROS
123456 15
16
t
ACQ
t
CONVERT
THREE-STATE THREE-STATE
t
1
t
2
t
5
t
4
t
6
t
7
t
3
t
8
DB11 DB10 DB9 DB0
CS
Figure 3. Accelerometer Serial Interface Timing Diagram
05463-004
TCS
SCLK
DOUT
DIN
1234 11 15 16
THREE-
STATE THREE-STATE
t
1
t
6
t
7
t
3
t
8
DB0
DB9 DB8
LEADING
ZERO
Figure 4. Temperature Serial Interface Timing Diagram
ADIS16003 Data Sheet
Rev. B | Page 6 of 16
ABSOLUTE MAXIMUM RATINGS
Table 4. Package Characteristics
Table 3.
Package Type θJA θ
JC Device Weight
12-Terminal LGA 200°C/W 25°C/W 0.3 grams
Parameter Rating
Acceleration (Any Axis, Unpowered) 3500 g
Acceleration (Any Axis, Powered) 3500 g
VCC −0.3 V to +7.0 V
All Other Pins (COM − 0.3 V) to (VCC + 0.3 V)
Output Short-Circuit Duration
(Any Pin to Common) Indefinite
Operating Temperature Range −40°C to +125°C
Storage Temperature Range −65°C to +150°C
05463-023
1.127
12×
3.594
4×
6.373
2×
3.1865
8×
0.500
12×
0.670
8×
1.797
8×
7.2mm × 7.2mm STACKE D LGA. AL L DIMENS IONS IN mm.
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. Figure 5. Second-Level Assembly Pad Layout
ESD CAUTION
Data Sheet ADIS16003
Rev. B | Page 7 of 16
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
ADIS16003
TOP VIEW
(No t t o S cale)
05463-005
NC
COM
ST
V
CC
SCL
K
CS
NC = NO CONNECT
XFILT
YFILT
NC
9
82
7
1
3
65
4
1012 11
TCS
DOUT
DIN
Figure 6. Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Description
1 TCS Temperature Chip Select. Active low logic input. This input frames the serial data transfer for the
temperature sensor output.
2 DOUT Data Out, Logic Output. The conversion of the ADIS16003 is provided on this output as a serial data stream.
The bits are clocked out on the falling edge of the SCLK input.
3 DIN Data In, Logic Input. Data to be written into the control register of the ADIS16003 is provided on this input and
is clocked into the register on the rising edge of SCLK.
4 COM Common. Reference point for all circuitry on the ADIS16003.
5, 7 NC No Connect.
6 ST Self-Test Input. Active high logic input. Simulates a nominal 0.75 g test input for diagnostic purposes.
8 YFILT Y-Channel Filter Node. Used in conjunction with an optional external capacitor to band limit the ac signal
from the accelerometer.
9 XFILT X-Channel Filter Node. Used in conjunction with an optional external capacitor to band limit the ac signal
from the accelerometer.
10 CS Chip Select. Active low logic input. This input provides the dual function of initiating the accelerometer
conversions on the ADIS16003 and frames the serial data transfer for the accelerometer output.
11 VCC Power Supply Input. The VCC range for the ADIS16003 is from 3.0 V to 5.25 V.
12 SCLK Serial Clock, Logic Input. SCLK provides the serial clock for accessing data from the part and writing serial data
to the control register. This clock input is also used as the clock source for the conversion process of the
ADIS16003.
ADIS16003 Data Sheet
Rev. B | Page 8 of 16
890
770
05463-006
TEMPERATURE (°C)
TYPICAL PERFORMANCE CHARACTERISTICS
40
01900
05463-009
OUTPUT (LSB)
PERCEN TAGE OF POPULATION
125
870
850
830
810
790
–200 20406080100–40
SENSITIVITY (LSB/g)
2200
1900
–40
05463-007
TEMPERATURE (°C)
BIAS LEVEL (LSB)
125
Figure 7. Sensitivity vs. Temperature (ADIS16003 Soldered to PCB)
2150
2100
2050
2000
1950
–20 0 20 40 60 80 100
Figure 8. Zero g Bias vs. Temperature
2200
1900
2.8
05463-008
V
CC
(V)
BIAS LEVEL (LSB)
5.4
2150
2100
2050
2000
1950
3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2
Figure 9. Zero g Bias vs. Supply
30
25
20
15
10
5
1929 1958 1987 2016 2045 2074 2103 2132 2161 2190
35
Figure 10. X-Axis Zero g Bias at 25°C
40
01990
05463-010
OUTPUT (LSB)
PERCEN TAGE OF POPULATION
30
25
20
15
10
5
1929 1958 1987 2016 2045 2074 2103 2132 2161 2190
35
Figure 11. Y-Axis Zero g Bias at 25°C
45
0
05463-011
X-AX IS NOISE DENSITY (µ
g
/ Hz)
PERCEN TAGE OF POPULATION
40
35
30
25
20
15
10
5
60 70 80 90 100 110 120 130 140 150
Figure 12. X-Axis Noise Density at 25°C
Data Sheet ADIS16003
Rev. B | Page 9 of 16
50
0
05463-012
Y-AXIS NOISE DENSITY (mg/ Hz)
PERCEN TAGE OF POPULATION
60
0
05463-015
OUTPUT (LSB)
PERCEN TAGE OF POPULATION
60 70 80 90 100 110 120 130 140 150
40
30
20
10
Figure 13. Y-Axis Noise Density at 25°C
35
0
05463-013
PERCENT SENSIT IVITY (%)
PERCEN TAGE OF POPULATION
–4.5 –3.5 –2.5 –1.5 –0.5 0.5 1.5 2.5 3.5 4.5 5.5
30
25
20
15
10
5
Figure 14. Z vs. X Cross-Axis Sensitivity
40
0
05463-014
PERCENT SENSIT IVITY (%)
PERCEN TAGE OF POPULATION
–4.5 –3.5 –2.5 –1.5 –0.5 0.5 1.5 2.5 3.5 4.5 5.5
35
30
25
20
15
10
5
Figure 15. Z vs. Y Cross-Axis Sensitivity
350 850
50
40
30
20
10
400 450 500 550 600 650 700 750 800
Figure 16. Self-Test at 25°C, VCC at 5.0 V
45
0
05463-016
OUTPUT (LSB)
PERCEN TAGE OF POPULATION
315
40
30
25
20
15
10
5
180 195 210 225 240 255 270 285 300
35
750
450
–40
05463-017
TEMPERATURE (°C)
SELF-TEST LEVEL (LSB/
g
)
Figure 17. Self-Test at 25°C, VCC at 3.3 V
125
700
650
600
550
500
–200 20406080100
Figure 18. Self-Test vs. Temperature, VCC at 5.0 V
ADIS16003 Data Sheet
Rev. B | Page 10 of 16
800
100
05463-018
V
CC
(V)
SELF -TEST L E VEL (LSB)
5.42.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2
700
600
500
400
300
200
Figure 19. Self-Test vs. Supply Voltage
1.8
1.0
05463-019
V
CC
(V)
SUPP LY CURRENT (mA)
5.42.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2
T
A
= +25°C
T
A
= –40° C
1.7
1.6
1.5
1.4
1.3
1.2
1.1
T
A
= +125°C
Figure 20. Supply Current vs. Supply Voltage
90
0
05463-020
CURRENT (µ A)
PERCEN TAGE OF POPULATION
1.75
50
40
30
20
10
3.3V
5V
80
70
60
1.15 1.20 1.25 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70
Figure 21. Supply Current at 25°C
1.0
–1.0
05463-021
SAMPLE RATE (kSPS)
SAMPLING ERRO R ( dB)
1001
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
10
Figure 22. Sampling Error vs. Sample Rate
Data Sheet ADIS16003
Rev. B | Page 11 of 16
THEORY OF OPERATION
The ADIS16003 is a low cost, low power, complete dual-axis
accelerometer with an integrated serial peripheral interface
(SPI) and an integrated temperature sensor whose output is
also available on the SPI interface. The ADIS16003 is capable
of measuring acceleration with a full-scale range of ±1.7 g
(minimum). It can also measure both dynamic acceleration
(vibration) and static acceleration (gravity).
ACCELEROMETER DATA FORMAT
The accelerometer data comes out in a 12-bit, offset-binary format.
See Table 6 for examples of this data format.
Table 6. Acceleration Data Format Examples
Acceleration (g) Decimal Hex Binary
+1.7 3442 0xD72 1101 0111 0010
+2/+820 2050 0x802 1000 0000 0010
+1/+820 2049 0x801 1000 0000 0001
0 2048 0x800 1000 0000 0000
−1/+820 2047 0x7FF 0111 1111 1111
−2/+820 2046 0x7FE 0111 1111 1110
−1.7 654 0x28E 0010 1000 1110
SELF-TEST
The ST pin controls the self-test feature. When this pin is set to VCC,
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 614 LSB) for VCC = 5.0 V. This pin can be
left open-circuit or connected to common in normal use. The ST
pin should never be exposed to a voltage greater than VCC + 0.3 V.
If the system design is such that this condition cannot be
guaranteed (for example, multiple supply voltages are present),
a low VF clamping diode between ST and VCC is recommended.
SERIAL INTERFACE
The serial interface on the ADIS16003 consists of five wire: CS,
TCS, SCLK, DIN, and DOUT. Both accelerometer axes and the
temperature sensor data are available on the serial interface. The
CS and TCS are used to select the accelerometer or temperature
sensor outputs, respectively. CS and TCS cannot be active at the
same time.
The SCLK input accesses data from the internal data registers.
ACCELEROMETER SERIAL INTERFACE
Figure 3 shows the detailed timing diagram for serial interfacing to
the accelerometer in the ADIS16003. The serial clock provides the
conversion clock. CS initiates the data transfer and conversion
process and also frames the serial data transfer for the
accelerometer output. The accelerometer output is sampled on the
second rising edge of the SCLK input after the falling edge of CS.
The conversion requires 16 SCLK cycles to complete. The rising
edge of CS puts the bus back into three-state. If CS remains low,
the next digital conversion is initiated. The details for the control
register bit functions are shown in . Table 7
Accelerometer Control Register
MSB LSB
DONTC ZERO ZERO ZERO ADD0 ONE ZERO PM0
Table 7. Accelerometer Control Register Bit Functions
Bit Mnemonic Comments
7 DONTC Don’t care. Can be 1 or 0.
6 to 4 ZERO These bits should be held low.
3 ADD0 This address bit selects the x-axis or
y-axis outputs. A 0 selects the x-axis;
a 1 selects the y-axis.
2 ONE This bit should be held high.
1 ZERO This bit should be held low.
0 PM0 This bit selects the operation mode for
the accelerometer; set to 0 for normal
operation and 1 for power-down mode.
Power Down
By setting PM0 to 1 when updating the accelerometer
control register, the ADIS16003 goes into a shutdown mode.
The information stored in the control register is maintained
during shutdown. The ADIS16003 changes modes as soon as
the control register is updated. If the part is in shutdown mode
and PM0 is changed to 0, the part powers up on the 16th SCLK
rising edge.
ADD0
By setting ADD0 to 0 when updating the accelerometer control
register, the x-axis output is selected. By setting ADD0 to 1,
the y-axis output is selected.
ZERO
ZERO is defined as the Logic low level.
ONE
ONE is defined as the Logic high level.
DONTC
DONTC is defined as don’t care and can be a low or high
logic level.
Accelerometer Conversion Details
Every time the accelerometer is sampled, the sampling function
discharges the internal CX or CY filtering capacitors by up to 2%
of their initial values (assuming no additional external filtering
capacitors are added). The recovery time for the filter capacitor
to recharge is approximately 10 μs. Therefore, sampling the
accelerometer at a rate of 10 kSPS or less does not induce a
sampling error. However, as sampling frequencies increase
above 10 kSPS, one can expect sampling errors to attenuate
the actual acceleration levels.
ADIS16003 Data Sheet
Rev. B | Page 12 of 16
TEMPERATURE SENSOR SERIAL INTERFACE
Read Operation
Figure 4 shows the timing diagram for a serial read from the
temperature sensor. The TCS line enables the SCLK input.
Ten bits of data and a leading zero are transferred during a read
operation. Read operations occur during streams of 16 clock
pulses. The serial data is accessed in a number of bytes if 10 bits
of data are being read. At the end of the read operation, the
DOUT line remains in the state of the last bit of data clocked
out until TCS goes high, at which time the DOUT line from
the temperature sensor goes three-state.
Write Operation
Figure 4 also shows the timing diagram for the serial write
to the temperature sensor. The write operation takes place at
the same time as the read operation. Data is clocked into the
control register on the rising edge of SCLK. DIN should remain
low for the entire cycle.
Temperature Sensor Control Register
MSB LSB
ZERO ZERO ZERO ZERO ZERO ZERO ZERO ZERO
Table 8. Temperature Sensor Control Register Bit Functions
Bit Mnemonic Comments
7 to 0 ZERO All bits should be held low.
ZERO
ZERO is defined as the Logic low level.
Output Data Format
The output data format for the temperature sensor is twos
complement. Table 9 shows the relationship between the
temperature and the digital output.
Table 9. Temperature Sensor Data Format
Temperature Digital Output (DB9 … DB0)
−40°C 11 0110 0000
−25°C 11 1001 1100
−0.25°C 11 1111 1111
0°C 00 0000 0000
+0.25°C 00 0000 0001
+10°C 00 0010 1000
+25°C 00 0110 0100
+50°C 00 1100 1000
+75°C 01 0010 1100
+100°C 01 1001 0000
+125°C 01 1111 0100
Temperature Sensor Conversion Details
The ADIS16003 features a 10-bit digital temperature sensor
that allows an accurate measurement of the ambient device
temperature to be made.
The conversion clock for the temperature sensor is internally
generated so no external clock is required except when reading
from and writing to the serial port. In normal mode, an internal
clock oscillator runs the automatic conversion sequence. A
conversion is initiated approximately every 350 μs. At this time,
the temperature sensor wakes up and performs a temperature
conversion. This temperature conversion typically takes 25 μs,
at which time the temperature sensor automatically shuts down.
The result of the most recent temperature conversion is available
in the serial output register at any time. Once the conversion is
finished, an internal oscillator starts counting and is designed to
time out every 350 μs. The temperature sensor then powers up
and does a conversion. If the TCS is brought low every 350 μs
(±30%) or less, the same temperature value is output onto the
DOUT line every time without changing.
It is recommended that the TCS line not be brought low every
350 μs (±30%) or less. The ±30% covers process variation. The
TCS should become active (high to low) outside this range.
The device is designed to autoconvert every 350 μs. If the
temperature sensor is accessed during the conversion process,
an internal signal is generated to prevent any update of the
temperature value register during the conversion. This prevents
the user from reading back spurious data. The design of this
feature results in this internal lockout signal being reset only at
the start of the next autoconversion. Therefore, if the TCS line
goes active before the internal lockout signal is reset to its inactive
mode, the internal lockout signal is not reset. To ensure that no
lockout signal is set, bring TCS low at a greater time than 350 μs
(±30%). As a result, the temperature sensor is not interrupted
during a conversion process.
In the automatic conversion mode, every time a read or write
operation takes place, the internal clock oscillator is restarted at
the end of the read or write operation. The result of the conver-
sion is typically available 25 μs later. Reading from the device
before conversion is complete provides the same set of data.
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 ADIS16003
output. If additional decoupling is needed, ferrite beads can be
inserted in the supply line of the ADIS16003. Additionally, a
larger bulk bypass capacitor (in the 1 μF to 22 μF range) can be
added in parallel to CDC.
Data Sheet ADIS16003
Rev. B | Page 13 of 16
SETTING THE BANDWIDTH
The ADIS16003 has provisions for band limiting the
accelerometer. Capacitors can be added at the XFILT pin
and the YFILT pin to implement further low-pass filtering for
antialiasing and noise reduction. The equation for the 3 dB
bandwidth is
f−3dB = 1/(2π(32 kΩ) × (C(XFILT, YFILT) + 2200 pF))
or more simply,
f−3dB = 5 μF/(C(XFILT, YFILT) + 2200 pF)
The tolerance of the internal resistor (RFILT) can vary typically
as much as ±25% of its nominal value (32 kΩ); thus, the
bandwidth varies accordingly.
A minimum capacitance of 0 pF for CXFILT and CYFILT is allowable.
Table 10. Filter Capacitor Selection, CXFILT and CYFILT
Bandwidth (Hz) Capacitor (μF)
1 4.7
10 0.47
50 0.10
100 0.047
200 0.022
400 0.01
2250 0
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, which improves
the resolution of the accelerometer. Resolution is dependent
on the analog filter bandwidth at XFILT and YFILT.
The ADIS16003 has a typical bandwidth of 2.25 kHz with no
external filtering. The analog bandwidth can be further
decreased to reduce noise and improve resolution.
The ADIS16003 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 bandwidth of the accelerometer). The user
should 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 ADIS16003 is determined by
rmsNoise = (110 μg/√Hz) × (√(BW × 1.6))
At 100 Hz, the noise is
rmsNoise = (110 μg/√Hz) × (√(100 × 1.6)) =1.4 mg
Often, the peak value of the noise is desired. Peak-to-peak noise
can only be estimated by statistical methods. Table 11 is useful
for estimating the probabilities of exceeding various peak
values, given the rms value.
Table 11. Estimation of Peak-to-Peak Noise
Peak-to-Peak Value
Percentage of Time Noise Exceeds
Nominal Peak-to-Peak Value (%)
2 × rms 32
4 × rms 4.6
6 × rms 0.27
8 × rms 0.006
ADIS16003 Data Sheet
Rev. B | Page 14 of 16
12
4
1011
65
8 97
3 2 1
12
4
10 11
65
8 97
3 2 1
12
4
1011
65
89 7
321
12
4
10 11
6 5
89 7
321
Top View
Not to Scale
DIG ITAL OUTP UT (IN LS Bs)
X-AXIS: 1229
Y- AXIS : 2048
DIGITAL O UTPUT (IN LSBs)
X-AX IS: 2 867
Y-AXIS: 2048
DIG I TAL OUTPUT (IN LS Bs)
X-AX IS: 204 8
Y-AXIS : 2867
DIG I TAL OUTPUT (IN LS Bs)
X-AX IS: 204 8
Y-AXIS : 1229
DIG ITAL OUTPUT (IN LS Bs)
X-AX IS: 2048
Y- AX IS: 204 8
05463-024
Figure 23. Output Response vs. Orientation
Data Sheet ADIS16003
Rev. B | Page 15 of 16
APPLICATIONS INFORMATION
DUAL-AXIS TILT SENSOR
One of the most popular applications of the ADIS16003 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,
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 its
resolution declines.
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 is converted to an
acceleration that varies between –1 g and +1 g, the output
tilt in degrees is calculated as follows:
PITCH = Asin(AX/1 g)
ROLL = Asin(AY/1 g)
where:
AX is the acceleration along the x-axis.
AY is the acceleration along the y-axis.
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.
SECOND LEVEL ASSEMBLY
The ADIS16003 can be attached to the second level assembly
board using SN63 (or equivalent) or lead-free solder. IPC/
JEDEC J-STD-020 and J-STD-033 provide standard handling
procedures for these types of packages.
ADIS16003 Data Sheet
Rev. B | Page 16 of 16
OUTLINE DIMENSIONS
092407-C
SIDE VI EW
TOP VIEW BOTTOM VIEW
PIN 1
INDICATOR
3.70
MAX
7.20
TYP
1
3
46
7
9
10 12
7.35
MAX
3.594
BSC
(4×)
1.797
BSC
(8×)
5.00
TYP
6 .373
BSC
(2×)
0.200
MIN
(ALL SIDES)
0.373 BSC
(12×)
1.00 BS C
(12×)
0.797 BSC
(8×)
Figure 24. 12-Terminal Land Grid Array [LGA]
(CC-12-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model1 Temperature Range Package Description Package Option
ADIS16003CCCZ −40°C to +125°C 12-Terminal Land Grid Array (LGA) CC-12-1
ADIS16003/PCBZ Evaluation Board
1 Z = RoHS Compliant Part.
©2005-2012 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05463-0-3/12(B)
