AD ADIS16350 Tri-axis inertial sensor Datasheet

Tri-Axis Inertial Sensor
ADIS16355
FEATURES
AUX_ADC
AUX_DAC
TEMPERATURE
SENSORS
TRI-AXIS MEMS
ANGULAR RATE SENSOR
SIGNAL
CONDITIONING
AND
CONVERSION
CALIBRATION
AND
DIGITAL
PROCESSING
CS
SCLK
SPI
PORT
DIGITAL
CONTROL
SELF-TEST
DIN
DOUT
VCC
TRI-AXIS MEMS
ACCELLERATION
SENSOR
GND
POWER
MANAGEMENT
ALARMS
RST
AUX
I/O
DIO1 DIO2
06522-001
Tri-axis gyroscope with digital range scaling
±75, ±150, ±300°/s settings
14-bit resolution
Tri-axis accelerometer
±10 g measurement range
14-bit resolution
350 Hz bandwidth
Factory calibrated sensitivity, bias, and alignment
ADIS16350: +25°C, ADIS16355: -40°C to +85°C
Digitally controlled bias calibration
Digitally controlled sample rate
Digitally controlled filtering
Programmable condition monitoring
Auxiliary digital input/output
Digitally activated self-test
Programmable power management
Embedded temperature sensor
SPI-compatible serial interface
Auxiliary 12-bit ADC input and DAC output
Single-supply operation: 4.75 V to 5.25 V
2000 g shock survivability
Figure 1.
APPLICATIONS
Guidance and control
Platform control and stabilization
Motion control and analysis
Inertial measurement units
General navigation
Image stabilization
RoboticsFunctional Block Diagram
GENERAL DESCRIPTION
The ADIS16350/5 iSensorTM is a complete triple axis gyroscope
and triple axis accelerometer inertial sensing system. This
sensor combines the Analog Devices Inc. iMEMS® and mixed
signal processing technology to produce a highly integrated
solution, providing calibrated, digital inertial sensing. An SPI
interface and simple output register structure allow for easy
system interface and programming. The ADIS16355 provides
calibration over a temperature range of -40°C to +85°C.
The SPI port provides access to the following embedded
sensors: X, Y, and Z axis angular rates; X, Y, and Z axis linear
acceleration; internal temperature; power supply; and auxiliary
analog input. The inertial sensors are precision aligned across
axes, and are calibrated for offset and sensitivity. An embedded
controller dynamically compensates for all major influences on
the MEMS sensors; thus maintaining highly accurate sensor
outputs without further testing, circuitry, or user intervention.
System integration is simplified with the following additional
programmable features:
• In-system auto bias calibration
• Digital filtering and sample rate
• Self test
• Power management
• Condition monitoring
• Auxiliary digital input/output
This compact module is approximately 23 mm × 23 mm ×
23 mm and provides a convenient flex-based connector system.
Rev. PrG
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
©2007 Analog Devices, Inc. All rights reserved.
ADIS16355
TABLE OF CONTENTS
Features .............................................................................................. 1
Control Register Structure ........................................................ 12
Applications....................................................................................... 1
Auxiliary ADC Function........................................................... 12
Functional Block Diagram .............................................................. 1
Basic Operation .............................................................................. 13
General Description ......................................................................... 1
Serial Peripheral Interface (SPI)............................................... 13
Revision History ............................................................................... 2
Data Output Register Access .................................................... 14
Specifications..................................................................................... 3
Programming and Control............................................................ 16
Timing Specifications .................................................................. 5
Control Register Overview ....................................................... 16
Timing Diagrams.......................................................................... 5
Control Register Structure ........................................................ 16
Absolute Maximum Ratings............................................................ 6
Calibration................................................................................... 17
ESD Caution.................................................................................. 6
Global Commands ..................................................................... 17
Pin Configuration and Function Descriptions............................. 7
Operational Control................................................................... 18
Typical Performance Characteristics ............................................. 8
Status and Diagnostics............................................................... 20
Theory of Operation ...................................................................... 12
Applications Information .............................................................. 23
Overview...................................................................................... 12
Installation Guidelines............................................................... 23
Gyroscope Sensor....................................................................... 12
Outline Dimensions ....................................................................... 25
Accelerometer Sensor ................................................................ 12
Ordering Guide .......................................................................... 25
Factory Calibration .................................................................... 12
REVISION HISTORY
10/31—Revision PrG: Document performance, pending release
Rev. PrG | Page 2 of 28
ADIS16355
SPECIFICATIONS
Table 1. TA = −40°C to +85°C, VCC = 5.0 V, angular rate = 0°/s, dynamic range 300°/sec, ±1 g, unless otherwise noted
Parameter
GYROSCOPE SENSITIVITY
Initial
Temperature Coefficient
Gyro Axis Nonorthogonality
Gyro Axis Misalignment
Nonlinearity
GYROSCOPE BIAS
In Run Bias Stability
Angular Random Walk
Temperature Coefficient
Linear Acceleration Effect
Voltage Sensitivity
GYROSCOPE NOISE PERFORMANCE
Output Noise
Rate Noise Density
GYROSCOPE FREQUENCY RESPONSE
3 dB Bandwidth
Sensor Resonant Frequency
GYROSCOPE SELF-TEST STATE
Change for Positive Stimulus
Change for Negative Stimulus
Internal Self-Test Cycle Time
ACCELEROMETER SENSITIVITY
Dynamic Range
Initial
Temperature Coefficient
Axis Nonorthogonality
Axis Misalignment
Nonlinearity
ACCELEROMETER BIAS
In-Run Bias Stability
Velocity Random Walk
Temperature Coefficient
ACCELEROMETER NOISE PERFORMANCE
Output Noise
Noise Density
ACCELEROMETER FREQUENCY RESPONSE
3 dB Bandwidth
Sensor Resonant Frequency
ACCELEROMETER SELF-TEST STATE
Output Change When Active
Conditions
Each axis
25°C, dynamic range = ±300°/s
25°C, dynamic range = ±150°/s
25°C, dynamic range = ±75°/s
ADIS16350, See Figure 5
ADIS16355, See TBD
25°C, difference from 90° ideal
25°C, relative to base -plate and guide pins
Best fit straight line
Min
Typ
Max
0.0725
0.07326
0.03663
0.01832
600
40
±0.05
±0.5
0.1
0.0740
Unit
°/s/LSB
°/s/LSB
°/s/LSB
ppm/°C
ppm/°C
Degree
Degree
% of FS
25°C, 1 σ
25°C
ADIS16350, See Figure 6
ADIS16355, See
Any axis, 1 σ, (linear acceleration bias
compensation enabled)
VCC = 4.75 V to 5.25 V
0.015
4.2
0.1
0.01
0.05
°/s
°/√hr
°/s/°C
°/s/°C
°/s/g
0.25
°/s/V
25°C, ±300°/s range, no filtering
25°C, ±150°/s range, 4-tap filter setting
25°C, ±75°/s range, 16-tap filter setting
25°C, f = 25 Hz, ±300°/s, no filtering
0.60
0.35
0.17
0.05
°/s rms
°/s rms
°/s rms
°/s/√Hz rms
350
14
Hz
kHz
±300°/s range setting
±300°/s range setting
432
−432
723
−723
25
±8
2.471
±10
2.522
100
40
±0.25
±0.5
±0.2
1105
−1105
LSB
LSB
ms
Each axis
25°C
ADIS16350
ADIS16355
25°C, difference from 90° ideal
25°C, relative to base-plate and guide pins
Best fit straight line
2.572
g
mg/LSB
ppm/°C
ppm/°C
Degree
Degree
% of FS
25°C, 1 σ
25°C
ADIS16350
ADIS16355
0.7
2.0
4
0.5
mg
m/s/√hr
mg/°C
mg/°C
25°C, no filtering
25°C, no filtering
35
1.85
mg rms
mg/√Hz rms
350
10
Hz
kHz
73
Rev. PrG | Page 3 of 28
146
219
LSB
ADIS16355
Parameter
TEMPERATURE SENSOR
Output at 25°C
Scale Factor
ADC INPUT
Resolution
Integral Nonlinearity
Differential Nonlinearity
Offset Error
Gain Error
Input Range
Input Capacitance
DAC OUTPUT
Resolution
Relative Accuracy
Differential Nonlinearity
Offset Error
Gain Error
Output Range
Output Impedance
Output Settling Time
LOGIC INPUTS
Input High Voltage, VINH
Input Low Voltage, VINL
Logic 1 Input Current, IINH
Logic 0 Input Current, IINL
All except RST
RST
Input Capacitance, CIN
DIGITAL OUTPUTS
Output High Voltage, VOH
Output Low Voltage, VOL
SLEEP TIMER
Timeout Period1
FLASH MEMORY
Endurance2
Data Retention3
CONVERSION RATE
Maximum Sample Rate
Minimum Sample Rate
START-UP TIME4
Initial Power Up
Sleep Mode Recovery
POWER SUPPLY
Operating Voltage Range, VCC
Power Supply Current
Conditions
Min
Typ
Max
0
6.88
LSB
LSB/°C
12
±2
±1
±4
±2
20
Bits
LSB
LSB
LSB
LSB
V
pF
12
±4
±1
±5
±0.5
0 to 2.5
2
10
Bits
LSB
LSB
mV
%
V
Ω
μs
0
During acquisition
5 kΩ/100 pF to GND
For Code 101 to Code 4095
2.5
2.0
For −CS signal when used to wake up from
sleep mode
VIH = 3.3 V
VIL = 0 V
ISOURCE = 1.6 mA
ISINK = 1.6 mA
0.8
V
V
0.55
V
±0.2
±10
μA
−40
−1
10
−60
μA
mA
pF
2.4
0.5
0.4
V
V
128
Sec
10,000
20
TJ = 85C
SMPL_PRD = 0x01
SPML_PRD = 0xFF
4.75
Normal mode at 25°C
Fast mode at 25°C
Sleep mode at 25°C
1
Unit
Cycles
Years
819.2
0.413
SPS
SPS
150
3
ms
ms
5.0
33
57
500
5.25
V
mA
mA
μA
Guaranteed by design
Endurance is qualified as per JEDEC Standard 22 Method A117 and measured at −40°C, +25°C, +85°C, and +125°C.
Retention lifetime equivalent at junction temperature (TJ) 85°C as per JEDEC Standard 22 Method A117. Retention lifetime decreases with junction temperature.
4
This is defined as the time from wake-up to the first conversion. This time does not include sensor settling time, which is dependent on the filter settings
2
3
Rev. PrG | Page 4 of 28
ADIS16355
TIMING SPECIFICATIONS
TA = 25°C, Vcc = 5.0 V, angular rate = 0°/s, unless otherwise noted.
Table 2.
Parameter
fSCLK
Min1
0.01
10
40
160
9
75
48.8
Description
Fast mode, SMPL_PRD ≤ 0x09 (fS ≥ 164 Hz)
Normal mode, SMPL_PRD ≥ 0x0A (fS ≤ 149 Hz)
Data rate time, fast mode, SMPL_PRD ≤ 0x09 (fS ≥ 164 Hz)
Data rate time, normal mode, SMPL_PRD ≥ 0x0A (fS ≤ 149 Hz)
Data stall time, fast mode SMPL_PRD ≤ 0x09 (fS ≥ 164 Hz)
Data stall time, normal mode SMPL_PRD ≥ 0x0A (fS ≤ 149 Hz)
Chip select to clock edge
Data output valid after SCLK falling edge2
Data input setup time before SCLK rising edge
Data input hold time after SCLK rising edge
Data output fall time
Data output rise time
CS high after SCLK edge3
tDATARATE
tDATASTALL
tCS
tDAV
tDSU
tDHD
tDF
tDR
tSFS
Typ
Max1
2
300
100
24.4
48.8
5
5
12.5
12.5
5
1
Unit
MHz
kHz
μs
μs
μs
μs
ns
ns
ns
ns
ns
ns
ns
Guaranteed by design, not production tested.
The MSB presents an exception to this parameter. The MSB clocks out on the falling edge of CS. The rest of the DOUT bits are clocked after the falling edge of SCLK and
are governed by this specification.
3
This parameter may need to be expanded to allow for proper capture of the LSB. After CS goes high, the DOUT line goes into a high impedance state.
2
TIMING DIAGRAMS
tDATARATE
CS
06522-002
SCLK
tDATASTALL
Figure 2. SPI Chip Select Timing
CS
tCS
SCLK
tSFS
1
2
3
4
5
6
15
16
tDAV
MSB
DB14
DB13
tDSU
DIN
W/R
DB12
DB11
A4
A3
DB10
DB2
DB1
LSB
tDHD
A5
A2
D2
D1
Figure 3. SPI Timing, Utilizing SPI Settings Typically Identified as Phase = 1, Polarity = 1
Rev. PrG | Page 5 of 28
LSB
06522-003
DOUT
ADIS16355
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
Acceleration
Any Axis, Unpowered
Any Axis, Powered
VCC to COM
Digital Input/Output Voltage to COM
Analog Inputs to COM
Operating Temperature Range
Storage Temperature Range
Rating
2000 g
2000 g
−0.3 V to +6.0 V
−0.3 V to +5.3 V
−0.3 V to 3.6 V
−40°C to +85°C
−65°C to +125°C1, 2
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.
Table 4. Package Characteristics
Package Type
24-Lead Module
1
Extended exposure to temperatures outside of the specified temperature
range of −40°C to +85°C can adversely affect the accuracy of the factory
calibration. For best accuracy, store the parts within the specified operating
range of −40°C to +85°C.
2
Although the device is capable of withstanding short-term exposure to
+150°C, long-term exposure threatens internal mechanical integrity.
ESD CAUTION
Rev. PrG | Page 6 of 28
θJA
39.8°C/W
θJC
14.2°C/W
Device Weight
16 grams
ADIS16355
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
PIN 1
PIN 23
TOP VIEW
Z
X
Y
PIN 24
FLEX
TO HOUSING
2
23
1
Figure 4. Pin Configuration, Connector Top View
Table 5. 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
1
Mnemonic
DNC
DNC
SCLK
DOUT
DIN
CS
DIO1
RST
DIO2
VCC
VCC
VCC
GND
GND
GND
DNC
DNC
DNC
DNC
AUX_DAC
AUX_ADC
DNC
DNC
DNC
Type1
N/A
N/A
I
O
I
I
I/O
I
I/O
S
S
S
S
S
S
N/A
N/A
N/A
N/A
O
I
N/A
N/A
N/A
Description
Do not connect
Do not connect
SPI serial clock
SPI data output
SPI data input
SPI chip select
Digital input/output
Reset
Digital input/output
Power supply
Power supply
Power supply
Power ground
Power ground
Power ground
Do not connect
Do not connect
Do not connect
Do not connect
Auxiliary, 12-bit, DAC output
Auxiliary, 12-bit, ADC input
Do not connect
Do not connect
Do not connect
S = supply, O = output, I = input.
Rev. PrG | Page 7 of 28
POINT OF PERCUSSION
(WHEN LINEAR ACCELEROMETER
ORIGIN ALIGNMENT ENABLED)
06522-004
PIN 2
ADIS16355
TYPICAL PERFORMANCE CHARACTERISTICS
5
4
3
0.40
+1σ
0.30
µ
0.20
Sensitivity - %
1
0
–1σ
–1
+1 σ
0.10
μ
0.00
-1 σ
-0.10
–2
-0.20
–3
-0.30
–4
-0.40
-50
–5
–50
06522-030
SENSITIVITY (%)
2
–35
–20
–5
10
25
40
55
70
85
-35
-20
-5
10
25
40
55
70
85
100
TEMPERATURE (oC)
100
Gyroscope Sensitivity vs. Temperature
TEMPERATURE (°C)
Figure 8. ADIS16355 Gyroscope Sensitivity vs. Temperature
Figure 5. ADIS16350 Gyroscope Sensitivity vs. Temperature
20
15
1.00
10
0.75
+1σ
0.50
BIAS (deg/sec)
BIAS (°/s)
5
µ
0
–5
–1σ
+1 σ
0.25
μ
0.00
-1 σ
-0.25
-0.50
-0.75
–15
-1.00
-50
–20
–50
06522-031
–10
–35
–20
–5
10
25
40
55
70
85
-35
-20
-5
10
25
40
55
70
85
100
85
100
TEMPERATURE (oC)
100
Gyroscope Bias vs. Temperature
TEMPERATURE (°C)
Figure 6. ADIS16350 Gyroscope Bias vs. Temperature
Figure 9. ADIS16350 Gyroscope Bias vs. Temperature
1.0
0.8
0.6
1.00
+1σ
0.75
µ
0.50
Sensitivity (%)
0.2
0
–1σ
–0.2
–0.4
+1 σ
0.00
μ
-0.25
-1 σ
-0.75
–0.6
–0.8
–1.0
–50
0.25
-0.50
06522-032
SENSITIVITY (%)
0.4
–35
–20
–5
10
25
40
55
70
85
100
-1.00
-50
-35
-20
-5
10
25
40
55
70
TEMPERATURE (oC)
Accelerometer Sensitivity vs. Temperature
TEMPERATURE (°C)
Figure 7. ADIS16350 Accelerometer Sensitivity vs. Temperature
Figure 10. ADIS16350 Accelerometer Sensitivity vs. Temperature
Rev. PrG | Page 8 of 28
ADIS16355
400
300
60
200
40
+1 σ
+1σ
BIAS (mg)
BIAS (mg)
100
0
µ
–100
μ
0
-1 σ
-20
-40
–200
–1σ
-60
-50
06522-033
–300
–400
–50
20
–35
–20
–5
10
25
40
55
70
85
-35
-20
-5
10
25
40
55
70
85
100
TEMPERATURE (oC)
100
Accelerometer Bias vs. Temperature
TEMPERATURE (°C)
Figure 11. ADIS16350 Accelerometer Bias vs. Temperature
Figure 14. ADIS16350 Accelerometer Bias vs. Temperature
45
40
PERCENTAGE OF POPULATION (%)
0.1
+1σ
MEAN
0.01
35
30
25
20
15
10
5
–1σ
0
–0.1
0
0.1
0.2
0.3
0.4
SENSITIVITY ERROR (%)
0.1
1
10
100
1000
INTEGRATION TIME (Seconds)
06522-005
0.001
0.01
06522-010
ROOT ALLAN VARIANCE (°/s)
1
Figure 15. Gyroscope Sensitivity Error, +25°C
Figure 12. Gyroscope Root Allan Variance
35
+1σ
0.001
MEAN
–1σ
0.0001
0.01
0.1
1
10
100
1000
30
25
20
15
10
5
0
–0.3
–0.2
–0.1
0
0.1
0.2
BIAS VOLTAGE SENSITIVITY (°/s/V)
0.3
0.4
06522-011
PERCENTAGE OF POPULATION (%)
0.01
06522-008
ROOT ALLAN VARIANCE (g)
0.1
Figure 16. Gyroscope Bias Voltage Power Supply Sensitivity, +25°C
INTEGRATION TIME (Seconds)
Figure 13. Accelerometer Root Allan Variance
Rev. PrG | Page 9 of 28
ADIS16355
14.05
35
SENSITIVITY (°/s/LSB)
13.85
25
20
15
+1σ
13.75
MEAN
13.65
13.55
–1σ
13.45
10
0
–0.5 –0.4 –0.3 –0.2 –0.1
0
0.1
0.3
0.3
0.4
0.5
SENSITIVITY ERROR (%)
13.25
–360
–270
–180
–90
0
90
180
270
06522-006
13.35
5
06522-013
PERCENTAGE OF POPULATION (%)
13.95
30
360
RATE (°/s)
Figure 20. Gyroscope Linearity
Figure 17. Accelerometer Sensitivity Error Distribution, +25°C
0.5
20
0.4
0.3
16
0.2
14
BIAS (°/s)
12
10
8
0.1
0
–0.1
–0.2
6
–0.3
4
20:19
06522-017
19:27
18:35
17:44
16:52
16:00
15:09
14:17
13:25
12:33
11:42
9:58
10:50
9:06
8:15
7:07
6:02
5:10
4:19
TIME (Hour:Minute)
Figure 21. Long-Term Bias Stability, +25°C
Figure 18. Gyroscope Bias Sensitivity to Linear Acceleration, +25°C
25
30
25
20
15
10
5
15
10
5
0
0
0.02 0.04 0.06 0.08 0.10
GYROSCOPE AXIS NONORTHOGANALITY (°)
–0.24
06522-015
0
–0.10 –0.08 –0.06 –0.04 –0.02
20
–0.16
–0.08
0
0.08
0.16
0.24
ACCELEROMETER AXIS NONORTHOGANALITY (°)
06522-018
PERCENTAGE OF POPULATION (%)
35
PERCENTAGE OF POPULATION (%)
3:27
0.02 0.04 0.06 0.08 0.10
2:35
0
(°/s/g)
1:43
–0.5
06522-014
0
–0.10 –0.08 –0.06 –0.04 –0.02
0.00
–0.4
2
0:51
PERCENTAGE OF POPULATION (%)
18
Figure 22. Accelerometer Alignment Distribution, +25°C
Figure 19. Gyroscope Alignment Distribution, +25°C
Figure 23. Normal Mode Power Supply Current Distribution, +25°C
Rev. PrG | Page 10 of 28
ADIS16355
35
20
15
10
5
30
25
20
15
10
5
0
0
45
46
47
48
49
50
51
52
53
54
55
56
57
58
GYROSCOPE POSITIVE SELF-TEST (°/s)
0.30
0.32
0.34
0.36
0.38
0.40
0.42
0.44
0.46
0.48
ACCELEROMETER SELF-TEST (g)
Figure 24. Gyroscope Positive Self-Test Distribution, +25°C
06522-022
PERCENTAGE OF POPULATION (%)
25
06522-020
PERCENTAGE OF POPULATION (%)
30
Figure 26. Accelerometer Self-Test Distribution, +25°C
2.722
SENSITIVITY (mg/LSB)
2.622
20
15
10
+1σ
MEAN
2.522
–1σ
2.422
2.322
–16
0
–57 –56 –55 –54 –53 –52 –51 –50 –49 –48 –47 –46 –45 –44
GYROSCOPE NEGATIVE SELF-TEST (°/s)
Figure 25 Gyroscope Negative Self-Test Distribution, +25°C
Rev. PrG | Page 11 of 28
–12
–8
–4
0
4
8
ACCELERATION (g)
Figure 27. Accelerometer Linearity
12
16
06522-009
5
06522-021
PERCENTAGE OF POPULATION (%)
25
ADIS16355
THEORY OF OPERATION
OVERVIEW
CONTROL REGISTER STRUCTURE
The ADIS16350 integrates three orthogonal axes of gyroscope
sensors with three orthogonal axes of accelerometer sensors,
creating the basic six degrees of freedom (6DOF) in a single
package. The accelerometers are oriented along the axis of rotation for each gyroscope. These six sensing elements are held
together by a mechanical structure that provides tight force and
motion coupling. Each sensor’s output signal is sampled using
an ADC, and then the digital data is fed into a proprietary digital
processing circuit. The digital processing circuit applies the
correction tables to each sensor’s output, manages the input/
output function using a simple register structure and serial interface, and provides many other features that simplify system-level
designs.
The ADIS16350 provides configuration control to many critical
operating parameters by using a dual-memory register structure.
The volatile SRAM register locations control operation of the
part while the nonvolatile flash memory locations preserve the
configuration settings. Updating a register’s contents only
affects its SRAM location. Preserving the updates in its corresponding flash memory location requires initiation of the flash
update command. This helps reduce the number of write cycles
to the flash memory and consequently increases the endurance
of the flash memory. During startup and reset-recovery sequences, the flash memory contents are automatically loaded into
the SRAM register locations.
GYROSCOPE SENSOR
The auxiliary ADC function integrates a standard 12-bit ADC
into the ADIS16350 to digitize other system-level analog
signals. The output of the ADC can be monitored through the
AUX_ADC register, as defined in Table 7. The ADC is a 12-bit
successive approximation converter. The output data is presented in straight binary format with the full-scale range
extending from 0 V to 2.5 V.
ACCELEROMETER SENSOR
The core acceleration sensor used in the ADIS16350 is a surface
micromachined polysilicon structure built on top of the silicon
wafer. Polysilicon springs suspend the structure over the surface
of the wafer and provide a resistance against acceleration forces.
Deflection of the structure is measured using a differential capacitor that consists of independent fixed plates and central
plates attached to the moving mass. Acceleration deflects the
beam and unbalances the differential capacitor, resulting in a
differential output that is fed to a series of gain and demodulation stages that produce the electrical rate signal output.
Figure 28 shows the equivalent circuit of the analog input
structure of the ADC. The input capacitor (C1) is typically 4 pF
and can be attributed to parasitic package capacitance. The two
diodes provide ESD protection for the analog input. Care must
be taken to ensure that the analog input signals are never
outside the range of −0.3 V to +3.5 V. This causes the diodes
to become forward-biased and to start conducting. The diodes
can handle 10 mA without causing irreversible damage. The
resistor is a lumped component that represents the on resistance
of the switches. The value of this resistance is typically 100 Ω.
Capacitor C2 represents the ADC sampling capacitor and is
typically 16 pF.
VDD
D
C1
FACTORY CALIBRATION
The ADIS16350 provides a factory calibration that simplifies
the process of integrating it into system level designs. This
calibration provides correction for initial sensor bias and
sensitivity, power supply variation, axial alignment, and linear
acceleration (gyroscopes). An extensive, three-dimensional
characterization, provides the basis for generating correction
tables for each individual sensor. The ADIS16355 provides the
same calibration, over temperature.
D
R1 C2
06522-023
The core angular rate sensor (gyroscope) used in the ADIS16350
operates on the principle of a resonator gyroscope. Two polysilicon sensing structures each contain a dither frame, which is
electrostatically driven to resonance. This provides the necessary
velocity element to produce a Coriolis force during rotation. At
two of the outer extremes of each frame, orthogonal to the
dither motion, are movable fingers placed between fixed 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.
AUXILIARY ADC FUNCTION
Figure 28. Equivalent Analog Input Circuit
Conversion Phase: Switch Open
Track Phase: Switch Closed
For ac applications, removing high frequency components from
the analog input signal is recommended by the use of a low-pass
filter on the analog input pin.
In applications where harmonic distortion and signal-to-noise
ratios are critical, the analog input must be driven from a low
impedance source. Large source impedances significantly affect
the ac performance of the ADC. This can necessitate the use of
an input buffer amplifier. When no input amplifier is used to drive
the analog input, the source impedance should be limited to
values lower than 1 kΩ.
Rev. PrG | Page 12 of 28
ADIS16355
BASIC OPERATION
The ADIS16350 is designed for simple integration into system
designs, requiring only a 5.0 V power supply and a four-wire,
industry standard serial peripheral interface (SPI). All outputs and
user-programmable functions are handled by a simple register
structure. Each register is 16 bits in length and has its own
unique bit map. The 16 bits in each register consist of an upper
byte (D8 to D15) and a lower byte (D0 to D7), each with its own
6-bit address.
Writing to Registers
SERIAL PERIPHERAL INTERFACE (SPI)
Reading the contents of a register requires a modification to the
sequence illustrated in Figure 29. In this case, the first two bits
in the DIN sequence are 0, followed by the address of the register.
Each register has two addresses (an upper address and a lower
address), but either one can be used to access the entire 16 bits of
data. The final 8 bits of the DIN sequence are irrelevant and can be
counted as “don’t cares” during a read command. During the next
data frame, the DOUT sequence contains the register’s 16-bit
data, as shown in Figure 30. Although a single read command
requires two separate data frames, the full duplex mode
minimizes this overhead, requiring only one extra data frame when
continuously sampling.
Figure 29 displays a typical data frame for writing a command
to a control register. In this case, the first bit of the DIN sequence
is a 1, followed by a 0, the 6-bit address of the target register,
and the 8-bit data command. Because each write command
covers a single byte of data, two data frames are required when
writing the entire 16-bit space of a register.
Reading from Registers
The ADIS16350 serial peripheral interface (SPI) port includes
four signals: chip select (CS), serial clock (SCLK), data input
(DIN), and data output (DOUT). The CS line enables the
ADIS16350 SPI port and frames each SPI event. When this
signal is high, the DOUT line is in a high impedance state and
the signals on DIN and SCLK have no impact on operation. A
complete data frame contains 16 clock cycles. Because the SPI
port operates in full duplex mode, it supports simultaneous,
16-bit receive (DIN) and transmit (DOUT) functions during the
same data frame. This enables one to configure the next read
cycle, while at the same time, receiving the data associated with
the previous configuration.
Refer to Table 2, Figure 2, and Figure 3 for detailed information
regarding timing and operation of the SPI port.
DATA FRAME
CS
SCLK
W/R
A5
A4
A3
A2
A1
A0
REGISTER ADDRESS
WRITE = 1
READ = 0
DC7
DC6
DC5 DC4
DC3
DC2
DC1
DATA FOR WRITE COMMANDS
DON’T CARE FOR READ COMMANDS
DC0
06522-024
DIN
Figure 29. DIN Bit Sequence
CS
DATA FRAME
DATA FRAME
SCLK
W/R BIT
DOUT
ADDRESS
DON’T CARE
NEXT COMMAND
ZERO
BASED ON PREVIOUS COMMAND
16-BIT REGISTER CONTENTS
Figure 30. SPI Sequence for Read Commands
Rev. PrG | Page 13 of 28
06522-025
DIN
ADIS16355
DATA OUTPUT REGISTER ACCESS
The ADIS16350 provides access to a full 6DOF set of calibrated
motion measurements, power supply measurements, temperature measurements, and an auxiliary 12-bit ADC channel.
This output data is continuously updating internally, regardless
of user read rates. Table 6 describes the structure of all
ADIS16350 output data registers.
indicates a system error or an alarm condition that can result
from various conditions, such as a power supply out of range
condition. See the Status and Diagnostics section for more
details. The output data is either 12 bits or 14 bits in length. For
the 12-bit output data, Bit D13 and Bit D12 are assigned “don’tcare” status.
Table 6. Output Register Bit Map
The output data register map is located in Table 7 and provides
all of the necessary details for accessing each register’s data.
Table 8 displays the output coding for the gyroscope output
registers and Table 9 provides output coding for the acceleration
registers. Figure 31 provides an example of an SPI read cycle for
the XGYRO_OUT register.
MSB
LSB
ND
EA
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
The MSB holds the new data (ND) indicator. When the output
registers are updated with new data, the ND bit goes to a 1 state.
After the output data is read, it returns to a 0 state. The EA bit
Table 7. Data Output Register Information
Name
SUPPLY_OUT
XGYRO_OUT
YGYRO_OUT
ZGYRO_OUT
XACCL_OUT
YACCL_OUT
ZACCL_OUT
XTEMP_OUT2
YTEMP_OUT2
ZTEMP_OUT2
AUX_ADC
1
2
Function
Power Supply Measurement
X-axis Gyroscope Output Measurement
Y-axis Gyroscope Output Measurement
Z-axis Gyroscope Output Measurement
X-axis Acceleration Output Measurement
Y-axis Acceleration Output Measurement
Z-axis Acceleration Output Measurement
X-axis Gyroscope Sensor Temperature Measurement
Y-axis Gyroscope Sensor Temperature Measurement
Z-axis Gyroscope Sensor Temperature Measurement
Auxiliary Analog Input Data
Addresses
0x03, 0x02
0x05, 0x04
0x07, 0x06
0x09, 0x08
0x0B, 0x0A
0x0D, 0x0C
0x0F, 0x0E
0x11, 0x10
0x13, 0x12
0x15, 0x14
0x17, 0x16
Data
Length
12 bits
14 bits
14 bits
14 bits
14 bits
14 bits
14 bits
12 bits
12 bits
12 bits
12 bits
Data Format
Binary
Twos Complement
Twos Complement
Twos Complement
Twos Complement
Twos Complement
Twos Complement
Twos Complement
Twos Complement
Twos Complement
Binary
Scale Factor
(per LSB)
1.8315 mV
0.07326 °/s1
0.07326 °/s1
0.07326 °/s1
2.522 mg
2.522 mg
2.522 mg
0.1453°C
0.1453°C
0.1453°C
0.6105 mV
Hex Output
0x0444
0x0222
0x0001
0x0000
0x3FFF
0x3DDE
0x3BBC
Decimal
1092
546
1
0
−1
−546
−1092
Assumes that the scaling is set to 300°/s.
Typical condition, 25°C = 0 LSB
Table 8. Output Coding Example, XGYRO_OUT, YGYRO_OUT, and ZGYRO_OUT1, 2
±300°/s Range
80°/s
40°/s
0.07326°/s
0°/s
−0.07326°/s
−40°/s
−80°/s
1
2
Rate of Rotation
±150°/s Range
40°/s
20°/s
0.03663°/s
0°/s
−0.03663°/s
−20°/s
−40°/s
±75°/s Range
20°/s
10°/s
0.018315°/s
0°/s
−0.018315°/s
−10°/s
−20°/s
Binary Output
00 0100 0100 0100
00 0010 0010 0010
00 0000 0000 0001
00 0000 0000 0000
11 1111 1111 1111
11 1101 1101 1110
11 1011 1011 1100
Two MSBs have been masked off and are not considered in the coding.
Zero offset null performance are assumed.
Rev. PrG | Page 14 of 28
ADIS16355
Table 9. Output Coding Example, XACCL_OUT, YACCL_OUT, and ZACCL_OUT1, 2
Acceleration (g)
2.522
1
0.002522
0
−0.002522
−1
−2.522
2
Hexadecimal Output
0x03E8
0x018D
0x0001
0x0000
0x3FFF
0x3E73
0x3C18
Decimal
1000
397
1
0
−1
−397
−1000
Two MSBs have been masked off and are not considered in the coding.
Zero offset null performance are assumed.
CS
SCLK
DIN
W/R BIT = 0
ADDRESS = 000101
DOUT
DATA = 1011 1101 1101 1110
NEW DATA, NO ALARM, XGYRO_OUT = –40°/s
NOTE: ±300°/s DYNAMIC RANGE SETTING
Figure 31. Example Read Cycle
Rev. PrG | Page 15 of 28
06522-026
1
Binary Output
00 0011 1110 1000
00 0001 1000 1101
00 0000 0000 0001
00 0000 0000 0000
11 1111 1111 1111
11 1110 0111 0011
11 1100 0001 1000
ADIS16355
PROGRAMMING AND CONTROL
CONTROL REGISTER OVERVIEW
CONTROL REGISTER STRUCTURE
The ADIS16350 offers many programmable features controlled
by writing commands to the appropriate control registers using the
SPI. The following sections describe these controls and specify
each function, along with the corresponding register configuration. The features available for configuration in this register
space are:
The ADIS16350 uses a temporary, RAM-based memory
structure to facilitate the control registers displayed in Table 10.
The operational configuration is stored in a flash memory
structure that automatically loads into the control registers
during the start-up sequence. Each nonvolatile register has a
corresponding flash memory location for storing the latest
configuration contents. The contents of each nonvolatile register must be stored to flash manually.
•
Calibration
•
Global commands
•
Operational control
•
Sample rate
•
Power management
•
Digital filtering
•
Dynamic range
•
DAC output
•
Digital input/output
•
Operational status and diagnostics
•
Self test
•
Status conditions
•
Alarms
Note that the contents of the control register are only nonvolatile
when they are stored to flash. The flash update command, made
available in the COMMAND register, provides this function.
The endurance register provides a counter, which allows for
reliability management against the flash memory’s write cycle
specification.
Table 10. Control Register Mapping
Register Name
ENDURANCE
Type
R
Volatility
Nonvolatile
XGYRO_OFF
YGYRO_OFF
ZGYRO_OFF
XACCL_OFF
YACCL_OFF
ZACCL_OFF
ALM_MAG1
ALM_MAG2
ALM_SMPL1
ALM_SMPL2
ALM_CTRL
AUX_DAC
GPIO_CTRL
MSC_CTRL
SMPL_PRD
SENS/AVG
SLP_CNT
STATUS
COMMAND
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
W
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Nonvolatile
Volatile
Volatile
Nonvolatile1
Nonvolatile
Nonvolatile
Volatile
Volatile
N/A
1
Addresses
0x00, 0x01
0x02 to 0x17
0x18, 0x019
0x1A, 0x1B
0x1C, 0x1D
0x1E, 0x1F
0x20, 0x21
0x22, 0x23
0x24, 0x25
0x26, 0X27
0x28, 0x29
0x2A, 0x2B
0x2C, 0x2D
0x2E, 0x2F
0x30, 0x31
0x32, 0x33
0x34, 0x35
0x36, 0x37
0x38, 0x39
0x3A, 0x3B
0x3C, 0x3D
0x3E, 0x3F
Bytes
2
22
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Function
Flash memory write count
Output data
Reserved
X-axis gyroscope bias offset factor
Y-axis gyroscope bias offset factor
Z-axis gyroscope bias offset factor
X-axis acceleration bias offset factor
Y-axis acceleration bias offset factor
Z-axis acceleration bias offset factor
Alarm 1 amplitude threshold
Alarm 2 amplitude threshold
Alarm 1 sample period
Alarm 2 sample period
Alarm control
Auxiliary DAC data
Auxiliary digital input/output control
Miscellaneous control
Internal sample period (rate) control
Dynamic range/digital filter control
Sleep mode control
System status
System command
The contents of the lower byte are nonvolatile; the contents of the lower byte are volatile.
Rev. PrG | Page 16 of 28
Reference Tables
Table 30
Table 7
Table 11, Table 12
Table 11, Table 12
Table 11, Table 12
Table 13, Table 14
Table 13, Table 14
Table 13, Table 14
Table 33, Table 34
Table 33, Table 34
Table 35, Table 36
Table 35, Table 36
Table 37, Table 38
Table 23, Table 24
Table 25, Table 26
Table 28, Table 29
Table 17, Table 18
Table 21, Table 22
Table 19, Table 20
Table 31, Table 32
Table 15, Table 16
ADIS16355
CALIBRATION
Precision Automatic Bias Null Calibration
For applications that require point of use calibration, the
ADIS16350 provides bias correction registers for all six sensors.
Table 11, Table 12, Table 13, and Table 14 provide the details
required for using these registers to calibrate the ADIS16350
sensors.
The ADIS16350 also provides a single-command function that
incorporates the optimal averaging time for generating the
appropriate bias correction factors for all three gyroscope sensors. This command requires approximately 30 seconds. For
optimal calibration accuracy, the device should be stable (no
motion) for this entire period. Once it has started, a reset
command is required to stop it prematurely, if required. The
following sequence starts this calibration option (See Table 16):
Table 11. Gyroscope Bias Correction Registers
Register
XGYRO_OFF
YGYRO_OFF
ZGYRO_OFF
Addresses
0x1B, 0x1A
0x1D, 0x1C
0x1F, 0x1E
Common Parameters
Default value = 0x0000
Scale = 0.018315°/s per LSB
Twos complement, read/write
Description
Not used
Data bits, typical adjustment range = ±75°
Write 0x02 to Address 0x3E
Table 13. Accelerometer Bias Correction Registers
Register
XACCL_OFF
YACCL_OFF
ZACCL_OFF
Addresses
0x21, 0x20
0x23, 0x22
0x25, 0x24
Common Parameters
Default value = 0x0000
Scale = 2.522 mg per LSB
Twos complement, read/write
The ADIS16350 provides compensation for acceleration
influences on the gyroscopes’ bias behavior, using the
MSC_CTRL register.
Linear Acceleration Origin Alignment
Description
Not used
Data bits, typical adjustment range = ±5.16 g
The ADIS16350 provides origin alignment for the accelerometers, to the point of percussion (see Figure 4), using the
MSC_CTRL register.
Manual Bias Calibration
Since each offset bias register has read/write access, the bias of
each sensor is adjustable. For example, if an output offset of
0.18 °/s is observed in the Z-axis gyroscope, the ZGYRO_OFF
register provides the calibration factor necessary to improve the
accuracy. Using its sensitivity of 0.018315°/s, an adjustment of
−10 LSBs is required. The twos complement, hexadecimal code
of −10 LSBs is 0x1FF6.
To implement this calibration factor, use the following
pseudo code:
Write 0xF6 to Address 0x1E, then write 0x1F to
Address 0x1F
This step reduces the 0.18°/s error to 0.00315°/s.
Automatic Bias Null Calibration
The ADIS16350 provides a single-command, automatic bias
calibration for all three-gyroscope sensors. The COMMAND
register provides this function, which measures all three
gyroscope output registers, then loads the three bias correction
registers with values that return their outputs to zero (null). A
single register write command starts this process (see Table 16).
Write 0x01 to Address 0x3E
Linear Acceleration Bias Compensation (Gyroscopes)
Set Bit 7 of Address 0x34 to 1 (see Table 29)
Table 14. Accelerometer Bias Correction Register Bits
Bits
[15:12]
[11:0]
Restoring Factory Calibration
The ADIS16350 factory calibration can be restored by returning
the contents of each bias correction register to their default
value of zero. This command also flushes all of the data from
the digital filter taps. To accomplish this function for all sixsensor signal paths (see Table 16):
Table 12. Gyroscope Bias Correction Register Bits
Bits
[15:13]
[12:0]
Write 0x10 to Address 0x3E
Set Bit 6 of Address 0x34 to a 1 (see Table 29)
GLOBAL COMMANDS
The ADIS16350 provides global commands for common
operations such as calibration, flash update, auxiliary DAC
latch, and software reset. Each of these global commands has a
unique control bit assigned to it in the COMMAND register and
is initiated by writing a 1 to its assigned bit.
The flash update command writes the contents of each nonvolatile register into flash memory for storage. This process
takes approximately 100 ms and requires the power supply
voltage to be within specification for the duration of the event.
Note that this operation also automatically follows the auto null,
precision auto null, and factory reset commands. After waiting
the appropriate time for the flash update to complete, verify
successful completion by reading the STATUS register (flash
update error = zero, if successful).
The DAC latch command loads the contents of AUX_DAC into
the DAC latches. Since the AUX_DAC contents must be updated
one byte at a time, this command ensures a stable DAC output
voltage during updates. Finally, the software reset command
sends the ADIS16350 digital processor into a restart sequence,
effectively accomplishing the same tasks as the RST line.
Rev. PrG | Page 17 of 28
ADIS16355
Table 15. COMMAND Register Definition
Address
0x3F, 0x3E
Default
N/A
Format
N/A
Access
Write only
Table 16. COMMAND Bit Descriptions
Bits
[15:8]
[7]
[6:5]
[4]
[3]
[2]
[1]
[0]
Description
Not used
Software reset command
Not used
Precision auto null command
Flash update command
Auxiliary DAC data latch
Factory calibration restore command
Auto null command
The sample rate setting has a direct impact on the SPI data rate
capability. For SMPL_PRD settings less than, or equal to 0x09
(fast mode), the SPI SCLK can run at a rate up to 2.0 MHz. For
SMPL_PRD settings greater than 0x09 (normal mode), the SPI
SCLK can run at a rate up to 300 kHz.
The sample rate setting also affects the power dissipation.
The normal mode power dissipation is approximately 67% less
than the fast mode power dissipation. The two different modes
of operation offer a system-level trade-off between performance
(sample rate, serial transfer rate) and power dissipation.
Power Management
In addition to offering two different performance modes for
power optimization, the ADIS16350 offers a programmable
shutdown period. Writing the appropriate sleep time to the
SLP_CNT register shuts the device down for the specified time.
The following example illustrates this relationship:
OPERATIONAL CONTROL
Internal Sample Rate
The internal sample rate defines how often data output variables
are updated, independent of the rate at which they are read out
on the SPI port. The SMPL_PRD register controls the ADIS16350
internal sample rate and has two parts: a time base and a multiplier. The sample period can be calculated using the following
equation:
TS = TB × (NS + 1)
where:
TS is the sample period.
TB is the time base.
NS is the multiplier.
Bits[7:0] = 00000110 = 6 codes = 3 seconds
After completing the sleep period, the ADIS16350 returns to
normal operation. If measurements are required before sleep
period completion, the ADIS16350 can be awakened by pulling
the CS line to down to a 0 state, then returning it back to a 1
state. Otherwise, the CS line must be kept in a 1 (high) state to
maintain sleep mode.
When writing a sleep time to the SLP_CNT register, the time
between the 16th SCLK edge and the CS rising edge must be less
than 10 μs in fast mode and 80 μs on normal mode.
The default value is the minimum register setting, 0x01, which
corresponds to the maximum sample rate of 819.2 samples per
second. The contents of this register are nonvolatile.
Table 19. SLP_CNT Register Definition
Address
0x3B, 0x3A
1
Table 17. SMPL_PRD Register Definition
Address
0x37, 0x36
Default
0x0001
Format
N/A
Format
Binary
Access
R/W
Scale is the weight of each LSB.
Bits
[15:8]
[7:0]
Description
Not used
Time base, 0 = 0.61035 ms, 1 = 18.921 ms
Multiplier (add 1 before multiplying by the time base)
An example calculation of the sample period for the device is
If SMPL_PRD = 0x0007, Bits[7:0] = 00000111
Bit 7 = 0 → TB = 0.61035 ms
Bits[6:0] = 000000111 = 7 = NS
TS = TB × (NS + 1) = = 0.61035 ms × (7 + 1) = 4.8828 ms
fS = 1∕TS = 204.8 SPS
Default
0x0000
Table 20. SLP_CNT Bit Descriptions
Access
R/W
Table 18. SMPL_PRD Bit Descriptions
Bits
[15:8]
[7]
[6:0]
Scale1
0.5 sec
Description
Not used
Data bits
Digital Filtering
Each sensor’s signal conditioning circuit has an analog bandwidth
of approximately 350 Hz. The ADIS16350 provides a Bartlett
Window FIR filter for additional noise reduction on all of the
output data registers. The SENS/AVG register stores the number
of taps in this filter in seven, power-of-two step sizes (that is,
N = 2M = 1, 2, 4, 16, 32, and 64).
Filter setup requires one simple step: write the appropriate M
factor to the assigned bits in the SENS/AVG register. The bit
assignments are listed in Table 22. The frequency response
relationship for this filter is:
H B ( f ) = H A2 ( f ) H A ( f ) =
Rev. PrG | Page 18 of 28
sin(π × N × f × t s )
N × sin(π × f × t s )
ADIS16355
0
Table 23. AUX_DAC Register Definition
Address
0x31, 0x30
–20
Default
0x0000
Format
Binary
Access
R/W
MAGNITUDE (dB)
–40
Table 24. AUX_DAC Bit Descriptions
–60
Bits
[15:12]
[11:0]
–80
Description
Not used
Data bits
0x0000 – 0 V output, 0x0FFF – 2.5 V output
–100
N=2
N=4
N = 16
N = 64
–140
0.001
General-Purpose Input/Output
0.01
0.1
1
FREQUENCY (f/fS)
06522-027
–120
Figure 32. Bartlett Window FIR Frequency Response
Dynamic Range
The ADIS16350 provides three dynamic range settings: ±75°/s,
±150°/s, and ±300°/s. The lower dynamic range settings (75, 150)
limit the minimum filter tap sizes in order to maintain the resolution as the measurement range decreases. The recommended
order for programming the SENS/AVG register is upper byte
(sensitivity) followed by lower byte (filtering). The contents of the
SENS/AVG register are nonvolatile.
Table 21. SENS/AVG Register Definition
Address
0x39, 0x38
Default
0x0402
Format
N/A
Access
R/W
Table 22. SENS/AVG Bit Descriptions
Bits
[15:11]
[10:8]
Value
100
010
001
[7:3]
[2:0]
Description
Not used
Measurement range (sensitivity) selection
300°/s (default condition)
150°/s, filter taps ≥ 4 (Bit 2:0 ≥ 0x02)
75°/s, filter taps ≥16 (Bit 2:0 ≥ 0x04)
Not used
Filter tap setting, M = decimal of these bits
(number of taps, N = 2M)
The ADIS16350 provides two general-purpose pins that enable
digital input/output control using the SPI. The GPIO_CTRL
control register establishes the configuration of these pins and
handles the SPI-to-pin controls. Each pin provides the flexibility of both input (read) and output (write) operations.
The contents of this register are volatile. For example, writing a
0x0202 to this register establishes Line 2 as an output and sets
its level as a 1. Writing 0x0000 to this register establishes both
lines as inputs, and their status can be read through Bit 8 and Bit 9
of this register.
The digital input/output lines are also available for data-ready and
alarm/error indications. In the event of conflict, the following
priority structure governs the digital input/output configuration:
1.
MSC_CTRL
2.
ALM_CTRL
3.
GPIO_CTRL
Table 25. GPIO_CTRL Register Definition
Address
0x33, 0x32
Format
N/A
Access
R/W
Table 26. GPIO_CTRL Bit Descriptions
Bits
[15:10]
[9]
[8]
Auxiliary DAC
The auxiliary DAC provides a 12-bit level adjustment function.
The AUX_DAC register controls the operation of this feature. It
offers a rail-to-rail buffered output that has a range of 0 V to 2.5 V.
The DAC can drive its output to within 5 mV of the ground
reference when it is not sinking current. As the output
approaches ground, the linearity begins to degrade (100 LSB
beginning point). As the sink current increases, the nonlinear
range increases. The DAC output latch function, contained in
the COMMAND register, provides continuous operation while
writing each byte of this register. The contents of this register
are volatile, which means that the desired output level must be
set after every reset and power cycle event.
Default
0x0000
[7:2]
[1]
[0]
Rev. PrG | Page 19 of 28
Description
Not used
General-purpose input/output line 2 data level
1 = high, 0 = low
General-purpose input/output line 1 data level
1 = high, 0 = low
Not used
General-purpose input/output line 2, data direction
control
1 = output, 0 = input
General-purpose input/output line 1, data direction
control
1 = output, 0 = input
ADIS16355
STATUS AND DIAGNOSTICS
Self Test
The ADIS16350 provides a number of status and diagnostic
functions. Table 27 provides a summary of these functions,
along with their appropriate control registers.
The MSC_CTRL register also provides a self-test function,
which verifies the MEMS sensor’s mechanical integrity. There
are two different self-test options: (1) internal self-test and (2)
external self-test.
Table 27. Status and Diagnostic Functions
Function
Data-ready input/output indicator
Self-test, mechanical check for sensor element
Status: Check for predefined error conditions
Flash memory endurance
Alarms: Configure and check for user-specific
conditions
Register
MSC_CTRL
MSC_CTRL
STATUS
ENDURANCE
ALM_MAG1
ALM_MAG2
ALM_SMPL1
ALM_SMPL2
ALM_CTRL
Data-Ready Input/Output Indicator
The data-ready function provides an indication of updated
output data. The MSC_CTRL register provides the opportunity
to configure either of the general-purpose input/output pins (DIO1
and DIO2) as a data-ready indicator signal.
Table 28. MSC_CTRL Register Definition
Address
0x35, 0x34
Default
0x0000
Format
N/A
Access
R/W
Table 29. MSC_CTRL Bit Descriptions
Bits
[15:11]
[10]
[9]
[8]
[7]
[6]
[5:3]
[2]
[1]
[0]
Description
Not used
Internal self-test enable (clears on completion)
1 = enabled, 0 = disabled
Manual self-test, negative stimulus
1 = enabled, 0 = disabled
Manual self-test, positive stimulus
1 = enabled, 0 = disabled
Linear acceleration bias compensation for gyroscopes
1 = enabled, 0 = disabled
Linear accelerometer origin alignment
1 = enabled, 0 = disabled
Not used
Data-ready enable
1 = enabled, 0 = disabled
Data-ready polarity
1 = active high, 0 = active low
Data-ready line select
1 = DIO2, 0 = DIO1
The internal test provides a simple, two-step process for
checking the MEMS sensor:.
1.
Start the process by writing a 1 to Bit 10 in the MSC_CTRL
register.
2.
Check the result by reading Bit 5 of the STATUS register.
If a failure is indicated, then Bit 10 to Bit 15 of the STATUS
register indicates which of the six sensors it is associated with.
The entire cycle takes approximately 35 ms and the output data
is not available during this time. The external self-test is a static
condition that can be enabled and disabled. In this test, both
positive and negative gyroscope MEMS sensor movements are
available. For the accelerometers, only positive MEMS sensor
movement is available.
After writing to the appropriate control bit, the output registers
reflect the changes after a delay that reflects the response time
associated with the sensor/signal conditioning circuit. For
example, the standard 350 Hz bandwidth reflects an exponential response with a time constant of 0.45 ms. Note that the
digital filtering impacts this delay as well. The appropriate bit
definitions for self-test are listed in Table 28 and Table 29.
Flash Memory Endurance
The ENDURANCE register maintains a running count of writes
to the flash memory. It provides up to 32,768 counts. Note that
if this count is exceeded, the register wraps around, and goes
back to zero, before beginning to increment again.
Table 30. ENDURANCE Register Definition
Address
0x01, 0x00
Rev. PrG | Page 20 of 28
Default
N/A
Format
Binary
Access
Read only
ADIS16355
Status Conditions
Alarms
The STATUS register contains the following error condition
flags: alarm conditions, self-test status, overrange, SPI communication failure, control register update failure, and power supply
out of range. See Table 31 and Table 32 for the appropriate
register access and bit assignment for each flag.
The ADIS16350 provides two independent alarm options for
event detection. Event detections occur when output register
data meets the configured conditions. Configuration options are:
The bits assigned for checking power supply range and sensor
overrange automatically reset to zero when the error condition
no longer exists. The remaining error flag bits in the STATUS
register require a read in order to return them to zero. Note that
a STATUS register read clears all of the bits to zero. If any error
conditions remain, the bits revert to 1 during the next internal
output register update cycle.
•
•
•
•
Table 31. STATUS Register Definition
Address
0x3D, 0x3C
Default
0x0000
Format
N/A
Access
Read only
Table 32. STATUS Bit Descriptions
Bits
[15]
[14]
[13]
[12]
[11]
[10]
[9]
[8]
[7:6]
[5]
[4]
[3]
[2]
[1]
[0]
Description
Z-axis accelerometer self diagnostic error flag
1 = failure, 0 = passing
Y-axis accelerometer self diagnostic error flag
1 = failure, 0 = passing
X-axis accelerometer self diagnostic error flag
1 = failure, 0 = passing
Z-axis gyroscope self diagnostic error flag
1 = failure, 0 = passing
Y-axis gyroscope self diagnostic error flag
1 = failure, 0 = passing
X-axis gyroscope self diagnostic error flag
1 = failure, 0 = passing
Alarm 2 status
1 = active, 0 = inactive
Alarm 1 status
1 = active, 0 = inactive
Not used
Self-test diagnostic error flag
1 = error condition, 0 = normal operation
Sensor over range (any of the six)
1 = error condition, 0 = normal operation
SPI communications failure
1 = error condition, 0 = normal operation
Control register update failed
1 = error condition, 0 = normal operation
Power supply in range above 5.25 V
1 = above 5.25 V, 0 = below 5.25 V (normal)
Power supply below 4.75 V
1 = below 4.75 V, 0 = above 4.75 V (normal)
•
All output data registers are available for monitoring as the
source data.
The source data can be filtered or unfiltered.
Comparisons can be static or dynamic (rate of change).
The threshold levels and times are configurable.
Comparison can be greater than or less than.
The ALM_MAG1 register and the ALM_MAG2 register both
establish the threshold level for detecting events. These registers
take on the format of the source data and provide a bit for
establishing the greater than/less than comparison direction.
When making dynamic comparisons, the ALM_SMPL1 register
and the ALM_SMPL2 register establish the number of averages
taken for the source data as a reference for comparison. In this
configuration, each subsequent source data sample is subtracted
from the previous one, establishing an instantaneous delta. The
ALM_CTRL register controls the source data selection, static/
dynamic selection, filtering selection, and digital input/output
usage for the alarms.
The rate of change calculation is
YC =
1
N DS
N DS
∑ y(n + 1) −y(n)
n =1
Rate of change alarm is determined by comparing
YC with M C according to ALM_MAG1 /2 settings
where:
NDS is the number of samples in ALM_SMPL1 and
ALM_SMPL2.
y(n) is the sampled output data.
MC is the magnitude for comparison in ALM_MAG1 and
ALM_MAG2.
YC is the factor to compare with MC.
Rev. PrG | Page 21 of 28
ADIS16355
Table 33. ALM_MAG1 and ALM_MAG2 Register Definitions
Table 38. ALM_CTRL Bit Designations
Register
ALM_MAG1
ALM_MAG2
Bits
[15:12]
Addresses
0x27, 0x26
0x29, 0x28
Default
0x0000
0x0000
Format
N/A
N/A
Access
R/W
R/W
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
Table 34. ALM_MAG1 and ALM_MAG2 Bit Designations
Bits
[15]
[14]
[13:0]
Description
Comparison polarity: 1 = greater than, 0 = less than
Not used
Data bits, format matches source data format
Table 35. ALM_SMPL1 and ALM_SIMPL2 Register Definitions
Registers
ALM_SMPL1
ALM_SMPL2
Addresses
0x2B, 0x2A
0x2D, 0x2C
Default
0x0000
0x0000
Format
Binary
Binary
Access
R/W
R/W
Table 36. ALM_SMPL1 and ALM_SIMPL2 Bit Designations
Bit
[15:8]
[7:0]
Description
Not used
Data bits
Addresses
0x2F, 0x2E
Default
0x0000
[11:8]
[7]
[6]
Table 37. ALM_CTRL Register Definition
Format
N/A
Access
R/W
Value
[5]
[4]
[3]
[2]
[1]
[0]
Rev. PrG | Page 22 of 28
Description
Alarm 2 source selection
Disable
Power supply output
X-axis gyroscope output
Y-axis gyroscope output
Z-axis gyroscope output
X-axis accelerometer output
Y-axis accelerometer output
Z-axis accelerometer output
X-axis gyroscope temperature output
Y-axis gyroscope temperature output
Z-axis gyroscope temperature output
Auxiliary ADC output
Alarm 1 source selection (same as Alarm 2)
Rate of change (ROC) enable for Alarm 2
1 = rate of change, 0 = static level
Rate of change (ROC) enable for Alarm 1
1 = rate of change, 0 = static level
Not used
Comparison data filter setting
1 = filtered data, 0 = unfiltered data
Not used
Alarm output enable
1 = enabled, 0 = disabled
Alarm output polarity
1 = active high, 0 = active low
Alarm output line select
1 = DIO2, 0 = DIO1
ADIS16355
APPLICATIONS INFORMATION
INSTALLATION GUIDELINES
Electrical Connections
Installing the ADIS16350 requires two steps: mechanical
attachment of the body followed by the electrical connection.
This device is designed for post-solder reflow installation. It is
not designed to survive the temperatures associated with
normal solder reflow processes.
The electrical interface for the ADIS16350 is a single connector,
which is attached to a flexible circuit extension, and strengthened by a rigid 0.7 mm thick PCB (FR4 equivalent material).
Mechanical Attachment
The ADIS16350 is designed for simple mechanical attachment.
The open mounting tabs on each side of the body provide
enough room for 2 mm (or 2-56) machine screws. Note that
316 stainless steel and aluminum screws are available for use
in this attachment.
When planning the installation process, the primary tradeoff to
consider is the attachment strength advantage of stainless steel
against the nonmagnetic properties of aluminum for systems
that employ magnetic sensors. In addition, the ADIS16350
provides 1.5 mm alignment pinholes, one on each side.
Location accuracy of the mating holes may force the use of
a smaller pin. Figure 33 provides a graphical display of the
mechanical attachment and Figure 34 provides a recommendation for the physical layout of all the holes required for
attaching the ADIS16350.
This connector is a dual-row, 2-12, 1 mm male header, which
mates to Samtec part number CLM-112-02-L-D-A or the
equivalent. The flexible circuit has stress relief points to absorb
environmental stresses, such as temperature cycling and vibration. Figure 34 provides the alignment hole locations for designs
that employ the suggested connector mate. This connection is
held by friction only.
Proper Removal
The flexible circuit interface can tear under excessive force
conditions. An example of excessive force is attempting to
break the electrical connection by pulling on the ADIS16350’s
body, placing all of the stress on the flexible circuit.
The electrical connector must be broken by an appropriate tool,
which is designed to apply even pressure to each side of the
rigid part of the flex cable. The recommended extraction
sequence is to break the mate between the electrical interface,
and then to remove the mechanical attachment hardware.
1.588mm HOLE AND SLOT
FOR ALIGNMENT PINS, 2 EACH
06522-028
DRILL AND TAP HOLE
FOR 2mm (2-56) SCREW,
2 EACH
Figure 33. Mechanical Attachment
Rev. PrG | Page 23 of 28
ADIS16355
DRILL AND INSERT
1.5mm PIN 2×
(HOLE PLACEMENT
INACCURACY MAY
REQUIRE USE OF
UNDERSIZED PIN).
26.700
BSC
DRILL AND TAP FOR
M2 SCREW
AS REQUIRED
2×.
4
BSC
27.700
BSC
10
HOLE 2×.
SEE SAMTEC MOUNTING
DRAWING FOR CLM SERIES SOCKET.
8.350
0.500 BSC
2×
4
BSC
THE LOCATION OF THE MATING CONNECTOR
RELATIVE TO THE ALIGNMENT PINS MAY BE
PLACED ±0.75mm FROM THIS DIMENSION AS
DESIRED. PLACING THIS FURTHER OUT WILL
HAVE LESS BEND/STRESS RELIEF IN THE FLEX.
Figure 34. Hole Locations
Rev. PrG | Page 24 of 28
06522-029
16.810
2×
ADIS16355
OUTLINE DIMENSIONS
31.900
31.700
31.500
23.454
23.200
22.946
9.464
9.210
8.956
(2×)
2.382
BSC
17.41
17.21
17.01
(2×)
1.588
BSC
TOP VIEW
22.964
22.710
22.456
1.588
BSC
10.60
BSC
10.50
BSC
21.410
21.210
21.010
BOTTOM VIEW
5.20
5.00
4.80
(2×)
14.950
14.550
14.150
PIN 24
4.20
4.00
3.80
(2×)
7.18
BSC
1.00
BSC
0.05
BSC
PIN 1
2.00 BSC
12.10
BSC
FRONT VIEW
23.504
23.250
22.996
2.660
2.500
2.340
SIDE VIEW
0.305
BSC (24×)
5.30
5.00
4.70
DETAIL A
1.00
BSC (22×)
4.330
BSC
1.65 BSC
081507-B
DETAIL A
14.00 BSC
Figure 35. ADIS16350 Module with Connector Interface
(ML-24-2)
Dimensions shown in millimeters
ORDERING GUIDE
Model
ADIS16350AMLZ1
ADIS16350/PCBZ1
ADIS16350/EVALZ1
ADIS16355AMLZ1
ADIS16355/PCBZ1
ADIS16355/EVALZ1
1
Temperature Range
−40°C to +85°C
−40°C to +85°C
Package Description
24-Lead Module with Connector Interface
Interface Board
PC Evaluation System
24-Lead Module with Connector Interface
Interface Board
PC Evaluation System
Z = RoHS Compliant Part.
Rev. PrG | Page 25 of 28
Package Option
ML-24-2
ML-24-2
ADIS16355
NOTES
Rev. PrG | Page 26 of 28
ADIS16355
NOTES
Rev. PrG | Page 27 of 28
ADIS16355
NOTES
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
PR06874-0-10/07(PrG)
Rev. PrG | Page 28 of 28
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