ADA4571BRZ [ADI]
Integrated AMR Angle Sensor and Signal Conditioner;
| 型号： | ADA4571BRZ |
| 厂家： | 
ADI |
| 描述： | Integrated AMR Angle Sensor and Signal Conditioner 光电二极管 |
| 文件： | 总22页 (文件大小：499K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Integrated AMR Angle Sensor and Signal
Conditioner
ADA4571
Data Sheet
FEATURES
FUNCTIONAL BLOCK DIAGRAM
VDD
High precision 180° angle sensor
Maximum angular error of 0.5°
ADA4571
VTEMP
GC
TEMPERATURE SENSOR
BRIDGE DRIVER
Analog sine and cosine outputs
Ratiometric output voltages
Low thermal and lifetime drift
SAR or Σ-∆ analog-to-digital converter (ADC) drive capable
Magnetoresistive (MR) bridge temperature compensation mode
Temperature range: −40°C to +150°C
EMI resistant
+
–
EMI
FILTER
VSIN
DRIVER
G = 40
Fault diagnostics
V
DD from 2.7 V to 5.5 V
AMR BRIDGE
SENSORS
BIAS
OSCILLATOR
FAULT DETECTION
Minimum phase delay
Qualified for automotive applications
Available in an 8-lead SOIC package
+
EMI
DRIVER
VCOS
G = 40
–
FILTER
APPLICATIONS
Absolute position measurement (linear and angle)
Brushless dc motor control and positioning
Actuator control and positioning
GND
GND
PD
Contactless angular measurement and detection
Magnetic angular position sensing
Figure 1.
GENERAL DESCRIPTION
The ADA4571 is an anisotropic magnetoresistive (AMR) sensor
with integrated signal conditioning amplifiers and ADC drivers.
The ADA4571 produces two analog outputs that indicate the
angular position of the surrounding magnetic field.
COMPANION PRODUCTS
ADCs: AD7265, AD7266, AD7866, AD7902
Microconverter: ADuCM360
Current Sense Amplifier: AD8418A
Voltage Regulator Design Tool: ADIsimPower
The ADA4571 consists of two die within one package, an AMR
sensor, and a fixed gain (G = 40 nominally) instrumentation
amplifier. The ADA4571 delivers clean and amplified cosine
and sine output signals related to the angle of a rotating
magnetic field. The output voltage range is ratiometric to the
supply voltage.
Additional companion products on the ADA4571 product page
PRODUCT HIGHLIGHTS
1. Contactless angular measurement.
2. Measures magnetic field direction rather than field intensity.
3. Minimum sensitivity to air gap variations.
4. Large working distance.
5. Excellent accuracy, even for weak saturation fields.
6. Minimal thermal and lifetime drift.
7. Negligible hysteresis.
The sensor contains two Wheatstone bridges, at a relative angle
of 45° to one another. A rotating magnetic field in the x-y
sensor plane delivers two sinusoidal output signals with the
double frequency of the angle (α) between sensor and magnetic
field direction. Within a homogeneous field in the x-y plane,
the output signals are independent of the physical placement in
the z direction (air gap).
8. Single chip solution.
The ADA4571 is available in an 8-lead SOIC package.
Rev. 0
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Technical Support
ADA4571* PRODUCT PAGE QUICK LINKS
Last Content Update: 09/21/2017
COMPARABLE PARTS
View a parametric search of comparable parts.
REFERENCE MATERIALS
Press
• Analog Devices' Magnetic Angle Sensor Technology
Delivers Industry’s Highest Performance for Precision DC
Motor Controls
EVALUATION KITS
• ADA4571 Evaluation Board
Technical Articles
• New Sensor Developments Drive BLDC Motor Control
Performance
DOCUMENTATION
Application Notes
• AN-1314: AMR Angle Sensors
• AN-1352: Calibration Procedures for the ADA4571
Data Sheet
DESIGN RESOURCES
• ADA4571 Material Declaration
• PCN-PDN Information
• ADA4571: Integrated AMR Angle Sensor and Signal
Conditioner Data Sheet
• Quality And Reliability
• Symbols and Footprints
User Guides
• UG-1169: Evaluating the ADA4571 Integrated AMR Angle
Sensor and Signal Conditioner
DISCUSSIONS
View all ADA4571 EngineerZone Discussions.
• UG-739: ADA4571 End of Shaft Evaluation Board
SAMPLE AND BUY
Visit the product page to see pricing options.
REFERENCE DESIGNS
• CN0368
TECHNICAL SUPPORT
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number.
DOCUMENT FEEDBACK
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ADA4571
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1ꢀ
Pin Configuration and Descriptions...............................................8ꢀ
Typical Performance Characteristics ..............................................9ꢀ
Terminology.................................................................................... 13ꢀ
Theory of Operation ...................................................................... 14ꢀ
Application Information................................................................ 16ꢀ
Angle Calculation....................................................................... 16ꢀ
Connection to ECU ................................................................... 16ꢀ
Mechanical Tolerances Diagrams ............................................ 18ꢀ
Diagnostics.................................................................................. 19ꢀ
Outline Dimensions....................................................................... 21ꢀ
Ordering Guide .......................................................................... 21ꢀ
Automotive Products................................................................. 21ꢀ
Applications....................................................................................... 1ꢀ
Functional Block Diagram .............................................................. 1ꢀ
General Description......................................................................... 1ꢀ
Companion Products....................................................................... 1ꢀ
Product Highlights ........................................................................... 1ꢀ
Revision History ............................................................................... 2ꢀ
Specifications..................................................................................... 3ꢀ
Magnetic Characteristics............................................................. 3ꢀ
Electrical Characteristics............................................................. 3ꢀ
Absolute Maximum Ratings............................................................ 7ꢀ
Thermal Resistance ...................................................................... 7ꢀ
ESD Caution.................................................................................. 7ꢀ
REVISION HISTORY
10/14—Revision 0: Initial Version
Rev. 0 | Page 2 of 21
Data Sheet
ADA4571
SPECIFICATIONS
MAGNETIC CHARACTERISTICS
Table 1.
Parameter
Value Unit
25 kA/m
Test Conditions/Comments
Magnetic Field Strength, HEXT
The stimulating magnetic field in the x-y sensor plane necessary to ensure the
minimum error as specified in Table 1 and Table 2
Maximum Magnetic Field Rotational
Frequency
50,000 rpm
Reference position for y = 0 µm is the straight connection line of Pin 2 and Pin 7;
the x = 0 µm position is referred to the middle distance of the package top
Reference position for angle Φ = 0° is parallel to the straight connection line
of Pin 2 and Pin 7
Reference Position Error
50
2
µm
Reference Angle Error
Degrees
ELECTRICAL CHARACTERISTICS
ADA4571WH
−40°C ≤ TA ≤ +150°C, VDD = 2.7 V to 5.5 V, CL = 10 nF to GND, RL = 200 kΩ to GND; angle inaccuracies referred to homogenous
magnetic field of 25 kA/m; output signals and offset voltages are related to the common-mode level of VDD/2, unless otherwise stated.
Table 2.
Parameter
Symbol
Test Conditions/Comments
Min
Typ
Max
Unit
ANGULAR PERFORMANCE
Angle Measurement Range
Uncorrected Angular Error1
0
180
5
Degrees
Degrees
Degrees
Degrees
Degrees
αUNCORR
TA = −40°C
TA = 25°C
5
TA = 150°C
5
Single Point Calibration Angular αCAL
Error2, 3
TA = −40°C to +150°C, GC = GND
0.7
TA = −40°C to +150°C, GC = VDD
0.7
0.1
Degrees
Degrees
Dynamic Angular Error4
αDYNAMIC
TA = −40°C to +150°C, rotation frequency =
2000 rpm
0.5
OUTPUT PARAMETERS
Amplitude
VAMP
GC = GND
TA = −40°C
63
41
21
18
56
52
38
35
7
75
53
33
30
77
72
57
55
93
5
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% peak
µs
TA = 25°C
TA = 125°C
TA = 150°C
GC = VDD
TA = −40°C
TA = 25°C
TA = 125°C
TA = 150°C
Output Voltage Range
Output Voltage Low
VO_SWING
VOL
VSIN and VCOS, normal operation
VSIN or VCOS, broken bond wire detected
GC = VDD
Output Referred Offset Voltage
VOFFSET
3.75
3.75
+1
GC = GND
Amplitude Synchronism Error5
Delay Time
Phase Error6
k
−1
tDEL
ΦERR
OE
Rotation frequency = 30,000 rpm
Rotation frequency = 30,000 rpm
2
0.8
Degrees
Degrees
µV rms
Orthogonality Error3
0.05
Output Noise
VNOISE
Bandwidth (BW) = 80 kHz, referred to
output (RTO)
500
60
Output Series Resistance
RO
Normal operation, PD = GND
PD = VDD
Ω
63
kΩ
kHz
Output −3 dB Cutoff Frequency3 f−3dB
Amplifier BW, CL = 10 pF
100
Rev. 0 | Page 3 of 21
ADA4571
Data Sheet
Parameter
Power Supply Rejection3
Symbol
Test Conditions/Comments
Min
Typ
Max
Unit
PSRR
Measured as output variation from VDD/2,
VDD = 2.7 V to 5.5 V, RL = 200 kΩ to GND,
GC = GND or VDD
80
dB
Output Short-Circuit Current
ISC
Short to GND per pin (VSIN, VCOS)
Short to VDD per pin (VSIN, VCOS)
α1 = 0°, α2 = 135°, TA = 25°C
15
20
mA
−15
−18
52
mA
Sensitivity
SEN
mV/°
POWER SUPPLY
Supply Voltage
VDD
ISY
2.7
3.5
5.5
6.5
7
V
Quiescent Supply Current
PD = GND, GC = GND, no load
PD = GND, GC = VDD, no load
PD = VDD, no load
4.5
mA
mA
µA
µs
15
150
Power-Up Time
tPWRUP
To 98% of desired output level after VDD was
reached
To 98% of desired output level after PD cycling
100
30
µs
DIGITAL INPUTS
Input Bias Current (GC)
IB_GC
IB_PD
For GC mode control pin, GC = GND
For GC mode control pin, GC = VDD
For PD pin, PD = GND
µA
µA
µA
µA
3
3
Input Bias Current (PD)
For PD pin, PD = VDD
30
Input Voltage (GC and PD)
High
VIH
VIL
1.4
V
V
Low
0.35
TEMPERATURE SENSOR
Error Over Temperature
Temperature Voltage Range
Temperature Coefficient
VTEMP Output Voltage
VTEMP Output Impedance
VTEMP Load Capacitance
VTEMP Short-Circuit Current
LOAD CAPACITOR
TERR
5
°C
TRANGE
TCO
TA = −40°C to +150°C
0
82
40
22
% VDD
mV/V/°C
% VDD
Ω
3.173
50
TA = 25°C
18
Buffered output
Optional load capacitance
Short-circuit to VDD or GND
0
2
nF
ISC_VTEMP
CL
mA
External Load Capacitance
Between VSIN to GND and VCOS to GND;
solder close to package
10
nF
1 αUNCORR is the total mechanical angular error after arctan computation. This parameter is 100% production tested at 25°C and 150°C. This error includes all sources of
error over temperature before calibration. Error components such as offset, amplitude synchronism, amplitude synchronism drift, thermal offset drift, phase error,
hysteresis, orthogonality error, and noise are included.
2 αCAL is the total mechanical angular error after arctan computation. This error includes all sources of error over temperature after an initial offset (nulling) is performed
at TA = 25°C. Error components such as amplitude synchronism drift, amplifier gain matching, thermal offset drift, phase error, hysteresis, orthogonality error, and
noise are included.
3 Guaranteed through characterization.
4 αDYNAMIC is the total mechanical angular error after arctan computation. This parameter is 100% production tested. This error includes all sources of error over
temperature after a continuous background calibration is performed to correct offset and amplitude synchronism errors. Error components such as phase error,
hysteresis, orthogonality error, noise, and lifetime drift are included.
5 Peak-to-peak amplitude mismatch. k = 100 × VSIN/VCOS.
6 Rotation frequency dependent phase error, after offset correction, amplitude calibration, and arctan calculation.
Rev. 0 | Page 4 of 21
Data Sheet
ADA4571
ADA4571B
−40°C ≤ TA ≤ +125°C, VDD = 2.7 V to 5.5 V, CL = 10 nF to GND, RL = 200 kΩ to GND; angle inaccuracies referred to homogenous
magnetic field of 25 kA/m; output signals and offset voltages are related to the common-mode level of VDD/2, unless otherwise stated.
Table 3.
Parameter
Symbol Test Conditions/Comments
Min
Typ
Max
Unit
ANGULAR PERFORMANCE
Angle Measurement Range
Uncorrected Angular Error1
0
180
3
Degrees
Degrees
Degrees
Degrees
Degrees
αUNCORR
TA = −40°C
TA = 25°C
3
TA = 125°C
4
Single Point Calibration Angular
Error2, 3
αCAL
TA = −40°C to +125°C, GC = GND
0.5
TA = −40°C to +125°C, GC = VDD
0.5
0.1
Degrees
Degrees
Dynamic Angular Error4
Angular Inaccuracy3, 5
αDYNAMIC
∆α
TA = −40°C to +125°C, rotation frequency =
2000 rpm
0.4
After end of line (EOL) calibration for offset
voltage error and amplitude synchronism at
TA = −40°C to +125°C (only 180° range)
0.05
Degrees
OUTPUT PARAMETERS
Amplitude
VAMP
GC = GND
TA = −40°C
63
41
21
56
52
38
7
75
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% VDD
% peak
µs
TA = 25°C
53
TA = 125°C
33
GC = VDD
TA = −40°C
77
TA = 25°C
72
TA = 125°C
57
Output Voltage Range
OutputVoltage Low
VO_SWING
VOL
VSIN and VCOS, normal operation
VSIN or VCOS, broken bond wire detected
GC = VDD
93
3.75
3.75
3.75
+0.75
Output Referred Offset Voltage
VOFFSET
GC = GND
Amplitude Synchronism Error6
Delay Time
Phase Error7
k
−0.75
tDEL
ΦERR
OE
VNOISE
RO
Rotation frequency = 30,000 rpm
Rotation frequency = 30,000 rpm
2
0.8
Degrees
Degrees
µV rms
Ω
Orthogonality Error3
0.05
Output Noise
BW = 80 kHz, RTO
500
50
Output Series Resistance
Normal operation, PD = GND
PD = VDD
63
kΩ
Output −3 dB Cutoff Frequency3
Power Supply Rejection3
f−3dB
Amplifier BW, CL = 10 pF
100
80
kHz
PSRR
Measured as output variation from VDD/2,
VDD = 2.7 V to 5.5 V, RL = 200 kΩ to GND,
GC = GND or VDD
dB
Output Short-Circuit Current
ISC
Short to GND per pin (VSIN, VCOS)
Short to VDD per pin (VSIN, VCOS)
α = 0° and 135°, TA = 25°C
15
20
mA
−15
−18
52
mA
Sensitivity
SEN
mV/°
POWER SUPPLY
Supply Voltage
VDD
ISY
2.7
3.5
5.5
6
V
Quiescent Supply Current
PD = GND, GC = GND, no load
PD = GND, GC = VDD
4.5
mA
mA
µA
µs
6.5
12.5
150
PD = VDD, no load
Power-Up Time
tPWRUP
To 98% of desired output level after VDD was
reached
To 98% of desired output level after PD cycling
100
µs
Rev. 0 | Page 5 of 21
ADA4571
Data Sheet
Parameter
Symbol Test Conditions/Comments
Min
Typ
Max
Unit
DIGITAL INPUTS
Input Bias Current (GC)
IB_GC
IB_PD
For GC mode control pin, GC = GND
For GC mode control pin, GC = VDD
For PD pin, PD = GND
30
µA
µA
µA
µA
3
3
Input Bias Current (PD)
For PD pin, PD = VDD
30
Input Voltage (GC and PD)
High
VIH
VIL
1.4
V
V
Low
0.35
TEMPERATURE SENSOR
Error Over Temperature
Temperature Voltage Range
Temperature Coefficient
VTEMP Output Voltage
VTEMP Output Impedance
VTEMP Load Capacitance
VTEMP Short-Circuit Current
LOAD CAPACITOR
TERR
5
°C
TRANGE
TCO
TA = −40°C to +125°C
0
69
40
22
% VDD
mV/V/°C
% VDD
Ω
3.173
50
TA = 25°C
18
Buffered output
Optional load capacitance
Short-circuit to VDD or GND
0
2
nF
ISC_VTEMP
CL
mA
External Load Capacitance
Between VSIN to GND and VCOS to GND;
solder close to package
10
nF
1 αUNCORR is the total mechanical angular error after arctan computation. This parameter is 100% production tested at 25°C and 150°C. This error includes all sources of
error over temperature before calibration. Error components such as offset, amplitude synchronism, amplitude synchronism drift, thermal offset drift, phase error,
hysteresis, orthogonality error, and noise are included.
2 αCAL is the total mechanical angular error after arctan computation. This error includes all sources of error over temperature after an initial offset (nulling) is performed
at TA = 25°C. Error components such as amplitude synchronism drift, amplifier gain matching, thermal offset drift, phase error, hysteresis, orthogonality error, and
noise are included.
3 Guaranteed through characterization.
4 αDYNAMIC is the total mechanical angular error after arctan computation. This parameter is 100% production tested. This error includes all sources of error over
temperature after a continuous background calibration is performed to correct offset and amplitude synchronism errors. Error components such as phase error,
hysteresis, orthogonality error, noise, and lifetime drift are included.
5 Angular speed <300 rpm. Limited to 180° rotation. The value is calculated only with the third and fifth harmonics of the spectrum of output signal amplitude by the
ideal homogeneous field.
6 Peak-to-peak amplitude mismatch. k = 100 × VSIN/VCOS.
7 Rotation frequency dependent phase error, after offset correction, amplitude calibration, and arctan calculation.
Rev. 0 | Page 6 of 21
Data Sheet
ADA4571
ABSOLUTE MAXIMUM RATINGS
Table 4.
THERMAL RESISTANCE
θJA is specified for the worst case conditions, that is, a device
soldered in a circuit board for surface-mount packages.
Parameter
Rating
Operating Temperature
Storage Temperature
Supply Voltage (VDD)1
−40°C to +150°C
−65°C to +150°C
−0.3 V to +6 V
Table 5. Thermal Resistance
Package Type
θJA
Unit
Output Short-Circuit Duration to GND or VDD Indefinite
8-Lead SOIC
120
°C/W
VTEMP Short-Circuit to GND or VDD
Indefinite
ESD
Human Body Model (HBM)2
Machine Model (MM)3
Charge Device Model (CDM)4
4000 V
300 V
ESD CAUTION
1250 V
1 GC or PD at VDD + 0.3 V.
2 Applicable standard: JESD22-C101.
3 Applicable standard: JESD22-A115.
4 Applicable standard: ESDA/JEDEC JS-001-2011.
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
Rev. 0 | Page 7 of 21
ADA4571
Data Sheet
PIN CONFIGURATION AND DESCRIPTIONS
GC
VCOS
GND
1
2
3
4
8
7
6
5
PD
ADA4571
TOP VIEW
(Not to Scale)
VDD
GND
VTEMP
VSIN
Figure 2. Pin Configuration
Table 6. Pin Function Descriptions
Pin No.
Mnemonic
GC
Description
1
2
3
4
5
6
7
8
Gain Control Mode Enable
Analog Cosine Output
Ground
VCOS
GND
VSIN
Analog Sine Output
Temperature Output
Ground
VTEMP
GND
VDD
Supply Pin
PD
Power-Down Pin, Active High
Rev. 0 | Page 8 of 21
Data Sheet
ADA4571
TYPICAL PERFORMANCE CHARACTERISTICS
40
35
30
25
20
15
10
5
5
4
3
2
1
0
–40°C
+25°C
+125°C
+150°C
0
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
DYNAMIC ANGULAR ERROR (Degrees)
0
90
180
270
360
RELATIVE MECHANICAL ANGLE (Degrees)
Figure 3. Raw Output Waveforms, VDD = 5 V, GC = On, T = 25°C
Figure 6. Dynamic Angular Error, VDD = 5.5 V, GC = Off
0.2
35
30
25
20
15
10
5
–40°C
+25°C
+125°C
+150°C
0.1
0
–0.1
–0.2
0
0
90
180
270
360
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
DYNAMIC ANGULAR ERROR (Degrees)
MECHANICAL ANGLE (Degrees)
Figure 4. Error Waveform After Offset Correction, VDD = 5 V, GC = On
Figure 7. Dynamic Angular Error, VDD = 2.7 V, GC = On
40
35
30
25
20
15
10
5
–40°C
+25°C
+125°C
+150°C
–40°C
+25°C
+125°C
+150°C
35
30
25
20
15
10
5
0
0
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
DYNAMIC ANGULAR ERROR (Degrees)
0
0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
DYNAMIC ANGULAR ERROR (Degrees)
Figure 5. Dynamic Angular Error, VDD = 5.5 V, GC = On
Figure 8. Dynamic Angular Error, VDD = 2.7 V, GC = Off
Rev. 0 | Page 9 of 21
ADA4571
Data Sheet
40
35
30
25
20
15
10
5
35
30
25
20
15
10
5
–40°C
–40°C
+25°C
+125°C
+150°C
+25°C
+125°C
+150°C
0
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
UNCORRECTED ANGULAR ERROR (Degrees)
UNCORRECTED ANGULAR ERROR (Degrees)
Figure 9. Uncorrected Angular Error, VDD = 5.5 V, GC = On
Figure 12. Uncorrected Angular Error, VDD = 2.7 V, GC = Off
40
1.2
–40°C
+25°C
+125°C
+150°C
35
30
25
20
15
10
5
1.0
0.8
0.6
0.4
0.2
0
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
–40
0
40
80
120
UNCORRECTED ANGULAR ERROR (Degrees)
TEMPERATURE (°C)
Figure 10. Uncorrected Angular Error, VDD = 5.5 V, GC = Off
Figure 13. Single Point Calibration Angular Error, VDD = 5.5 V, GC = On
35
1.2
1.0
0.8
0.6
0.4
0.2
0
–40°C
+25°C
+125°C
+150°C
30
25
20
15
10
5
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
–40
0
40
80
120
UNCORRECTED ANGULAR ERROR (Degrees)
TEMPERATURE (°C)
Figure 11. Uncorrected Angular Error, VDD = 2.7 V, GC = On
Figure 14. Single Point Calibration Angular Error, VDD = 5.5 V, GC = Off
Rev. 0 | Page 10 of 21
Data Sheet
ADA4571
1.2
1.0
0.8
0.6
0.4
0.2
5.8
5.6
5.4
5.2
5.0
4.8
4.6
GC OFF (mA)
GC ON (mA)
0
–40
0
40
80
120
–40
0
40
80
120
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 15. Single Point Calibration Angular Error, VDD = 2.7 V, GC = On
Figure 18. Supply Current (ISY) vs. Temperature, VDD = 5 V
1.2
1.0
0.8
0.6
0.4
0.2
0
4.6
4.4
4.2
4.0
3.8
3.6
GC OFF (mA)
GC ON (mA)
–40
0
40
80
120
0
40
80
120
–40
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 16. Single Point Calibration Angular Error, VDD = 2.7 V, GC = Off
Figure 19. Supply Current (ISY) vs. Temperature, VDD = 3 V
7
10
8
5V
3V
6
5
4
3
6
4
2
0
–40
0
40
80
120
2.7
3.1
3.5
3.9
4.3
(V)
4.7
5.1
5.5
TEMPERATURE (°C)
V
DD
Figure 20. Power-Down Current (IPD) vs. Temperature
Figure 17. Supply Current (ISY) vs. Voltage (VDD), T = 25°C
Rev. 0 | Page 11 of 21
ADA4571
Data Sheet
100
90
80
70
60
50
40
30
20
10
100
90
80
70
60
50
40
30
20
10
0
V
V
p-p GC OFF
p-p GC ON
OUT
OUT
0
–40
0
40
80
120
–40
0
40
80
120
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 21. VTEMP Output Voltage vs. Temperature
Figure 23. Output Voltage (VSIN and VCOS) Peak-to-Peak vs.
Temperature (% VDD
)
20
18
16
14
12
10
8
0
–0.1
–0.2
–0.3
–0.4
–0.5
–0.6
–0.7
–0.8
–0.9
–1.0
6
4
ERROR –40°C
ERROR +25°C
ERROR +150°C
2
0
–1.00 –0.75 –0.50 –0.25
0
0.25
0.50
0.75
1.00
300
3000
30000
AMPLITUDE MISMATCH (%)
RPM (Mechanical)
Figure 22. Amplitude Synchronism (% k)
Figure 24. Angular Error Delay vs. RPM (Mechanical)
Rev. 0 | Page 12 of 21
Data Sheet
ADA4571
TERMINOLOGY
Reference Position Error
Uncorrected Angular Error
The uncorrected angular error is defined as the maximum
deviation from an ideal angle reading, when calculating the
angle from VSIN and VCOS without offset calibration.
The reference position error is the absolute mounting position
deviation of the sensor from its nominal placement. The
reference position for Y = 0 µm is the straight connection line of
Pin 2 and Pin 7. The X = 0 µm position is referred to the middle
distance of the package top. The position accuracies are within
a precision of 0.05 mm ( 50 µm) in both the X and Y
direction.
Single Point Calibration Angular Error
The single point calibration angular error is defined as the
maximum deviation from an ideal angle reading, when
calculating the angle from VSIN and VCOS after an initial
calibration for offset voltage at TA = 25°C.
Reference Angle Error
The reference angle error is the absolute mounting rotation
deviation of the sensor from its nominal placement. Marking
the position for angle Φ= 0° position is referred parallel to the
straight connection line of Pin 2 and Pin 7.
Dynamic Angular Error
The dynamic angular error is defined as the maximum
deviation from an ideal angle reading, when calculating the
angle from VSIN and VCOS while a continuous offset calibration is
taken into account.
GC
VCOS
GND
1
2
3
4
8
7
6
5
PD
Phase Error
VDD
GND
VTEMP
The phase error (ΦERR) is defined as the rotation frequency
dependent error due to bandwidth limitation of the instrumen-
tation amplifiers. VSIN and VCOS are impacted by the amplifier
propagation delay, referred to the actual angle direction of the
rotating magnetic field. The typical characteristics value can be
used for a first-order compensation of this error on very high
rotations per minute. For low rotational speed systems, this error
component is negligible and no compensation is necessary.
VSIN
Figure 25. Bonding Arrangement and Sensor Alignment in Package
Output Amplitude Synchronism Error
The output amplitude matching error (k) is defined as the
relationship between both output channel amplitudes at
continuously rotating magnetic excitation of the MR sensor
mathematically expressed as
k = 100% × VSIN_P-P/VCOS_P-P
Rev. 0 | Page 13 of 21
ADA4571
Data Sheet
THEORY OF OPERATION
The ADA4571 is an AMR sensor with integrated signal
conditioning amplifiers and ADC drivers. The ADA4571
produces two analog outputs, sine and cosine, which indicate
the angular position of the surrounding magnetic field.
Electromagnetic interference (EMI) filters at the sensor outputs
and between the first and second stages reject unwanted noise
and interference from appearing in the signal band.
The architecture of the instrumentation amplifier consists of
precision, low noise, zero drift amplifiers that feature a proprietary
chopping technique. This chopping technique offers a low input
offset voltage of 0.3 µV typical and an input offset voltage drift
of 0.02 µV/°C typical. The zero drift design also features
chopping ripple suppression circuitry, which removes glitches
and other artifacts caused by chopping.
The AMR sensing element is designed and manufactured by
Sensitec GmbH.
Figure 27 shows the sine channel, consisting of an AMR sensor
element and the supporting functions for control, filtering,
buffering, and signal amplification. A reference voltage that is
proportional to the supply voltage is generated and it controls
the supply voltage of the sensor bridges. For noise and
electromagnetic compatibility (EMC) suppression purposes, the
bridge supply is low-pass filtered. The bridge output voltages
are amplified by a constant factor (G = 40, GC mode disabled)
and buffered. The single-ended outputs are biased around a
common-mode voltage of VDD/2 and are capable of driving the
inputs of an external ADC referenced to the supply voltage.
Offset voltage errors caused by common-mode voltage swings
and power supply variations are also corrected by the chopping
technique, resulting in a dc common-mode rejection ratio that
is greater than 150 dB. The amplifiers feature low broadband
noise of 22 nV/√Hz and no 1/f noise component. These features
are ideal for amplification of the low level AMR bridge signals
for high precision sensing applications.
In addition, extensive diagnostics are integrated on-chip to self
check sensor and IC conditions.
For optimum use of the ADC input range, the cosine and sine
output voltages track the supply voltage ensuring a ratiometric
configuration. To achieve high signal performance both output
signals are carefully matched in both amplitude and phase. The
amplifier bandwidth is sufficient to ensure low phase delay at
maximum specified rotation speed.
1
2
3
4
8
7
6
5
ADA4571
TOP VIEW
(Not to Scale)
Figure 26. Direction of Homogeneous Magnetic Field for α = 0°
VDD
VDD
VDD
+
–
62.7pF
20pF
+
–
VTEMP
ꢀꢁꢀN
–
ꢂꢃ
AMR
BRIDGE
VSIN
+
–
ADA4571
ꢀꢁꢀN
+
62.7pF
VDD/2
Figure 27. Detailed Internal Diagram of the ADA4571 Sine Channel
Rev. 0 | Page 14 of 21
Data Sheet
ADA4571
DIAGNOSTIC
BAND
93% V
DD
V
COS
V
OFFSET
V p-p
LINEAR
REGION
50% V
DD
V
SIN
7% V
DD
DIAGNOSTIC
BAND
0
90
180
270
360
MAGNETIC $1*/(ꢄꢅĮꢅꢆ'HJUHHVꢇ
Figure 28. Typical Output Waveforms; Sine and Cosine vs. Magnetic Angle
Rev. 0 | Page 15 of 21
ADA4571
Data Sheet
APPLICATIONS INFORMATION
The integrated AMR sensor is designed for applications with a
separate processing IC or electronic control unit (ECU) containing
an ADC with references connected to the supply voltage. With
the ADC input resolution related to VDD in the same way as the
AMR sensor output, the system is inherently ratiometric and the
signal dependency on supply voltage changes are minimized.
To achieve maximum accuracy from the VTEMP output
voltage, perform an initial calibration at a known, controlled
temperature. Then, use the following equation to extract
temperature information:
§
V
CAL
·
¸
¹
V
§
¨
©
·
¸
¹
§
©
·
¸
¹
TEMP
–
– T uTCO
CAL
¨¨
V
V
DD
DD
©
TVTEMP
where:
TC VTEMP
ANGLE CALCULATION
To calculate angle from the output of the AMR device, use the
trigonometric function arctangent2. The arctangent2 function
is a standard arctangent function with additional quadrant
information to extend the output from the magnetic angle range
of −90° to +90° to the magnetic angle range of −180° to +180°.
Because of the sensing range of AMR technology, this
calculated magnetic angle repeats over each pole of the magnet.
For a simple dipole magnet, the following equation reports
absolute angle over 180° mechanical:
TVTEMP is the calculated temperature (°C) from the VTEMP
output voltage.
VTEMP is the VTEMP output voltage during operation.
VDD is the supply voltage.
VCAL is the VTEMP output voltage during calibration at a
controlled temperature.
TCAL is the controlled temperature during calibration.
TCO is the temperature coefficient of the internal circuit; see the
Specifications section for the exact value.
VSIN
arctan(
2
)
Gain Control Mode
VCOS
D
Gain control (GC) enable mode can be activated by switching
the GC pin to the VDD pin. In this mode, the AMR bridge
sensor amplitude outputs are compensated to reduce
temperature variation. This results in higher and controlled
output voltage levels, boosting system dynamic range and
easing the system design task. If the GC pin is left floating, a
weak pull-up resistor ensures that the GC mode is enabled as a
default condition. The GC mode can also be used as a sensor
self diagnostic by comparing the sine and cosine amplitude
outputs when enabled and disabled, such as radius check. In the
event that the radius does not change, it indicates a gross failure
in the IC.
CONNECTION TO ECU
Because of the limited driving capability of the ADA4571
output, minimize the length of printed circuit board (PCB)
traces between the ADA4571 and other IC. Shielding of the
signal lines is recommended. Match the load capacitors and
resistors for best angular accuracy. Add bandwidth limitation
filters related to the sampling frequency of the system in front
of the ADC inputs to reduce noise bandwidth.
In Figure 29, the load resistors on VCOS and VSIN are
representing the input load of the filter and the ADC. The
processor may be used for arctan and offset calculations, offset
storage, and additional calibration.
Power-Down Mode
Power-down mode can be activated by switching the PD pin to
the VDD pin. Within this mode, the device shuts down and its
output pins are set to high impedance to avoid current
consumption across the load resistors. The VTEMP output is
connected to ground through a pull-down resistor. Power-down
mode can be entered with GC = VDD or GC = GND. An internal
pull-down resistor ensures that the device remains active if the
PD pin is left floating.
VTEMP Output Pin
A proportional to absolute temperature circuit provides a
voltage output at the VTEMP pin for temperature monitoring
or temperature calibration purposes. The output voltage is
ratiometric to the supply voltage enabling the interface with an
ADC that uses the supply voltage to generate the reference
voltage. This pin must be left open when not in use.
Rev. 0 | Page 16 of 21
Data Sheet
ADA4571
VDD
R
C
LO4
LO4
VDD
VTEMP
GC
ADA4571
TEMPERATURE SENSOR
BRIDGE DRIVER
VDD
+
–
VSIN
Ȉꢈǻ
ADC
EMI
FILTER
DRIVER
G = 40
R
C
LO1
LO1
AMR BRIDGE
SENSORS
MICROPROCESSOR
BIAS
OSCILLATOR
FAULT DETECTION
+
EMI
FILTER
VCOS
Ȉꢈǻ
ADC
DRIVER
G = 40
–
R
C
LO2
LO2
GND
GND
PD
R
C
LO3
LO3
Figure 29. Typical Application Diagram with Separate Processor and Data Conversion
Offset of Signal Outputs
Power Consumption
The single-ended output signals are referenced to VDD/2
Worst case quiescent power occurs when the supply current
runs at its specified maximum of 7 mA and the ADA4571 is run
at the maximum VDD of 5.5 V, giving a worst case quiescent
power of 38.5 mW.
generated internally on-chip. Offsets originate from matching
inaccuracies and other imperfections during the production
process. For tight tolerances, it is required to match the external
loads for VSIN and VCOS to each other. For ESD and EMC
protection, the outputs contain a series resistance of 50 Ω. The
influence of this series resistance is minimized with a large
output load resistance.
The power consumption is dependent on VDD, temperature,
load resistance (RL), load capacitance (CL), and frequency of the
rotating magnetic field. It is recommended to refer RL and CL to
ground. The output voltages are protected against short circuit
to the VDD pin or ground by current limitation within the
given time duration. Placing the device 180° rotated into the
socket may lead to damages if the supply current is not limited
to 100 mA.
Signal Dependence on Air Gap Distance
The IC measures the direction of the external magnetic field
within its x-y plane. The result is widely independent of the
field strength as long as it is above the specified minimum value
of 25 kA/m. Within a homogeneous field in x-y direction, the
result is independent of its placement in z direction (air gap).
The nominal z distance of the internal x-y plane to the top
surface of the plastic package is 0.400 mm.
Rev. 0 | Page 17 of 21
ADA4571
Data Sheet
MECHANICAL TOLERANCES DIAGRAMS
5.00
4.90
4.80
A
2.50
2.45
2.40
SENSING ELEMENT
CENTER
B
LEAD TIPS
3.10
3.00
2.90
2.00
1.95
1.90
5
4
8
1
NOTE 4
4.00
6.20
6.00
5.80
0.50 C B
3.90
3.80
2° MAX
NOTE 2
0.854
0.25 C A
NOTES 3, 6, 7
0.10 C
0.487
0.437
0.387
1.27
C
SEATING PLANE
NOTES 5, 6
0.25 M C A B
ALL LEADS
NOTES
1. DIMENSIONS ARE IN MILLIMETERS.
2. MAXIMUM SENSOR ROTATION.
3. THIS DIMENSION AND TRUE POSITION SPECIFY THE LOCATION OF THE CENTER
OF THE SENSING ELEMENT WITH RESPECT TO THE CENTER OF THE PACKAGE.
THE CENTER OF THE SENSING ELEMENT IS ALIGNED WITH THE EDGES OF
LEAD 2 AND LEAD 7.
4. THE CENTER OF THE SENSING ELEMENT IS ALIGNED WITH THE CENTER LINE
OF THE PACKAGE (DATUM B).
5. THE LEAD WIDTH DIMENSION IS TOLERANCED MORE TIGHTLY THAN ON
THE R8 PACKAGE OUTLINE DRAWING. THIS DIMENSION IS MEASURED AT
THE FOOT OF THE LEAD (NO FLASH, BURRS).
6. DOES NOT INCLUDE MOLD FLASH, DAMBAR PROTRUSIONS, OR BURRS.
7. MOLD BODY WIDTH AND LENGTH DIMENSIONS DO NOT INCLUDE MOLD FLASH,
OFFSETS, OR MOLD GATE PROTRUSIONS.
8. REFER TO THE R8 PACKAGE OUTLINE DRAWING FOR DIMENSIONS NOT SHOWN HERE.
Figure 30. Mechanical Drawing of the ADA4571
0.475
0.400
0.325
AMR SENSING ELEMENT
1.400
1.250
1.100
0.10 C
C
SEATING PLANE
Figure 31. Cross Sectional View of the ADA4571
Rev. 0 | Page 18 of 21
Data Sheet
ADA4571
V
SIN
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
DIAGNOSTICS
+150°C
+125°C
+25°C
–40°C
Radius Calculation
The VSIN and VCOS outputs can be used to calculate a radius
value. These outputs have a fixed 90° phase relationship and
therefore the calculated radius value remains in a predictable,
predetermined range that varies with the temperature of the
device independent of the current magnetic field direction. This
radius, VRAD, can be used to validate the VSIN and VCOS readings
in the ECU. When the calculated radius is no longer within the
acceptable bounds, a fault may occur in the system. To calculate
radius, use the following formula:
V
RAD
V
COS
V
COS
V
VDD
2
VRAD
(VSIN
ꢀ
DD )2 ꢁ (VCOS
ꢀ
)
2
2
It is important to perform offset calibration before calculating
the radius.
0
V
MAGNITUDE (%V
GC OFF
)
DD
COS
Figure 32 shows the allowable radius values when GC mode is
enabled and Figure 33 shows the allowable radius values when
GC mode is disabled. The maximum and minimum VRAD values
are calculated based on the allowable amplitude range for VSIN
and VCOS, over the entire operating temperature of the device as
specified in the Specifications section. This range is represented
by the shaded region in Figure 32 and Figure 33.
Figure 33. GC Off Radius Values
Monitoring of the VTEMP pin can allow an even tighter range
for radius length at the known temperature. See the
Specifications section and the Typical Performance
Characteristics section for exact values and output amplitude
specifications at each temperature.
Typical VRAD values for −40°C, +25°C, +125°C, and +150°C are
indicated as well.
Broken Bond Wire Detection
V
SIN
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
The ADA4571 includes circuitry to detect broken bond wire
conditions between the AMR sensor and the instrumentation
amplifier. The detection circuitry consists of current sources
and window comparators placed on the signal connections
between the AMR sensor and the ASIC. The purpose of the
current sources is to pull the signal node outside of the normal
operating region in the event of an open bond wire between the
AMR sensor and the ASIC. The purpose of the window
comparators is to detect when the signal from the AMR sensor
is outside of the normal operating region. When the comparators
detect that the signal nodes are outside the normal operating
region, the circuit pulls the VSIN and/or VCOS node to ground
to indicate the fault to the host controller.
+150°C
+125°C
+25°C
–40°C
V
RAD
V
COS
V
COS
In addition to the active circuitry, there are applications
recommendations, such as the utilization of pull-up and pull-
down resistors, which detect broken bond wires by pulling
nodes outside of the defined operating regions. A broken bond
wire at VTEMP, VCOS, and VSIN interrupts the corresponding
outputs. To ensure that the output enters into a known state if
there is a broken bond wire on these pins, connect a 200 kΩ
pull-down resistor at these pins. Pulling these nodes outside of
the normal operating region signals a fault to the host
controller.
0
V
MAGNITUDE (%V
GC ON
)
DD
COS
Figure 32. GC On Radius Values
Rev. 0 | Page 19 of 21
ADA4571
Data Sheet
Short-Circuit Condition to GND or VDD
Short-Circuit Between Sine and Cosine Sensor Outputs
In the event of a short-circuit condition, the output voltages are
pulled to the GND or VDD pin.
In the event of a short-circuit between sensor outputs, the IC
output voltages are tied to the output common-mode voltage. A
gross angular error is detected in the microcontroller.
100%
SHORT-CIRCUIT DIAGNOSTIC BAND (HIGH)
93%
LINEAR REGION
7%
0%
SHORT-CIRCUIT DIAGNOSTIC BAND (LOW)
Figure 34. Output Span Classification During Short-Circuit Diagnostic Condition
Table 7. Diagnostic Cases
Fault Description
Output Conditions
Alert
Broken Bond Wire Between the
Internal MR Sensor and the ASIC
Broken bond wire detection is activated; the
broken channel(s), VSIN or VCOS, are pulled to
ground
Diagnostic region violation
Broken Bond Wire at the PD Pin
Broken Bond Wire at the GC Pin
Output Short-Circuit to GND
Output Short-Circuit to VDD
Device remains functional
No alert
Gain control is activated
Possible change in output amplitude
Diagnostic region violation
Diagnostic region violation
Shorted channel is pulled to ground
Shorted channel is pulled to VDD
Rev. 0 | Page 20 of 21
Data Sheet
ADA4571
OUTLINE DIMENSIONS
5.00 (0.1968)
4.80 (0.1890)
8
1
5
4
6.20 (0.2441)
5.80 (0.2284)
4.00 (0.1574)
3.80 (0.1497)
0.50 (0.0196)
0.25 (0.0099)
1.27 (0.0500)
BSC
45°
1.75 (0.0688)
1.35 (0.0532)
0.25 (0.0098)
0.10 (0.0040)
8°
0°
0.51 (0.0201)
0.31 (0.0122)
COPLANARITY
0.10
1.27 (0.0500)
0.40 (0.0157)
0.25 (0.0098)
0.17 (0.0067)
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MS-012-AA
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.
Figure 35. 8-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-8)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model1, 2
Temperature Range
−40°C to +150°C
Package Description
Package Option
ADA4571WHRZ-R7
ADA4571BRZ
8-Lead SOIC_N, 7”Tape and Reel
8-Lead SOIC_N
R-8
R-8
R-8
R-8
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
ADA4571BRZ-RL
ADA4571BRZ-R7
8-Lead SOIC_N, 13”Tape and Reel
8-Lead SOIC_N, 7”Tape and Reel
1 Z = RoHS Compliant Part.
2 W = Qualified for Automotive Applications.
AUTOMOTIVE PRODUCTS
The ADA4571WHRZ model is available with controlled manufacturing to support the quality and reliability requirements of automotive
applications. Note that this automotive model may have specifications that differ from the commercial models; therefore, designers
should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in
automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to
obtain the specific Automotive Reliability reports for these models.
©2014 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D12514-0-10/14(0)
Rev. 0 | Page 21 of 21
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