AD AD22304

±80°/s Single Chip Yaw Rate
Gyro with Signal Conditioning
AD22304
FEATURES
GENERAL DESCRIPTION
Complete rate gyroscope on a single chip
Z-axis (yaw rate) response
High vibration rejection over wide frequency
0.05°/s/√Hz noise
2000 g powered shock survivability
Self-test on digital command
Temperature sensor output
Precision voltage reference output
Absolute rate output for precision applications
5 V single-supply operation
Ultrasmall and light (< 0.15 cc, < 0.5 gram)
The AD22304 is a complete angular rate sensor (gyroscope)
that uses Analog Devices’ surface-micromachining process to
make a functionally complete and low cost angular rate sensor
integrated with all of the required electronics on one chip.
The manufacturing technique for this device is the same high
volume BIMOS process used for high reliability automotive
airbag accelerometers.
The output signal, RATEOUT (1B, 2A), is a voltage proportional to the angular rate about the axis normal to the top surface of the package (see Figure 2). A single external resistor
can be used to lower the scale factor. An external capacitor is
used to set the bandwidth. Other external capacitors are required for operation (see Figure 22).
APPLICATIONS
GPS navigation systems
Vehicle stability control
Inertial measurement units
Guidance and control
Platform stabilization
A precision reference and a temperature output are also provided for compensation techniques. Two digital self-test inputs
electromechanically excite the sensor to test the operation of
both sensors and the signal conditioning circuits. The AD22304
is available in a 7 mm × 7 mm × 3 mm BGA surface-mount
package.
FUNCTIONAL BLOCK DIAGRAM
+ 5V –
100nF
3A
ST1
5G
4G
SELF
TEST
SUMJ
1C
CMID
AGND
2G
1F
AVCC
ST2
COUT
100nF
1D
ROUT
CORIOLIS SIGNAL CHANNEL
RSEN2
RSEN1
180kΩ 1%
π DEMOD
RATE
SENSOR
≈9kΩ ±35% ≈9kΩ ±35%
1B
2A
RESONATOR LOOP
1E
2.5V REF
RATEOUT
2.5V
PTAT
3G TEMP
12V
CHARGE PUMP/REG.
PDD
4A
CP2
AD22304
ADXRS150
5A
22nF
7E
6G
7F
PGND
CP1
6A
7B
CP4
7C
CP3
7D
CP5
47nF
100nF
22nF
Figure 1.
Rev. 0-Preliminary
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: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved.
AD22304
TABLE OF CONTENTS
Specifications ............................................................................3
Increasing Measurement Range ..........................................10
Absolute Maximum Ratings......................................................4
Temperature Output and Calibration ...................................10
Rate Sensitive Axis................................................................4
Using the AD22304 with a Supply-Ratiometric ADC........10
ESD Caution..........................................................................4
Null Adjustment ..................................................................10
Pin Configurations and Function Descriptions..........................5
Self-Test Function ...............................................................10
Typical Performance Characteristics .........................................6
Continuous Self-Test ...........................................................10
Theory of Operation ..................................................................9
Acceleration Sensitivity ......................................................10
Supply and Common Considerations ....................................9
Outline Dimensions ................................................................12
Setting Bandwidth .................................................................9
Ordering Guide....................................................................12
REVISION HISTORY
5/6/05—Rev A
5/6/05—Rev B – Corrected part number in Ordering Guide
9/23/05—Rev C – Corrected datasheet title
Rev. C | Page 2 of 12
AD22304
SPECIFICATIONS
@TA = 25°C, AVCC = 4.75V to 5.25V, bandwidth = 80 Hz (COUT = 0.01 µF), angular rate = 0°/s, ±1g, unless otherwise noted.
Table 1.
Parameter
SENSITIVITY
Dynamic Range2
Sensitivity
Over Temperature3
Nonlinearity
Voltage Sensitivity
NULL
Initial Null
Null Drift over Temperature3
Turn-On Time
Linear Acceleration Effect
Voltage Sensitivity
NOISE PERFORMANCE
Rate Noise Density
FREQUENCY RESPONSE
3 db Bandwidth4 (User Selectable)
Sensor Resonant Frequency
SELF TEST
ST1 RATEOUT Response5
ST2 RATEOUT Response5
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
2.5 V REFERENCE
Voltage Value
Load Drive to Ground
Load Regulation
Power Supply Rejection
3
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 specifications range
TA = -40°C to +85°C
Delta from 25°C
Best fit straight line
AVCC = 4.75 V to 5.25 V
Min1
AD22304
Typ
Max1
±80
11.25
12.5
TA=25°C
Delta from 25°C
Power on to ±½°/s of final
Any axis
AVCC = 4.75 V to 5.25 V
2.00
13.75
±10
0.1
0.7
35
0.2
1
@25°C
0.05
°/s/√Hz
22 nF as comp cap (see the Applications section)
40
14
Hz
kHz
–400
+400
3.3
–660
+660
3.00
±250
°/s
mV/°/s
%
% of FS
%/V
V
mV
ms
°/s/g
°/s/V
ST1 pin from Logic 0 to 1, –40°C to +85°C
ST2 pin from Logic 0 to 1, –40°C to +85°C
Standard high logic level definition
Standard low logic level definition
To common
2.50
Unit
–1000
+1000
1.7
50
2.50
Source to common
Proportional to absolute temperature
IOUT = ±100 µA
50
8.4
0.25
1000
V
µA
mV/°K
VS – 0.25
V
pF
2.45
2.5
200
5.0
1.0
5.0
2.55
V
µA
mV/mA
mV/V
mV
4.75
5.00
6.0
5.25
8.0
V
mA
+85
°C
Source
0 < IOUT < 200 µA
4.75 VS to 5.25 VS
Delta from 25°C
–40
1
mV
mV
V
V
kΩ
All min and max 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.
3
Specification refers to the maximum extent of this parameter as a worst-case value at TMIN or TMAX.
4
Frequency at which response is 3 dB down from dc response with specified compensation capacitor value. Internal pole forming resistor is 180 kΩ. See the
Setting Bandwidth section.
5
Self-test response varies with temperature. See the Self-Test Function section for details.
2
Rev. C | Page 3 of 12
AD22304
ABSOLUTE MAXIMUM RATINGS
Table 2.
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
RATE SENSITIVE AXIS
Rating
2000 g
2000 g
–0.3 V to +6.0
V
This is a Z-axis rate-sensing device that is also called a yaw
rate sensing device. It produces a positive going output voltage
for clockwise rotation about the axis normal to the package top,
i.e., clockwise when looking down at the package lid.
RATEOUT
RATE
AXIS
Indefininte
VCC = 5V
LONGITUDINAL
AXIS
–55°C to
+125°C
–65°C to
+150°C
4.75V
2.5V
7
A1
ABCDEFG
LATERAL AXIS
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only and 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.
RATE IN
1
0.25V
GND
Figure 2. RATEOUT Signal Increases with Clockwise Rotation
Applications requiring more than 200 cycles to MIL-STD-883
Method 1010 Condition B (–55°C to +125°C) require underfill
or other means to achieve this requirement.
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.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 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. C | Page 4 of 12
AD22304
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
PGND
PDD
CP5
CP3
CP4
7
6
ST1
CP1
5
ST2
CP2
4
AVCC 3
TEMP
2
AGND
G
F
2.5V
CMID
E
D
RATEOUT
SUMJ
C
B
A
Figure 3. BGA-32 (Bottom View)
Table 3. Pin Function Descriptions
Pin No.
6D, 7D
6A, 7B
6C, 7C
5A, 5B
4A, 4B
3A, 3B
1B, 2A
1C, 2C
1D, 2D
1E, 2E
1F, 2G
3F, 3G
4F, 4G
5F, 5G
6G, 7F
6E, 7E
Mnemonic
CP5
CP4
CP3
CP1
CP2
AVCC
RATEOUT
SUMJ
CMID
2.5V
AGND
TEMP
ST2
ST1
PGND
PDD
Description
HV Filter Capacitor—47 nF
Charge Pump Capacitor—22 nF
Charge Pump Capacitor—22 nF
Charge Pump Capacitor—22 nF
Charge Pump Capacitor—22 nF
+ Analog Supply
Rate Signal Output
Output Amp Summing Junction
HF Filter Capacitor—100 nF
2.5 V Precision Reference
Analog Supply Return
Temperature Voltage Output
Self-Test for Sensor 2
Self-Test for Sensor 1
Charge Pump Supply Return
+ Charge Pump Supply
Rev. C | Page 5 of 12
03226-B-003
1
AD22304
TYPICAL PERFORMANCE CHARACTERISTICS
NO PRIOR WARMUP, 0.6Hz SAMPLING
4.5
2.570
4.0
2.565
3.0
2.560
RATEOUT (V)
RATEOUT (V)
3.5
2.5
2.0
1.5
1.0
0
–0.05
0
0.05
0.10
TIME (sec)
0.15
0.20
2.550
2.545
03226-B-004
0.5
2.555
2.540
0.25
0
Figure 4. Rate Sensing Start-Up Time
90
TIME (sec)
120
180
150
Figure 7. Null Settling Time
0.07
2.570
0.06
2.565
0.05
2.560
0.04
2.555
°/s
RATEOUT (V)
60
30
0.03
2.550
0.02
2.545
0.01
0
2.540
0
600
1200
1800
TIME (sec)
2400
3000
1
3600
Figure 5. Null Stability for 1 Hour
100
10
TIME (sec)
Figure 8. Root Allan Variance vs. Averaging Time
2.5040
3.4
3.2
2.5035
3.0
V2.5 (V)
VTEMP (V)
2.5030
2.8
2.6
2.4
2.5025
2.5020
2.2
2.5015
2.0
2.5010
1.8
–55
–30
–5
45
20
TEMPERATURE (°C)
70
–40 –30 –20 –10
95
Figure 6. Temperature Sensor Output
20 30
0 10
40
TEMPERATURE (°C)
50
60
70
80
Figure 9. 2.5 V Voltage Reference vs. Temperature
Rev. C | Page 6 of 12
AD22304
@ BW = 40 Hz, Typical Vibration Characteristics, 10 g Flat Band, 20 Hz to 2 kHz
PACKAGE LATERAL AXIS (0.5s Average)
2.500
2.490
2.490
RATEOUT (V)
RATEOUT (V)
PACKAGE LATERAL AXIS (1/60 SEC SAMPLE RATE)
2.500
2.480
2.470
2.460
0g
2.480
10g
2.470
2.460
2.450
2.450
0
5
TIME (sec)
10
5
TIME (sec)
0
Figure 10. 10 g Random Vibration in Package-Lateral Axis Orientation
Figure 13. 10 g Random Vibration in Package-Lateral Axis Orientation
PACKAGE LONGITUDINAL AXIS (1/60 SEC SAMPLING RATE)
PACKAGE LONGITUDINAL AXIS (0.5s Average)
2.500
2.500
2.490
2.490
RATEOUT (V)
RATEOUT (V)
10
2.480
2.470
2.460
10g
2.480
0g
2.470
2.460
2.450
2.450
0
5
TIME (sec)
10
5
TIME (sec)
0
Figure 11. 10 g Random Vibration in Package-Longitudinal Axis Orientation
10
Figure 14. 10 g Random Vibration in Package-Longitudinal Axis Orientation
RATE AXIS (1/60 SEC SAMPLING RATE)
RATE AXIS (0.5s Average)
2.500
2.500
2.490
2.490
RATEOUT (V)
RATEOUT (V)
10g
2.480
2.470
2.460
2.480
0g
2.470
2.460
2.450
0
5
TIME (sec)
10
Figure 12. 10 g Random Vibration in Rate Axis Orientation
2.450
0
5
TIME (sec)
10
Figure 15. 10 g Random Vibration in Rate Axis Orientation
Rev. C | Page 7 of 12
AD22304
Behavior under Various Shock Test Conditions
Figure 16. Shock Test 100 g, 5 ms in Lateral Axis (40 Hz)
Figure 19. Shock Test 100 g, 5 ms in Longitudinal Axis (40 Hz)
Figure 17. Hi-g Shock Test in Lateral Axis (40 Hz)
Figure 20. Hi-g Shock Test, Lateral Axis, 10× Time Base (40 Hz)
Figure 18. Hi-g Shock in Rate Axis (40 Hz)
Figure 21. Hi-g Shock, Rate Axis, BW Reduced to 8 Hz
Rev. C | Page 8 of 12
AD22304
THEORY OF OPERATION
The electrostatic resonator requires 14 V to 16 V for operation.
Since only 5 V is typically available in most applications, a
charge pump is included on-chip. If an external 14 V to 16 V
supply is available, the two capacitors on CP1–CP4 can be
omitted, and this supply can be connected to CP5 (Pin 7D) with
a 100 nF decoupling capacitor in place of the 47 nF.
After the demodulation stage, there is a single-pole low-pass
filter consisting of an internal 9 kΩ resistor (RSEN1) and an
external user-supplied capacitor (CMID). A CMID capacitor of
100 nF sets a 400 Hz ± 35% low-pass pole and is used to limit
high frequency artifacts before final amplification. The bandwidth limit capacitor, COUT, sets the pass bandwidth (see Figure
23 and the Setting Bandwidth section).
Figure 22 shows the recommended connections for the AD22304
where both AVCC and PDD have a separate
decoupling capacitor. These should be placed as close to their
respective pins as possible before routing to the system analog
supply. This will minimize the noise injected by the charge
pump that uses the PDD supply.
It is also recommended to place the charge pump capacitors
connected to the CP1–CP4 pins as close to the part as possible.
These capacitors are used to produce the on-chip high voltage
supply switched at the dither frequency at approximately
14 kHz. Care should be taken to ensure that there is no more
than 50 pF of stray capacitance between CP1–CP4 and ground.
Surface-mount chip capacitors are suitable as long as they are
rated for over 15 V.
+
2G
3A
ST2 4G
SELF
TEST
CP3 CP5
7B
7C
PDD
7D
7E
5V
7F
ST1
4A
4G
ST2
3G
TEMP
2G
RATEOUT SUMJ
1E
CMID
2.5V
7D
CP4 CP3 CP5
22nF
47nF
22nF
External capacitors CMID and COUT are used in combination
with on-chip resistors to create two low-pass filters to limit the
bandwidth of the AD22304’s rate response. The –3 dB
frequency set by ROUT and COUT is
100nF
1D
6A 7B 7C
SETTING BANDWIDTH
3A
1C
6G 7F
CP1
Figure 23. Block Diagram with External Components
5G
1B
1E 2.5V
100nF
6G
2A
SUMJ
12V
PGND
AD22304
ADXRS150
5A
AVCC
1C
3G TEMP
CHARGE
PUMP/REG.
PGND
22nF
CP2
1D
PTAT
47nF
CP1
CMID
2.5V REF
PDD
7E
4A 5A
6A
1F
ROUT
CORIOLIS
180kΩ 1%
SIGNAL CHANNEL
RSEN1 RSEN2
π
RATE
DEMOD
1B
SENSOR
RATE≈9kΩ ±35%
2A OUT
RESONATOR LOOP
CP2
CP4
COUT
100nF
AGND
AVCC
ST1 5G
100nF
22nF
–
5V
100nF
03226-B-023
The AD22304 operates on the principle of a resonator gyro.
Two polysilicon sensing structures each contain a dither frame,
which is electrostatically driven to resonance. This produces
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, movable fingers 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.
fOUT = 1/ (2 × π × ROUT × COUT )
1F
AGND
and can be well controlled since ROUT has been trimmed during
manufacturing to be 180 kΩ ± 1%. Any external resistor applied between the RATEOUT (1B,2A) and SUMJ (1C,2C) pins
results in
100nF
COUT = 22nF
NOTE THAT INNER ROWS/COLUMNS OF PINS HAVE BEEN OMITTED
FOR CLARITY BUT SHOULD BE CONNECTED IN THE APPLICATION.
ROUT = (180 kΩ× REXT )/ (180 kΩ + REXT )
Figure 22. Example Application Circuit (Top View)
SUPPLY AND COMMON CONSIDERATIONS
Only power supplies used for supplying analog circuits are
recommended for powering the AD22304. High frequency
noise and transients associated with digital circuit supplies may
have adverse effects on device operation.
The –3 dB frequency is set by RSEN (the parallel combination
of RSEN1 and RSEN2) at about 4.5 kΩ nominal; CMID is less well
controlled since RSEN1 and RSEN2 have been used to trim the rate
sensitivity during manufacturing and have a ±35% tolerance.
Its primary purpose is to limit the high frequency
demodulation artifacts from saturating the final amplifier stage.
Thus, this pole of nominally 400 Hz @ 0.1 µF need not be
Rev. C | Page 9 of 12
AD22304
precise. Lower frequency is preferable, but its variability usually requires it to be about 10 times greater (in order to preserve
phase integrity) than the well-controlled output pole. In general, both –3 dB filter frequencies should be set as low as possible to reduce the amplitude of these high frequency artifacts
as well as to reduce the overall system noise.
INCREASING MEASUREMENT RANGE
The full-scale measurement range of the AD22304 can be increased by placing an external resistor between the
RATEOUT (1B, 2A) and SUMJ (1C, 2C) pins, which would
parallel the internal ROUT resistor that is factory-trimmed to
180 kΩ. For example, a 330 kΩ external resistor will give
approximately 8.1 mV/°/sec sensitivity and a commensurate
~50% increase in the full-scale range. This is effective for up to
a 4× increase in the full-scale range (minimum value of the
parallel resistor allowed is 45 kΩ). Beyond this amount of external sensitivity reduction, the internal circuitry headroom
requirements prevent further increase in the linear full-scale
output range. The drawbacks of modifying the full-scale range
are the
additional output null drift (as much as 2°/sec over temperature) and the readjustment of the initial null bias (see the Null
Adjustment section).
TEMPERATURE OUTPUT AND CALIBRATION
It is common practice to temperature-calibrate gyros to
improve their overall accuracy. The AD22304 has a temperature-proportional voltage output that provides input to such a
calibration method. The voltage at TEMP (3F, 3G) is nominally
2.5 V at 27°C and has a PTAT (proportional to absolute temperature) characteristic of 8.4 mV/°C. Note that the TEMP
output circuitry is limited to 50 µA source current.
Using a 3-point calibration technique, it is possible to calibrate
the AD22304’s null and sensitivity drift to an overall accuracy
of nearly 300°/hour. An overall accuracy of 70°/hour or better
is possible using more points. Limiting the bandwidth of the
device reduces the flat-band noise during the calibration process,
improving the measurement accuracy at each calibration point.
USING THE AD22304 WITH A
SUPPLY-RATIOMETRIC ADC
The AD22304’s RATEOUT signal is nonratiometric, i.e., 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
AD22304 is used with a supply-ratiometric ADC, the
AD22304’s 2.5 V output can be converted and used to make
corrections in software for the supply variations.
NULL ADJUSTMENT
Null adjustment is possible by injecting a suitable current to
SUMJ (1C, 2C). Adding a suitable resistor to either ground or
the positive supply is a simple way of achieving this. The
nominal 2.5 V null is for a symmetrical swing range at RATEOUT (1B, 2A). However, a nonsymmetric output swing may be
suitable in some applications. Note that if a resistor is connected to the positive supply, supply disturbances may reflect
some null instability. Digital supply noise should be avoided
particularly in this case (see the Supply and Common Considerations section).
The resistor value to use is approximately
RNULL = ( 2.5 × 180 ,000 )/( VNULL0 – VNULL1 )
VNULL0 is the unadjusted zero-rate output, and VNULL1 is the target null value. If the initial value is below the desired value, the
resistor should terminate on common or ground. If it is above
the desired value, the resistor should terminate on the 5 V supply. Values typically are in the 1 MΩ to 5 MΩ range.
If an external resistor is used across RATEOUT and SUMJ, the
parallel equivalent value is substituted into the above equation.
Note that the resistor value is an estimate since it assumes VCC
= 5.0 V and VSUMJ = 2.5 V.
SELF-TEST FUNCTION
The AD22304 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 inputs ST1 (5F, 5G), ST2 (4F,
4G), or both. ST1 causes the voltage at RATEOUT to change
about
–0.66 V, and ST2 causes an opposite change of +0.66 V. The
self-test response follows the viscosity temperature dependence
of the package atmosphere, approximately 0.25%/°C.
Activating both ST1 and ST2 simultaneously is not damaging.
Since ST1 and ST2 are not necessarily closely matched, actuating both simultaneously may result in an apparent null bias
shift.
CONTINUOUS SELF-TEST
The one-chip integration of the AD22304 gives it higher reliability than is obtainable with any other high volume manufacturing method. Also, 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. Application notes outlining continuous self-test
techniques are also available on the Analog Devices website.
ACCELERATION SENSITIVITY
The sign convention used is that lateral acceleration is positive
in the direction from Pin Column A to Pin Column G of the
package. That is, a device has positive sensitivity if its voltage
output increases when the row of Pins 2A–6A are tipped under
the row of Pins 2G–6G in the earth’s gravity.
There are two effects of concern, shifts in the static null and
induced null noise. Scale factor is not significantly affected
until the acceleration reaches several hundred m/s2.
Vibration rectification for frequencies up to 20 kHz is on the
order of 0.00002(°/s)/(m/s2)2, is not significantly dependent on
frequency, and has been verified up to 400 m/s2 rms.
Rev. C | Page 10 of 12
AD22304
Linear vibration spectral density near the 14 kHz sensor resonance translates into output noise. In order to have a significant
effect, the vibration must be within the angular rate bandwidth
(typically ±40 Hz of the resonance), so it takes considerable
high frequency vibration to have any effect.
2.58
RATEOUT (V)
Away from the 14 kHz resonance the effect is not discernible,
except for vibration frequencies within the angular rate pass
band. This can be seen in Figure 10 to Figure 15 for the various
sensor axes. The in-band effect can be seen in Figure 25. This
is the result of the static g-sensitivity. The specimen used for
Figure 25 had a g-sensitivity of 0.15°/s/g and its total in-band
noise degraded from 3 mV rms to 5 mV rms for the specified
vibration. The effect of broadband vibration up to 20 kHz is
shown in Figure 24 and Figure 26.
2.60
STATIC 0.8mV rms
2.56
2.54
SHAKING 2.4mV rms
2.52
2.50
0
The output noise of the part falls away in accordance with the
output low-pass filter and does not contain any spikes greater
than 1% of the low frequency noise. A typical noise spectrum is
shown in Figure 27.
2
6
4
8
10
TIME (sec)
Figure 26. Random Vibration (Lateral) 10 kHz to 20 kHz
at 0.01 g/√Hz with 60 Hz Sampling and 0.5 sec Averaging
2.60
–60
–70
–80
2.56
RATEOUT (V)
RATEOUT (V)
2.58
2.54
2.52
–90
–100
–110
–120
2.50
0
2
6
4
8
10
–130
TIME (sec)
0
Figure 24. Random Vibration (Lateral) 10 kHz to 20 kHz
at 0.01 g/√Hz with 60 Hz Sampling and 0.5 sec Averaging
RATEOUT (V)
2.58
2.56
2.54
2.52
2.50
2
6
4
8
1000
100
FREQUENCY (Hz)
10000
100000
Figure 27. Noise Spectral Density at RATEOUT –BW = 4 Hz
2.60
0
10
10
TIME (sec)
Figure 25. Random Vibration (Lateral) 2 Hz to 40 Hz, 3.2 g rms
Rev. C | Page 11 of 12
AD22304
OUTLINE DIMENSIONS
A1 CORNER
INDEX AREA
7.00 BSC SQ
7
6
5
4
3
2
1
A
BALL A1
INDICATOR
B
C
BOTTOM
VIEW
TOP VIEW
D
E
F
G
4.80 BSC
DETAIL A
DETAIL A
3.20
2.50
0.44
0.25
3.65 MAX
0.15 MAX
COPLANARITY
0.60
SEATING
0.55
PLANE
0.50
BALL DIAMETER
0.80
BSC
Figure 28. 32-Lead Chip Scale Ball Grid Array [CSPBGA]
(BC-32)
Dimensions shown in millimeters
ORDERING GUIDE
Model
AD22304
Temperature Range
–40°C to +85°C
Package Description
32-Lead BGA
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C03226–0–3/04(B)
Rev. C | Page 12 of 12
Package Outline
BC-32