AD ADIS16120 Low noise, angular rate sensor Datasheet

Low Noise, Angular Rate Sensor
ADIS16120
FEATURES
GENERAL DESCRIPTION
Low noise density: 0.015o/sec/√Hz
±300o/sec dynamic range
Z-axis, yaw rate response
Calibrated offset and sensitivity
320 Hz bandwidth, adjustable
35 ms turn-on time
Digital self-test
High vibration rejection
High shock survivability
Embedded temperature sensor output
Precision voltage reference output
5 V single-supply operation
−40°C to +85°C temperature range
The ADIS16120 is a low noise, angular rate sensor (gyroscope)
that includes all of the necessary embedded signal conditioning
to provide a low noise, analog output over the complete dynamic
range of ±300o/sec. Factory calibration provides excellent offset
and gain accuracy. The unique design implementation provides
superior stability over variations in temperature, voltage, linear
acceleration, vibration, and next level assembly. The surfacemicromachining manufacturing technology is the same high
volume BiMOS process used by Analog Devices, Inc., for its high
reliability automotive sensor products.
The output signal, RATEOUT, is a voltage proportional to the
angular rate about the axis that is normal to the top surface of
the package. A precision reference and a temperature output are
provided for system-level calibrations and a digital self-test
feature is provided to enable system-level diagnostics. The selftest function electromechanically excites the sensor to verify
proper operation.
APPLICATIONS
Guidance and control
Instrumentation
Inertial measurement units (IMU)
Stabilization
The 35.6 mm × 42.4 mm (plus mounting extensions) package
provides the convenience of a standard geometry 24-pin interface
and four mounting holes for simple installation.
FUNCTIONAL BLOCK DIAGRAM
TEMPOUT
REFOUT
ADIS16120
TEMPERATURE
SENSOR
FILTER
MEMS
ANGULAR
RATE SENSOR
SIGNAL
CONDITIONING
SENSITIVITY
AND
OFFSET
CALIBRATION
RATEOUT
COM
SELF-TEST
05923-001
ST
Figure 1.
Rev. B
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113 ©2006–2007 Analog Devices, Inc. All rights reserved.
ADIS16120
TABLE OF CONTENTS
Features .............................................................................................. 1
Typical Performance Characteristics ..............................................6
Applications....................................................................................... 1
Theory of Operation .........................................................................8
General Description ......................................................................... 1
Setting the Bandwidth ..................................................................8
Functional Block Diagram .............................................................. 1
Self-Test Function .........................................................................8
Revision History ............................................................................... 2
Applications Information .................................................................9
Specifications..................................................................................... 3
Achieving Optimal Noise Performance .....................................9
Absolute Maximum Ratings............................................................ 4
Using the ADIS16120 with a Supply Ratiometric ADC ..........9
Thermal Resistance ...................................................................... 4
Second-Level Assembly ................................................................9
Rate Sensitive Axis ....................................................................... 4
Outline Dimensions ....................................................................... 11
ESD Caution.................................................................................. 4
Ordering Guide .......................................................................... 11
Pin Configuration and Function Descriptions............................. 5
REVISION HISTORY
11/07—Rev. A to Rev. B
Changes to Angle Random Walk Section of Table 1 ................... 3
Changes to Ordering Guide .......................................................... 11
11/06—Rev. 0 to Rev. A
Changes to Specifications Section...................................................3
Added Figure 13 ................................................................................8
7/06—Revision 0: Initial Version
Rev. B | Page 2 of 12
ADIS16120
SPECIFICATIONS
TA = 25°C, VCC = 5 V, angular rate = 0°/sec, COUT = 0 μF, ±1 g, unless otherwise noted.
Table 1.
Parameter
SENSITIVITY
Dynamic Range 2
Initial
Over Temperature 3
Nonlinearity
NULL
Initial Null
Over Temperature
In Run Bias Stability
Angle Random Walk
Turn-On Time
Linear Acceleration Effect
Voltage Sensitivity
NOISE PERFORMANCE
Rate Noise Density 4
FREQUENCY RESPONSE
3 dB Bandwidth 5
Sensor Resonant Frequency
SELF-TEST INPUTS
ST RATEOUT Response 6
Logic 1 Input Voltage
Logic 0 Input Voltage
Input Impedance
TEMPERATURE SENSOR
VOUT at 298 K
Max Current Load on Pin
Scale Factor
OUTPUT DRIVE CAPABILITY
Output Voltage Swing
Capacitive Load Drive 7
2.5 V REFERENCE
Voltage Value
Load Drive to Ground
Load Regulation
Power Supply Rejection
Temperature Drift
POWER SUPPLY
Operating Voltage Range
Quiescent Supply Current
TEMPERATURE RANGE
Specified Performance Grade A
Conditions
Clockwise rotation is positive output
Full-scale range over specified operating conditions
25°C
Min 1
±300
4.95
4.75
Best fit straight line
VS = 4.75 V to 5.25 V
1 σ @ 25°C
1 σ @ 25°C
Power on to ±0.5°/sec of final value, 80 Hz bandwidth
Any axis
VCC = 4.75 V to 5.25 V
2.49
2.4
Typ
Max1
Unit
5
5
0.04
5.05
5.25
Degrees/sec
mV/degrees/sec
mV/degrees/sec
% of FS
2.50
2.51
2.6
0.005
0.9
35
0.05
0.4
25°C
0.015
No external capacitance
320
14
ST pin from Logic 0 to Logic 1
Standard high logic level definition
Standard low logic level definition
To common
175
3.3
270
Degrees/sec/√hr
ms
Degrees/sec/g
Degrees/sec/V
0.020
365
1.7
2.50
IOUT = ±1 mA
50
8.4
0.25
1000
V
μA
mV/K
VS − 0.25
V
pF
2.5
150
5
1
5
2.55
V
μA
mV/mA
mV/V
mV
4.75
5.00
95
5.25
110
V
mA
+85
°C
IOUT = 0 mA, 5 V, 25°C
1
mV
V
V
kΩ
2.45
Source
0 μA < IOUT < 200 μA
4.75 VS to 5.25 VS
Delta from 25°C
Temperature tested to minimum and maximum specifications
Degrees/sec/√Hz
Hz
kHz
3.13
Source to common
Proportional to absolute temperature
V
V
Degrees/sec
−40
All minimum and maximum specifications are guaranteed. Typical specifications are not tested or guaranteed.
Dynamic range is the maximum full-scale measurement range possible, including output swing range, initial offset, sensitivity, offset drift, and sensitivity drift at 4.75 V
to 5.25 V supplies.
3
Specification refers to the maximum extent of this parameter as a worst-case value of TMIN or TMAX, along with long-term effects.
4
Resulting bias stability is <0.01°/sec.
5
Frequency at which response is 3 dB from dc response. See the Setting the Bandwidth section for adjusting this value.
6
Self-test response varies with temperature.
7
The value offered herein assures stability in the output buffer amplifier stage and no degradation of other specified performance parameters.
2
Rev. B | Page 3 of 12
ADIS16120
ABSOLUTE MAXIMUM RATINGS
RATE SENSITIVE AXIS
Parameter
Acceleration (Any Axis, Unpowered, 0.5 ms)
Acceleration (Any Axis, Powered, 0.5 ms)
+VS
Output Short-Circuit Duration (Any Pin to Common)
Operating Temperature Range
Storage Temperature Range
Rating
2000 g
2000 g
−0.3 V to +6.0 V
Indefinite
−55°C to +125°C
−65°C to +150°C
The ADIS16120 is a z-axis rate sensing device that is also called
a yaw rate sensing device. It produces a positive-going change in
the output voltage as a result of clockwise rotation about the
axis, normal to the package top; that is, clockwise when looking
down at the package lid.
RATE
AXIS
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.
Drops onto hard surfaces can cause shocks of greater than
2000 g and exceed the absolute maximum rating of the device.
Care should be exercised in handling to avoid damage.
INAL
ITUD
LONGAXIS
LATER
AL AX
IS
ESD CAUTION
Table 3. Thermal Characteristics
θJC
1.48°C/W
2.5V
GND
Figure 2. Rotational Measurement Orientation
The ADIS16120 provides a temperature output that is representative of the junction temperature. This can be used for
system-level monitoring and power management/thermal
characterization.
θJA
15.7°C/W
4.75V
+
RATE OF
ROTATION
0.25V
THERMAL RESISTANCE
Package Type
24-Lead PCB
Module
RATEOUT
VCC = 5V
Weight
28.5 grams typical
Rev. B | Page 4 of 12
05923-002
Table 2.
ADIS16120
2
4
1
3
6
8
10
12
14
16
18
20
22
24
5
7
9
11
13
15
17
19
21
23
05923-003
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Figure 3. Pin Configuration (Connector-Up View)
Table 4. Pin Function Descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Mnemonic
ST
ST
ST
ST
ST
ST
ST
COM
ST
TEMPOUT
DNC
REFOUT
VCC
COM
VCC
COM
COM
RATEOUT
COM
FILTER
DNC
DNC
COM
DNC
Description
Self-Test.
Self-Test.
Self-Test.
Self-Test.
Self-Test.
Self-Test.
Self-Test.
Power Supply Ground.
Self-Test.
Temperature Sensor Output.
Do Not Connect.
Reference Voltage.
Power Supply.
Power Supply Ground.
Power Supply.
Power Supply Ground.
Power Supply Ground.
Angular Rate Output Signal.
Power Supply Ground.
Filter Input. This is used in conjunction with RATEOUT; see the Setting the Bandwidth section for use.
Do Not Connect.
Do Not Connect.
Power Supply Ground.
Do Not Connect.
Rev. B | Page 5 of 12
ADIS16120
TYPICAL PERFORMANCE CHARACTERISTICS
5.1
2.53
VCC = 5.25V
2.52
4.9
2.51
4.8
NULL (V)
SENSITIVITY (mV/°/s)
5.0
VCC = 5.0V
4.7
2.50
2.49
4.6
2.48
4.5
VCC = 4.75V
100
200
300
400
500
600
RATE (°/s)
2.47
–40
25
55
85
TEMPERATURE (°C)
Figure 4. Gain Sensitivity vs. Angular Rate and Power Supply
5.05
–20
05923-007
0
05923-004
4.4
Figure 7. Null vs. Temperature, VCC = 5 V
0.31
+25°C
5.00
0.29
–40°C
4.90
SELF-TEST (ΔV)
SENSITIVITY (mV/°/s)
4.95
+85°C
4.85
4.80
4.75
0.27
0.25
0.23
4.70
0.21
4.65
100
200
300
400
500
600
RATE (°/s)
0.19
–40
–20
25
55
05923-008
0
05923-005
4.60
85
TEMPERATURE (°C)
Figure 5. Gain Sensitivity vs. Angular Rate and Temperature, VCC = 5 V
Figure 8. Self-Test vs. Temperature, VCC = 5 V
5.05
104
102
100
CURRENT (mA)
VCC = 5V
4.95
4.90
VCC = 5.25V
98
96
VCC = 5.0V
94
92
VCC = 4.75V
90
4.85
4.80
–40
–20
25
55
85
TEMPERATURE (°C)
86
–50
0
50
100
TEMPERATURE (°C)
Figure 6. Gain Sensitivity vs. Temperature @ ±300°/sec
Figure 9. Power Supply Current vs. Temperature and Power Supply
Rev. B | Page 6 of 12
05923-009
88
05923-006
SENSITIVITY (mV/°/s)
5.00
ADIS16120
–60
0.025
fS = 34596Hz
VCC = 5V
16384 SAMPLES
0.023
0.021
0.019
MAGNITUDE (dBV)
NOISE DENSITY (°/s/ Hz)
–70
0.017
0.015
0.013
–80
–90
–100
0.011
–110
0.009
85
–120
TEMPERATURE (°C)
1
1k
10k
100k
100
Figure 12. Noise Density vs. Frequency
MEAN = 0.0147°/s/ Hz
STANDARD DEVIATION = 0.0010
0.1
ROOT ALLAN VARIANCE (°/s)
20
15
10
05923-011
0.0175
0.0171
0.0167
0.0163
0.0159
0.0155
0.0151
0.0147
0.0143
0.0135
0.0131
0.0127
0.0123
0
0.0119
5
0.0115
PERCENTAGE OF POPULATION
100
FREQUENCY (Hz)
Figure 10. Noise Density vs. Temperature, VCC = 5 V
25
10
05923-013
25
05923-014
–40
05923-010
0.007
BIN (°/s/ Hz)
0.01
0.001
0.1
1
10
TAU (Seconds)
Figure 13. Root Allan Variance vs. Integration Time
Figure 11. Noise Histogram
Rev. B | Page 7 of 12
ADIS16120
THEORY OF OPERATION
The offset and sensitivity performance is factory calibrated, and
the internal reference voltage used in this calibration process is
offered for external use. A temperature sensor is also provided
for system level use, where appropriate.
SETTING THE BANDWIDTH
An important trade-off in angular rate measurement applications is the one between total system noise and bandwidth. The
ADIS16120 offers the flexibility to optimize this trade-off at the
system level. The signal processing circuit of the ADIS16120
provides a three-pole, low-pass filter, as shown in Figure 14.
FILTER
820pF
180kΩ
LPF
F1 = 400Hz
±35%
F2 = 1kHz
±10%
180kΩ
OUTPUT
BUFFER
RATEOUT
F3 = 1kHz
±10%
05923-015
LPF
Figure 14. Simplified Filtering Network
The bandwidth of the third stage can be reduced by installing a
single capacitor across the RATEOUT and FILTER pins. Figure 15
shows a relationship for selecting the appropriate capacitor value,
and Table 5 provides bandwidth estimates for standard
capacitor values.
1000
100
10
1
0.1
0.01
0.001
100
1k
10k
100k
1M
10M
100M
CAPACITANCE (pF)
05923-016
The ADIS16120 signal conditioning circuit provides an optimized
filtering network that controls the resonators influence on noise
while supporting a nominal bandwidth of 320 Hz. Another
feature that helps reduce sensitivity to power supply noise is the
integration of approximately 1.8 μF of decoupling capacitance
inside the ADIS16120.
The initial bandwidth of the ADIS16120 is dominated by the first
stage and is dependent on the process variation of the base sensor.
By reducing the bandwidth of the third filter stage, the influence of
the first stage is reduced, and tighter bandwidth tolerances can be
achieved.
BANDWIDTH (Hz)
The base sensor in the ADIS16120 operates on the principle of
a resonator gyroscope. Two polysilicon sensing structures each
contain a dither frame that is electrostatically driven to resonance. This produces the necessary velocity element that creates
a Coriolis force during angular motion. At the two outer extremes
of each frame, orthogonal to the dither motion, are movable
fingers that are placed between fixed fingers to form a capacitive pickoff structure that senses Coriolis acceleration. The
resulting signal is fed to a series of gain and demodulation
stages that produce the representative rate signal output. One
advantage of the core dual-sensor design approach is that it
provides improved rejection of external g-forces and vibration.
Figure 15. Bandwidth vs. Capacitance
Table 5. Nominal Bandwidth for Standard Capacitor Values
C (pF)
BW (Hz)
C (pF)
BW (Hz)
1000
1200
1500
1800
2200
2700
3300
3900
4300
4700
5100
5600
6200
7500
8200
9100
267.3
256.2
244.1
225.5
211.9
192.3
173.2
156.4
148.9
140.4
132.9
124.5
115.6
99.0
92.7
85.5
10,000
12,000
15,000
18,000
22,000
27,000
33,000
39,000
43,000
47,000
51,000
56,000
62,000
75,000
82,000
91,000
78.4
67.1
55.2
46.4
38.8
31.8
26.2
22.2
20.2
18.5
17.1
15.6
14.1
11.7
10.7
9.6
SELF-TEST FUNCTION
The ADIS16120 provides a self-test function that exercises the
mechanical structure of the sensor. To use this function, Pin 1 to
Pin 7 and Pin 9 must be tied together and driven to a high logic
state to activate this function. A continuous self-test does not
damage the device.
Rev. B | Page 8 of 12
ADIS16120
APPLICATIONS INFORMATION
ACHIEVING OPTIMAL NOISE PERFORMANCE
SECOND-LEVEL ASSEMBLY
There are several system level considerations that can have an
impact on the noise and accuracy of the ADIS16120. Understanding and managing these factors can influence the behavior
of any high performance system.
The ADIS16120 is designed to be mounted with the header pins
either facing up (bulkhead mount) or facing down (printed circuit
board mount). In either case, the mating socket should be a Samtec
part number: CLM-112-02-L-D-A or equivalent. This family of
connectors offers multiple configurations for use in mating to the
ADIS16120. Consult the manufacturer reference material if this
connector does not match system level requirements. The recommended pad/hole layout for this socket is shown in Figure 16.
Use the alignment pins identified in this figure, along with either
Figure 17 or Figure 18, to design an appropriate interface for
the ADIS16120. Note that to meet worst-case dimensional
tolerances of the entire package, the header pins extend beyond
the height of the package, requiring the mating PCB to have holes
to prevent the bottoming-out of the ADIS16120 pins. Without
the holes, a bottom-out event places the ADIS16120 under stress,
which can affect accuracy performance. Also, in either mounting
configuration, ensure that the ADIS16120 is firmly mounted to
prevent additional mechanical vibration.
Supply and Common Considerations
The ADIS16120 provides approximately 1.8 μF of decoupling
capacitance. This capacitance is distributed throughout the
device and should be taken into account when considering
potential noise threats on the power supply lines.
Reference Output
The same reference that is used to calibrate the offset performance of the ADIS16120 is made available for system level use.
The REFOUT pin has 1 μF of capacitance, providing a degree
of noise filtering. However, careful use of this pin is necessary,
considering that any noise or level-shifting influences introduce
errors in the output.
Bandwidth Setting
0.4334 [11.0]
If COUT is applied to reduce the bandwidth of the ADIS16120
response, it should be placed close to the device. Long cable
leads and PCB traces may increase the risk of noise introduction.
USING THE ADIS16120 WITH A SUPPLY
RATIOMETRIC ADC
0.019685
[0.5000]
(TYP)
0.0240 [0.610]
0.054 [1.37]
The RATEOUT signal of the ADIS16120 is nonratiometric; that
is, neither the null voltage nor the rate sensitivity is proportional
to the supply. Instead, they are nominally constant for dc supply
changes within the 4.75 V to 5.25 V operating range. If the
ADIS16120 is used with a supply ratiometric ADC, the 2.5 V
output of the ADIS16120 can be converted and used to make
corrections in software for the supply variations.
0.022±
DIA (TYP)
NON PLATED
0.022 DIA THRU HOLE (TYP)
THRU HOLE 2×
NON PLATED THRU HOLE
Rev. B | Page 9 of 12
0.0394 [1.00]
Figure 16. Mating Socket Recommended Pad Layout
Dimensions are shown in inches (millimeters)
05923-017
0.0394 [1.00] 0.1800
[4.57]
ADIS16120
Bulkhead Mounting
Hole locations are shown in Figure 18 for the interface board. Hole
locations for optional alignment posts are also shown in Figure 18.
The hole shown in the interface board for the mounting screw
clearance is sized to provide alignment flexibility. A washer is
required under the screw head for these hole sizes.
Figure 17 provides the hole locations and maximum size for
the bulkhead mount option. When using the bulkhead mount
option, the user can interface to the ADIS16120 header using
a cable or an interface board/cable assembly. This assembly is
not provided. Consult www.analog.com/isensor for the latest
interface/evaluation board options.
37.680 BSC
25 BSC
10 BSC
37.680 BSC
Ø2 BSC 2×
HOLES FOR ALIGNMENT
POSTS AS REQUIRED.
0.736 BSC
2×
7.500 BSC
2×
Ø3 BSC
2×
0.600 BSC
2×
6.340 BSC
2×
05923-019
37 BSC 2×
Ø0.560 BSC 2×
HOLES TO PROVIDE
ACCURATE ALIGNMENT
OF SOCKET (SEE SOCKET
PCB LAYOUT DRAWING).
Figure 18. Interface Board Hole Locations for Bulkhead Mount
Printed Circuit Board Mounting
3.240 BSC 2×
05923-018
31.200 BSC
Figure 19 shows the PCB mount hole locations for correct
alignment. Hole locations for optional alignment posts are also
shown in this diagram.
DRILL AND TAP 4×
MAX 2-56
Figure 17. Bulkhead Mount Attachment Hole Locations
37.680 BSC
25 BSC
2.400 BSC 2×
0.736 BSC
2×
10 BSC
4 BSC
2×
Ø2 BSC 2×
HOLES FOR ALIGNMENT
POSTS AS REQUIRED
7.500
BSC
3.240
BSC
2×
Ø0.560 BSC 2×
HOLES TO PROVIDE
ACCURATE ALIGNMENT 37.600 BSC
2×
OF SOCKET (SEE SOCKET
PCB LAYOUT DRAWING).
37 BSC
2×
3.100 BSC
2.400 BSC
2×
31.200 BSC
Figure 19. Printed Circuit Board Mounting Hole Pattern
Rev. B | Page 10 of 12
R1.200 BSC
8×
05923-020
4 BSC
2×
ADIS16120
OUTLINE DIMENSIONS
42.154
41.900
41.646
37.830
37.680
37.530
32.550
32.350
32.150
2.40 BSC
DETAIL A
25.00 BSC
4.00 BSC
42.654
42.400
42.146
TOP VIEW
37.140
36.990
36.840
3.24 BSC
(2 PLACES)
31.350
31.200
31.050
14.054
13.800
13.546
2.20 BSC
(2 PLACES)
35.854
35.600
35.346
2.00 BSC
DIAMETER
1.00 BSC
(LEAD PITCH)
END VIEW
DETAIL A
092707-B
0.30 SQ
BSC
1.00 BSC
(LEAD PITCH)
3.04
2.84
2.64
Figure 20. ADIS16120 PCB Module with Connector Interface
(ML-24-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model
ADIS16120AML
Temperature Range
−40°C to +85°C
Package Description
PCB Module with Connector Interface
Rev. B | Page 11 of 12
Package Option
ML-24-1
ADIS16120
NOTES
©2006–2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05923-0-11/07(B)
Rev. B | Page 12 of 12