Datasheet ADXRS300 Datasheet (Analog Devices)

±300°/s Single Chip Yaw Rate

FEATURES

Complete rate gyroscope on a single chip
Z-axis (yaw rate) response
High vibration rejection over wide frequency
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)

APPLICATIONS

Vehicle chassis rollover sensing
Inertial measurement units
Platform stabilization

AVCC

ST1

ST2

5G

SELF
TEST

4G

3A

Gyro with Signal Conditioning

GENERAL DESCRIPTION

The ADXRS300 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 angular rate about the axis normal to the top surface of the
package (see Figure 4). 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 5).

A precision reference and a temperature output are also
provided for compensation techniques. Two digital self-test
inputs electromechanically excite the sensor to test proper
operation of both sensors and the signal conditioning circuits.
The ADXRS300 is available in a 7 mm × 7 mm × 3 mm BGA
chip-scale package.

FUNCTIONAL BLOCK DIAGRAM

–

+

5V

100nF 100nF

CMID

1D

R

SEN1

≈

7k

Ω

±

35%

RATE

SENSOR

AGND

2G 1F

CORIOLIS SIGNAL CHANNEL

π DEMOD

RESONATOR LOOP

ADXRS300

C

OUT

SUMJ

1C

R

OUT

R

≈

7k

Ω

SEN2

180k

Ω

1%

±

35%

1B

2A

RATEOUT

CHARGE PUMP/REG.

22nF

PDD

CP1

100nF

4A 5A 7E 6G

CP2

ADXRS300

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.

7F 6A 7D7C7B

PGND CP4

Figure 1.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2004 Analog Devices, Inc. All rights reserved.

12V

2.5V REF

CP3 CP5

22nF

PTAT

47nF

1E

2.5V

3G

TEMP

ADXRS300

TABLE OF CONTENTS

Specifications..................................................................................... 3

Increasing Measurement Range ..................................................7

Absolute Maximum Ratings............................................................ 4

Rate Sensitive Axis........................................................................ 4

ESD Caution.................................................................................. 4

Pin Configuration and Function Descriptions............................. 5

Theory of Operation ........................................................................ 6

Supply and Common Considerations ....................................... 6

Setting Bandwidth ........................................................................ 7

REVISION HISTORY

3/04—Data Sheet Changed from Rev. A to Rev. B

Updated Format..................................................................Universal

Changes to Table 1 Conditions....................................................... 3

Added Evaluation Board to Ordering Guide................................ 8

3/03—Data Sheet Changed from Rev. 0 to Rev. A

Edit to Figure 3.................................................................................. 5

Using the ADXRS300 with a Supply-Ratiometric ADC ..........7

Null Adjust .....................................................................................7

Self-Test Function .........................................................................7

Continuous Self-Test.....................................................................7

Outline Dimensions..........................................................................8

Ordering Guide .............................................................................8

Rev. B | Page 2 of 8

ADXRS300

SPECIFICATIONS

@TA = 25°C, VS = 5 V, Angular Rate = 0°/s, Bandwidth = 80 Hz (C

Table 1.

Parameter Conditions

SENSITIVITY Clockwise rotation is positive output

Dynamic Range2 Full-scale range over specifications range ±300 °/s
Initial @25°C 4.6 5 5.4 mV/°/s
Over Temperature3 V

= 4.75 V to 5.25 V 4.6 5 5.4 mV/°/s

S

Nonlinearity Best fit straight line 0.1 % of FS

NULL

Initial Null 2.3 2.50 2.7 V
Over Temperature3 V

= 4.75 V to 5.25 V 2.3 2.7 V

S

Turn-On Time Power on to ±½°/s of final 35 ms
Linear Acceleration Effect Any axis 0.2 °/s/g
Voltage Sensitivity VCC = 4.75 V to 5.25 V 1 °/s/V

NOISE PERFORMANCE

Rate Noise Density @25°C 0.1

FREQUENCY RESPONSE

3 dB Bandwidth (User Selectable)4 22 nF as comp cap (see the Setting Bandwidth section) 40 Hz
Sensor Resonant Frequency 14 kHz

SELF-TEST INPUTS

ST1 RATEOUT Response5 ST1 pin from Logic 0 to 1 –150 –270 –450 mV
ST2 RATEOUT Response5 ST2 pin from Logic 0 to 1 +150 +270 +450 mV
Logic 1 Input Voltage Standard high logic level definition 3.3 V
Logic 0 Input Voltage Standard low logic level definition 1.7 V
Input Impedance To common 50 kΩ

TEMPERATURE SENSOR

V

at 298°K 2.50 V

OUT

Max Current Load on Pin Source to common 50 µA
Scale Factor Proportional to absolute temperature 8.4 mV/°K

OUTPUT DRIVE CAPABILITY

Output Voltage Swing I

= ±100 µA 0.25 VS – 0.25 V

OUT

Capacitive Load Drive 1000 pF

2.5 V REFERENCE
Voltage Value 2.45 2.5 2.55 V
Load Drive to Ground Source 200 µA
Load Regulation 0 < I

< 200 µA 5.0 mV/mA

OUT

Power Supply Rejection 4.75 VS to 5.25 VS 1.0 mV/V
Temperature Drift Delta from 25°C 5.0 mV

POWER SUPPLY

Operating Voltage Range 4.75 5.00 5.25 V
Quiescent Supply Current 6.0 8.0 mA

TEMPERATURE RANGE

Specified Performance Grade A Temperature tested to max and min specifications –40 +85 °C

= 0.01 µF), ±1g, unless otherwise noted.

OUT

Min

ADXRS300ABG

1

Typ Max1

Unit

°/s/√Hz

1

All minimum and maximum specifications are guaranteed. Typical specifications are not tested or guaranteed.

2

Dynamic range is the maximum full-scale measurement range possible, including output swing range, initial offset, sensitivity, offset drift, and sensitivity drift at

5 V supplies.

3

Specification refers to the maximum extent of this parameter as a worst-case value of T

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.

Rev. B | Page 3 of 8

or T

MAX

.

MIN

ADXRS300

V

ABSOLUTE MAXIMUM RATINGS

Table 2.

Parameter Rating

Acceleration (Any Axis, Unpowered, 0.5 ms) 2000 g
Acceleration (Any Axis, Powered, 0.5 ms) 2000 g
+VS –0.3 V to +6.0 V
Output Short-Circuit Duration

Indefininte

(Any Pin to Common)
Operating Temperature Range –55°C to +125°C
Storage Temperature –65°C to +150°C

Stresses above those listed under the 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.

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.

RATE SENSITIVE AXIS

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.

LONGITUDINAL

AXIS

ABCDEFG

A1

LATERAL AXIS

Figure 2. RATEOUT Signal Increases with Clockwise Rotation

RATE

AXIS

1

VCC= 5V

7

GND

RATEOUT

4.75V

2.5V
RATE IN

0.25

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. B | Page 4 of 8

ADXRS300

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

PGND

ST1

ST2

TEMP

AGND

PDD

2.5V

GFEDCBA

CP5

CMID

CP3

SUMJ

CP4

CP1

CP2

AVCC

RATEOUT

Figure 3. 32-Lead BGA (Bottom View)

Table 3. Pin Function Descriptions

Pin No. Mnemonic Description

6D, 7D CP5 HV Filter Capacitor—47 nF
6A, 7B CP4
6C, 7C CP3
5A, 5B CP1
4A, 4B CP2

Charge Pump Capacitor—22 nF
Charge Pump Capacitor—22 nF
Charge Pump Capacitor—22 nF

Charge Pump Capacitor—22 nF
3A, 3B AVCC + Analog Supply
1B, 2A RATEOUT Rate Signal Output
1C, 2C SUMJ Output Amp Summing Junction
1D, 2D CMID HF Filter Capacitor—100 nF
1E, 2E 2.5V 2.5 V Precision Reference
1F, 2G AGND Analog Supply Return
3F, 3G TEMP Temperature Voltage Output
4F, 4G ST2 Self-Test for Sensor 2
5F, 5G ST1 Self-Test for Sensor 1
6G, 7F PGND Charge Pump Supply Return
6E, 7E PDD + Charge Pump Supply

7

6

5

4

3

2

1

Rev. B | Page 5 of 8

ADXRS300

–

THEORY OF OPERATION

The ADXRS300 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, 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.

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

100nF

PDD

) and an

SEN1

PGND

7F

6G

5G

4G

3G

2G

ST1

ST2

TEMP

filter consisting of an internal 7 kΩ resistor (R
external user-supplied capacitor (CMID). A CMID capacitor of
100 nF sets a 400 Hz ±3 5% low-pass pole and is used to limit
high frequency artifacts before final amplification. The band­width limit capacitor, C

, sets the pass bandwidth (see Figure 5

OUT

and the Setting Bandwidth section).

22nF

CP4

7B

6A

CP1

22nF

CP2

5V

AVCC

5A

4A

3A

2A

CP5

CP3

7C

7D 7E

47nF

100nF

SUPPLY AND COMMON CONSIDERATIONS

Only power supplies used for supplying analog circuits are
recommended for powering the ADXRS300. High frequency
noise and transients associated with digital circuit supplies may
have adverse effects on device operation.

Figure 4 shows the recommended connections for the ADXRS300
where both AVCC and PDD have a separate decoupling capacitor.
These should be placed as close to the their respective pins as
possible before routing to the system analog supply. This mini­mizes 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.

+

5V

SEN2

SUMJ

1C

R

180kΩ 1%

47nF

C

OUT

OUT

1B

RATE­OUT

2A

2.5V

1E

TEMP

3G

5G

ST1

SELF
TEST

ST2

4G

ADXRS300

100nF

AGND

CORIOLIS

CMID

1F

R

SEN1

π

DEMOD

PGND

≈7kΩ±35%

12V

7F 6A 7B7C7D

CP4

1D

R

2.5V REF
PTAT

CP3 CP5

22nF

AVCC

3A

CP2

100nF

RATE

SENSOR

4A

5A

22nF

CP1

2G

SIGNAL CHANNEL

RESONATOR LOOP

CHARGE

PUMP/REG.

PDD

7E

6G

100nF

Figure 5. Block Diagram with External Components

1D

1C

1B

RATEOUT

NOTE THAT INNER ROWS/COLUMNS OF PINS HAVE BEEN OMITTED
FOR CLARITY BUT SHOULD BE CONNECTED IN THE APPLICATION.

SUMJ

= 22nF

C

OUT

CMID

100nF

1E

2.5V

1F

AGND

Figure 4. Example Application Circuit (Top View)

Rev. B | Page 6 of 8

ADXRS300

×

=

SETTING BANDWIDTH

External capacitors CMID and C
with on-chip resistors to create two low-pass filters to limit the
bandwidth of the ADXRS300’s rate response. The –3 dB
frequency set by R

OUT

and C

OUT

()

and can be well controlled since R
manufacturing to be 180 kΩ ± 1%. Any external resistor applied
between the RATEOUT (1B, 2A) and SUMJ (1C, 2C) pins
results in

()()

The –3 dB frequency is set by RSEN (the parallel combination
of R

and R

SEN1

controlled since R
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 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 and to reduce the
overall system noise.

) at about 3.5 kΩ nominal; CMID is less well

SEN2

and R

SEN1

SEN2

are used in combination

OUT

is

CR/f ×××= π21

OUTOUTOUT

has been trimmed during

OUT

R/RR ××= kΩ180kΩ180

EXTEXTOUT

have been used to trim the rate

INCREASING MEASUREMENT RANGE

The full-scale measurement range of the ADXRS300 can be
increased by placing an external resistor between the RATEOUT
(1B, 2A) and SUMJ (1C, 2C) pins, which would parallel the
internal R

resistor that is factory-trimmed to 180 kΩ. For

OUT

example, a 330 kΩ external resistor will give ~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 Adjust
section).

USING THE ADXRS300 WITH A SUPPLY­RATIOMETRIC ADC

The ADXRS300’s RATEOUT signal is nonratiometric, i.e.,
neither the null voltage nor the rate sensitivity is proportional to
the supply. Rather they are nominally constant for dc supply
changes within the 4.75 V to 5.25 V operating range. If the
ADXRS300 is used with a supply-ratiometric ADC, the
ADXRS300’s 2.5 V output can be converted and used to make
corrections in software for the supply variations.

NULL ADJUST

Null adjustment is possible by injecting a suitable current to
SUMJ (1C, 2C). Adding a suitable resistor to either ground or to
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, then supply disturbances may
reflect some null instabilities. Digital supply noise should be
avoided, particularly in this case (see the Supply and Common
Considerations section).

The resistor value to use is approximately

)()00018052(

is the unadjusted zero rate output, and V

V

NULL0

V– V/, . R

NULL1NULL0NULL

is the target

NULL1

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 are typically in the 1 MΩ to 5 MΩ range.

If an external resistor is used across RATEOUT and SUMJ, then
the parallel equivalent value is substituted into the preceding
equation. Note that the resistor value is an estimate since it
assumes V

= 5.0 V and V

CC

SUMJ

= 2.5 V.

SELF-TEST FUNCTION

The ADXRS300 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 a voltage at RATEOUT equivalent to typically
–270 mV, and ST2 causes an opposite +270 mV change. 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 ADXRS300 gives it higher
reliability than is obtainable with any other high volume
manufac turing method. Also, it is manufac tured 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 self­test techniques are also available on the Analog Devices website.

Rev. B | Page 7 of 8

ADXRS300

OUTLINE DIMENSIONS

3.20

2.50

3.65 MAX

7.00 BSC SQ

BALL A1
INDICATOR

TOP VIEW

DETAIL A

0.80

BSC

76543

0.44

0.25

BALL DIAMETER

Figure 6. 32-Lead Chip Scale Ball Grid Array [CSPBGA]

(BC-32)

Dimensions shown in millimeters

INDEX AREA

T

O

T

B

O

VIEW

4.80 BSC

DETAIL A

0.60

0.55

0.50

A1 CORNER

21

M

SEATING
PLANE

A
B
C
D
E
F
G

0.15 MAX
COPLANARITY

ORDERING GUIDE

Model Temperature Range Package Description Package Outline

ADXRS300ABG –40°C to +85°C 32-Lead BGA BC-32
ADXRS300ABG-Reel –40°C to +85°C 32-Lead BGA BC-32
ADXRS300EB Evaluation Board

© 2004 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.

C03227–0–3/04(B)

Rev. B | Page 8 of 8