ADXRS645 [ADI]
High Temperature, Vibration Rejecting plus,minus2000temperature/sec Gyroscope;
| 型号： | ADXRS645 |
| 厂家： | 
ADI |
| 描述： | High Temperature, Vibration Rejecting plus,minus2000temperature/sec Gyroscope |
| 文件： | 总10页 (文件大小：323K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
High Temperature, Vibration Rejecting
2000°/sec Gyroscope
Data Sheet
ADXRS645
FEATURES
GENERAL DESCRIPTION
Innovative ceramic vertical mount package can be oriented
for pitch or roll rate response
The ADXRS645 is a high performance angular rate sensor
with excellent vibration immunity for use in high temperature
environments. The ADXRS645 is manufactured using the
Analog Devices, Inc., patented high volume BiMOS surface-
micromachining process with years of proven field reliability.
An advanced, differential, quad sensor design provides superior
acceleration and vibration rejection.
Wide temperature range: −40°C to +175°C
Long life: guaranteed 1000 hours at TA = 175°C
High vibration rejection over wide frequency
10,000 g powered shock survivability
Ratiometric to referenced supply
5 V single-supply operation
Self-test on digital command
Temperature sensor output
The output signal, RATEOUT, is a voltage proportional to the
angular rate about the axis normal to the package lid. The
measurement range is a minimum of 2000°/sec, and may be
extended to 5000°/sec with the addition of a single external
resistor. The output is ratiometric with respect to a provided
reference supply. Other external capacitors are required for
operation.
APPLICATIONS
Down hole measurements for geological exploration
Extreme high temperature industrial applications
Severe mechanical environments
A temperature output is provided for compensation techniques.
Two digital self-test inputs electromechanically excite the sensor
to test proper operation of both the sensor and the signal
conditioning circuits. The ADXRS645 is available in a 8 mm ×
9 mm × 3 mm, 15-lead brazed lead tri in-line package.
FUNCTIONAL BLOCK DIAGRAM
5V
(ADC REF)
100nF
5V
ST2 ST1
TEMP
V
RATIO
ADXRS645
AV
CC
100nF
25kΩ
SELF-TEST
25kΩ
@ 25°C
AGND
DEMOD
MECHANICAL
SENSOR
DRIVE
AMP
AC
AMP
VGA
5V
180kΩ ±1%
V
DD
CHARGE PUMP
AND VOLTAGE
REGULATOR
100nF
PGND
CP1 CP2 CP3 CP4 CP5 SUMJ
RATEOUT
100nF
22nF
22nF
C
OUT
Figure 1.
Rev. A
Document Feedback
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
rightsof third parties that may result fromits 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 andregisteredtrademarks 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
©2014 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
ADXRS645
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Theory of Operation .........................................................................9
Setting Bandwidth.........................................................................9
Temperature Output and Calibration.........................................9
Supply Ratiometricity ...................................................................9
Range Extension ............................................................................9
Self-Test Function .........................................................................9
Continuous Self-Test.....................................................................9
Outline Dimensions....................................................................... 10
Ordering Guide .......................................................................... 10
Applications....................................................................................... 1
General Description......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 4
Rate Sensitive Axis ....................................................................... 4
ESD Caution.................................................................................. 4
Pin Configuration and Function Descriptions............................. 5
Typical Performance Characteristics ............................................. 6
REVISION HISTORY
9/14—Rev. 0 to Rev. A
Changes to Features Section............................................................ 1
Added Usable Life Expectancy Parameter, Table 1...................... 3
7/14—Revision 0: Initial Version
Rev. A | Page 2 of 10
Data Sheet
ADXRS645
SPECIFICATIONS
All minimum and maximum specifications are guaranteed. Typical specifications are not guaranteed. TA = 25°C, VS = AVCC = VDD = 5 V,
V
RATIO = AVCC, angular rate = 0°/sec, bandwidth = 80 Hz (COUT = 0.01 µF), and IOUT = 100 µA, unless otherwise noted.
Table 1.
Parameter
Test Conditions/Comments
Min
Typ
2000
Max
Unit
SENSITIVITY1
Measurement Range2, 3
Initial
Clockwise rotation is positive output
°/sec
mV/°/sec
%
%
% of FS
TA = 25°C
1
Temperature Drift
Uncompensated, −40°C to +150°C4
Uncompensated, 150°C to 175°C
Best fit straight line
5
−35
0.1
Nonlinearity
NULL1
Initial
Temperature Drift
TA = 25°C
2.4
2.5
50
150
0.1
0.0006
2.6
V
Uncompensated, −40°C to +150°C4
Uncompensated, 150°C to 175°C
Any axis
°/sec
°/sec
°/sec/g
°/sec/g2
Linear Acceleration Effect
Vibration Rectification
NOISE PERFORMANCE
Rate Noise Density
25 g rms, 50 Hz to 5 kHz
TA ≤ 25°C
TA = 25°C, 1 minute to 1 hour in-run
TA = 150°C, 1 minute to 1 hour in-run
0.25
100
150
°/sec/√Hz
°/hr
°/hr
Resolution Floor
FREQUENCY RESPONSE
Bandwidth ( 3 dB)5
Sensor Resonant Frequency
SELF-TEST1
No external filter
2000
17.5
Hz
kHz
15.5
20
ST1 RATEOUT Response
ST2 RATEOUT Response
ST1 to ST2 Mismatch6
Logic 1 Input Voltage
Logic 0 Input Voltage
Input Impedance
ST1 pin from Logic 0 to Logic 1
ST2 pin from Logic 0 to Logic 1
−1300
1300
2
°/sec
°/sec
%
V
V
3.3
40
1.7
100
To common
50
kΩ
TEMPERATURE SENSOR1
VTEMP at 25°C
Load = 10 MΩ
25°C, VRATIO = 5 V
2.3
2.4
9
2.5
V
Scale Factor7
mV/°C
ms
TURN-ON TIME8
Power on to 2°/sec of final with CP5 = 100 nF
50
OUTPUT DRIVE CAPABILITY
Current Drive
Capacitive Load Drive
POWER SUPPLY
For rated specifications
200
1000
µA
pF
Operating Voltage (VS)
Quiescent Supply Current
TEMPERATURE RANGE
Specified Performance
LIFESPAN
4.75
5.00
3.5
5.25
V
mA
−40
+175
°C
Usable Life Expectancy
TA = 175°C
1000
Hours
1 Parameter is linearly ratiometric with VRATIO
.
2 Measurement range is the maximum range possible, including output swing range, initial offset, sensitivity, offset drift, and sensitivity drift at 5 V supplies.
3 Measurement range can be extended to as much as 5000°/s by adding a single 120 kΩ resistor between the RATEOUT and SUMJ pins.
4 Maximum deviation from +25°C to −40°C or +25°C to +150°C, see the Typical Performance Characteristics section for typical behavior over temperature.
5 Adjusted by the external capacitor, COUT. Reducing bandwidth below 0.01 Hz does not result in further noise improvement.
6 Self-test mismatch is described as (ST2 + ST1)/((ST2 − ST1)/2).
7 Scale factor for a change in temperature from 25°C to 26°C. VTEMP is ratiometric to VRATIO
8 Based on characterization.
.
Rev. A | Page 3 of 10
ADXRS645
Data Sheet
ABSOLUTE MAXIMUM RATINGS
RATE SENSITIVE AXIS
Table 2.
The ADXRS645 produces a positive output voltage for clockwise
rotation about the axis normal to the package lid, that is,
clockwise when looking at the package lid.
Z-AXIS
Parameter
Acceleration (Any Axis, 0.5 ms)
Unpowered
Powered
VDD, AVCC
VRATIO
Rating
10,000 g
10,000 g
−0.3 V to +6.6 V
AVCC
ST1, ST2
AVCC
Output Short-Circuit Duration (Any Pin to
Common)
Operating Temperature Range
Storage Temperature Range
Indefinite
RATE
AXIS
−55°C to +175°C
−65°C to +185°C
Figure 2. RATEOUT Signal Increases with Clockwise Rotation
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
ESD CAUTION
Drops onto hard surfaces can cause shocks of greater than
10,000 g and can exceed the absolute maximum rating of the
device. Exercise care in handling to avoid damage.
Rev. A | Page 4 of 10
Data Sheet
ADXRS645
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
ST1
A
ST2
B
TEMP
C
3
2
A
B
C
D
E
F
1
A
B
C
D
E
F
ADXRS645
TOP VIEW
(Not to Scale)
Figure 3. Pin Configuration (Top View)
Figure 4. Pin Configuration (3D View)
Table 3. Pin Function Descriptions
Pin Number
Mnemonic
Description
A1
A2
A3
B1
B2
B3
C1
C2
C3
D1
D2
E1
E2
F1
F2
CP3
CP5
ST1
CP4
VDD
ST2
CP1
PGND
TEMP
CP2
RATEOUT
AVCC
SUMJ
AGND
VRATIO
Charge Pump Capacitor, 22 nF
HV Filter Capacitor, 100 nF
Positive Self-Test
Charge Pump Capacitor, 22 nF
Positive Charge Pump Supply
Negative Self-Test
Charge Pump Capacitor, 22 nF
Charge Pump Supply Return
Temperature Voltage Output
Charge Pump Capacitor, 22 nF
Rate Signal Output
Positive Analog Supply
Output Amplifier Summing Junction
Analog Supply Return
Reference Supply for Ratiometric Output
Rev. A | Page 5 of 10
ADXRS645
Data Sheet
TYPICAL PERFORMANCE CHARACTERISTICS
2700
2650
2600
2550
2500
2450
2400
50
40
30
20
10
0
–50
0
50
100
150
200
200
200
TEMPERATURE (°C)
NULL OUTPUT (mV)
Figure 5. Null Output at 25°C
Figure 8. Null Output Over Temperature
1.2
1.0
0.8
0.6
0.4
0.2
0
50
45
40
35
30
25
20
15
10
5
0
–50
0
50
100
150
TEMPERATURE (°C)
SENSITIVITY (mV/°/sec)
Figure 6. Sensitivity at 25°C
Figure 9. Sensitivity Over Temperature
0
–200
35
30
25
20
15
10
5
–400
–600
–800
–1000
–1200
–1400
–1600
–1800
–2000
0
–50
0
50
100
150
TEMPERATURE (°C)
ST1 OUTPUT CHANGE (°/sec)
Figure 7. ST1 Output Change at 25°C (VRATIO = 5 V)
Figure 10. ST1 Output Over Temperature
Rev. A | Page 6 of 10
Data Sheet
ADXRS645
2000
1800
1600
1400
1200
1000
800
40
35
30
25
20
15
10
5
600
400
200
0
–50
0
0
50
100
150
200
TEMPERATURE (°C)
ST2 OUTPUT CHANGE (°/sec)
Figure 14. ST2 Output Over Temperature
Figure 11. ST2 Output Change at 25°C (VRATIO = 5 V)
10000
1000
100
10
45
40
35
30
25
20
15
10
5
AVERAGE
+1σ
–1σ
1
0.01
0
0.1
1
10
100
1000
10000
AVERAGING TIME (Seconds)
SELF-TEST MISMATCH (%)
Figure 12. Self-Test Mismatch at 25°C (VRATIO = 5 V)
Figure 15. Allan Variance at 25°C vs. Averaging Time
40
35
30
25
20
15
10
5
4.0
3.5
3.0
2.5
2.0
1.5
0
–50
0
50
100
150
200
TEMPERATURE (°C)
V
OUTPUT (V)
TEMP
Figure 16. VTEMP Output Over Temperature
Figure 13. VTEMP Output at 25°C
Rev. A | Page 7 of 10
ADXRS645
Data Sheet
35
30
25
20
15
10
5
0
–3
0
–30
–60
–90
–120
–150
–6
–9
–12
–15
–18
–180
10
0
0.1
1
FREQUENCY (kHz)
CURRENT CONSUMPTION (mA)
Figure 17. Current Consumption at 25°C (VRATIO = 5 V)
Figure 19. Typical Rate and Phase Response vs. Frequency (COUT = 470 pF
with a Series RC Low-Pass Filter of 3.3 kΩ and 22 nF)
1
0.04
0.03
0.02
0.01
0
0.1
0.01
0.02
0.03
0.04
0.05
0.06
0.01
0.001
0.1
1
10
100
1k
10k
–2000
–1000
0
1000
2000
FREQUENCY (Hz)
RATE (°/sec)
Figure 18. Typical Noise Spectral Density (COUT = 0.01 µF)
Figure 20. Typical Output Nonlinearity
Rev. A | Page 8 of 10
Data Sheet
ADXRS645
THEORY OF OPERATION
The ADXRS645 operates on the principle of a resonator gyroscope.
Two polysilicon sensing structures each contain a dither frame that
is electrostatically driven to resonance, producing the necessary
velocity element to produce a Coriolis force during angular rate.
At two of the outer extremes of each frame, orthogonal to the
dither motion, are movable fingers that are placed between
fixed pickoff fingers to form a capacitive pickoff structure that
senses Coriolis motion. The resulting signal is fed to a series of
gain and demodulation stages that produce the electrical rate
signal output. The dual sensor design rejects external g-forces and
vibration. Fabricating the sensor with the signal conditioning
electronics preserves signal integrity in noisy environments.
SUPPLY RATIOMETRICITY
The RATEOUT, ST1, ST2, and TEMP signals of the ADXRS645
are ratiometric to the VRATIO voltage, that is, the null voltage, rate
sensitivity, and temperature outputs are proportional to VRATIO
.
Therefore, it is most easily used with a supply ratiometric analog-
to-digital converter (ADC), which results in self cancellation of
errors due to minor supply variations. There is some small, usually
negligible, error due to nonratiometric behavior. Note that, to
guarantee full rate range, VRATIO must not be greater than AVCC
.
RANGE EXTENSION
The ADXRS645 scale factor can be reduced to extend the
measurement range to as much as 5000°/sec by adding a single
120 kΩ resistor between the RATEOUT and SUMJ pins. If an
external resistor is added between the RATEOUT and SUMJ
pins, proportionally increase COUT to maintain correct
bandwidth (that is, if adding a 180 kΩ resistor, double COUT).
The electrostatic resonator requires 15 V for operation. Because
only 5 V is typically available in most applications, a charge
pump is included on chip. If an external 17 V to 22 V supply is
available, the two capacitors on CP1 to CP4 can be omitted, and
this supply can be connected to CP5 (Pin A2) through a 1 kΩ
series resistor. Do not ground CP5 when power is applied to the
ADXRS645. No damage occurs, but under certain conditions,
the charge pump may fail to start up after the ground is
SELF-TEST FUNCTION
The ADXRS645 includes a self-test feature that actuates each of
the sensing structures and associated electronics in the same
manner, as if subjected to angular rate. It is activated by standard
logic high levels applied to ST1 (Pin A3), ST2 (Pin B3), or both.
ST1 causes the voltage at RATEOUT to change about −1.3 V,
and ST2 causes an opposite change of +1.3 V. The self-test
response follows the viscosity temperature dependence of the
package atmosphere, approximately 0.25%/°C.
removed without first removing power from the ADXRS645.
SETTING BANDWIDTH
The external capacitor, COUT, is used in combination with the
on-chip resistor, ROUT, to create a low-pass filter to limit the
bandwidth of the ADXRS645 rate response. The −3 dB
frequency set by ROUT and COUT is
Activating both ST1 and ST2 simultaneously is not damaging.
ST1 and ST2 are fairly closely matched ( 1%), but actuating
both simultaneously may result in a small apparent null bias
shift proportional to the degree of self-test mismatch.
f
OUT = 1/(2 × π × ROUT × COUT)
This frequency can be well controlled because ROUT has been
trimmed during manufacturing to be 180 kΩ 1%. Any external
resistor applied between the RATEOUT pin (D2) and SUMJ pin
(E2) results in ROUT = (180 kΩ × REXT)/(180 kΩ × REXT).
ST1 and ST2 are activated by applying a voltage equal to VRATIO
to the ST1 pin and the ST2 pin. The voltage applied to ST1 and
In general, an additional filter (in either hardware or software)
is added to attenuate high frequency noise arising from
demodulation spikes at the 18 kHz resonant frequency of the
gyroscope. An RC output filter consisting of a 3.3 kΩ series
resistor and 22 nF shunt capacitor (2.2 kHz pole) is recommended.
ST2 must never be greater than AVCC
.
CONTINUOUS SELF-TEST
The on-chip integration of the ADXRS645 gives it higher reliability
than is obtainable with any other high volume manufacturing
method. In addition, it is manufactured under a mature BiMOS
process that has field proven reliability. As an additional failure
detection measure, power-on self-test can be performed.
However, some applications may warrant continuous self-test
while sensing rate.
TEMPERATURE OUTPUT AND CALIBRATION
It is common practice to temperature calibrate gyroscopes to
improve their overall accuracy. The ADXRS645 has a temperature
proportional voltage output that provides input to such a calibration
method. The temperature sensor structure is shown in Figure 21.
The voltage at TEMP (Pin C3) is nominally 2.4 V at 25°C, and
V
RATIO = 5 V. The temperature coefficient is ~9 mV/°C at 25°C.
Although the TEMP output is highly repeatable, it has only
modest absolute accuracy.
V
RATIO
V
TEMP
R
R
FIXED
TEMP
Figure 21. Temperature Sensor Structure
Rev. A | Page 9 of 10
ADXRS645
Data Sheet
OUTLINE DIMENSIONS
8.20
8.00
7.80
SIDE VIEW
3.30
2.85
2.40
FRONT VIEW
BACK VIEW
5.00
BSC
9.20
9.00
8.80
0.30
6.30
0.25
0.20
6.00
5.70
1.30
BSC
0.625
BSC
3.00
BSC
2.00
BSC
1.48
1.35
1.22
0.55
0.50
0.45
2.83
2.70
2.57
TOP VIEW
Figure 22. 15-Lead Brazed Lead Tri In-line Package [BL_TIP]
(DY-15-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model1
Temperature Range
Package Description
Package Option
ADXRS645HDYZ
−40°C to +175°C
15-Lead Brazed Lead Tri In-line Package [BL_TIP]
DY-15-1
1 Z = RoHS Compliant Part.
©2014 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D11958-0-9/14(A)
Rev. A | Page 10 of 10
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