ADA4571 Integrated AMR Angle Sensor and Signal Conditioner

Integrated AMR Angle Sensor and Signal Conditioner Data Sheet ADA4571 FEATURES FUNCTIONAL BLOCK DIAGRAM VDD High precision 180° angle sensor Maximum angular error of 0.5° ADA4571 Analog sine and cosine outputs TEMPERATURE SENSOR VTEMP Ratiometric output voltages BRIDGE DRIVER GC 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 + G = 40 DRIVER VSIN EMI resistant FILTER – Fault diagnostics VDD from 2.7 V to 5.5 V AMR BRIDGE BIAS OSCILLATOR FAULT DETECTION Minimum phase delay SENSORS Qualified for automotive applications Available in an 8-lead SOIC package EMI + FILTER G = 40 DRIVER VCOS 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 Figure 1. Magnetic angular position sensing GENERAL DESCRIPTION The ADA4571 is an anisotropic magnetoresistive (AMR) sensor COMPANION PRODUCTS with integrated signal conditioning amplifiers and ADC drivers. ADCs: AD7265, AD7266, AD7866, AD7902 The ADA4571 produces two analog outputs that indicate the Microconverter: ADuCM360 angular position of the surrounding magnetic field. Current Sense Amplifier: AD8418A The ADA4571 consists of two die within one package, an AMR Voltage Regulator Design Tool: ADIsimPower sensor, and a fixed gain (G = 40 nominally) instrumentation Additional companion products on the ADA4571 product page amplifier. The ADA4571 delivers clean and amplified cosine PRODUCT HIGHLIGHTS and sine output signals related to the angle of a rotating magnetic field. The output voltage range is ratiometric to the 1. Contactless angular measurement. supply voltage. 2. Measures magnetic field direction rather than field intensity. 3. Minimum sensitivity to air gap variations. The sensor contains two Wheatstone bridges, at a relative angle 4. Large working distance. of 45° to one another. A rotating magnetic field in the x-y 5. Excellent accuracy, even for weak saturation fields. sensor plane delivers two sinusoidal output signals with the 6. Minimal thermal and lifetime drift. double frequency of the angle (α) between sensor and magnetic 7. Negligible hysteresis. field direction. Within a homogeneous field in the x-y plane, 8. Single chip solution. the output signals are independent of the physical placement in the z direction (air gap). The ADA4571 is available in an 8-lead SOIC package. Rev. 0 Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 781.329.4700 ©2014 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 12514-001

ADA4571 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Pin Configuration and Descriptions ...............................................8 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................9 Functional Block Diagram .............................................................. 1 Terminology .................................................................................... 13 General Description ......................................................................... 1 Theory of Operation ...................................................................... 14 Companion Products ....................................................................... 1 Application Information ................................................................ 16 Product Highlights ........................................................................... 1 Angle Calculation ....................................................................... 16 Revision History ............................................................................... 2 Connection to ECU ................................................................... 16 Specifications ..................................................................................... 3 Mechanical Tolerances Diagrams ............................................ 18 Magnetic Characteristics ............................................................. 3 Diagnostics .................................................................................. 19 Electrical Characteristics ............................................................. 3 Outline Dimensions ....................................................................... 21 Absolute Maximum Ratings ............................................................ 7 Ordering Guide .......................................................................... 21 Thermal Resistance ...................................................................... 7 Automotive Products ................................................................. 21 ESD Caution .................................................................................. 7 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 Test Conditions/Comments Magnetic Field Strength, HEXT 25 kA/m 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 50,000 rpm Frequency Reference Position Error ±50 µm 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 Angle Error ±2 Degrees Reference position for angle Φ = 0° is parallel to the straight connection line of Pin 2 and Pin 7 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 0 180 Degrees Uncorrected Angular Error1 αUNCORR TA = −40°C ±5 Degrees TA = 25°C ±5 Degrees TA = 150°C ±5 Degrees Single Point Calibration Angular αCAL TA = −40°C to +150°C, GC = GND ±0.7 Degrees Error2, 3 TA = −40°C to +150°C, GC = VDD ±0.7 Degrees Dynamic Angular Error4 αDYNAMIC TA = −40°C to +150°C, rotation frequency = ±0.1 ±0.5 Degrees 2000 rpm OUTPUT PARAMETERS Amplitude VAMP GC = GND TA = −40°C 63 75 % VDD TA = 25°C 41 53 % VDD TA = 125°C 21 33 % VDD TA = 150°C 18 30 % VDD GC = VDD TA = −40°C 56 77 % VDD TA = 25°C 52 72 % VDD TA = 125°C 38 57 % VDD TA = 150°C 35 55 % VDD Output Voltage Range VO_SWING VSIN and VCOS, normal operation 7 93 % VDD Output Voltage Low VOL VSIN or VCOS, broken bond wire detected 5 % VDD Output Referred Offset Voltage VOFFSET GC = VDD 3.75 % VDD GC = GND 3.75 % VDD Amplitude Synchronism Error5 k −1 +1 % peak Delay Time tDEL Rotation frequency = 30,000 rpm 2 µs Phase Error6 ΦERR Rotation frequency = 30,000 rpm 0.8 Degrees Orthogonality Error3 OE 0.05 Degrees Output Noise VNOISE Bandwidth (BW) = 80 kHz, referred to 500 µV rms output (RTO) Output Series Resistance RO Normal operation, PD = GND 60 Ω PD = VDD 63 kΩ Output −3 dB Cutoff Frequency3 f−3dB Amplifier BW, CL = 10 pF 100 kHz Rev. 0 | Page 3 of 21

ADA4571 Data Sheet Parameter Symbol Test Conditions/Comments Min Typ Max Unit Power Supply Rejection3 PSRR Measured as output variation from VDD/2, 80 dB VDD = 2.7 V to 5.5 V, RL = 200 kΩ to GND, GC = GND or VDD Output Short-Circuit Current ISC Short to GND per pin (VSIN, VCOS) 15 20 mA Short to VDD per pin (VSIN, VCOS) −15 −18 mA Sensitivity SEN α1 = 0°, α2 = 135°, TA = 25°C 52 mV/° POWER SUPPLY Supply Voltage VDD 2.7 5.5 V Quiescent Supply Current ISY PD = GND, GC = GND, no load 3.5 4.5 6.5 mA PD = GND, GC = VDD, no load 7 mA PD = VDD, no load 15 µA Power-Up Time tPWRUP To 98% of desired output level after VDD was 150 µs reached To 98% of desired output level after PD cycling 100 µs DIGITAL INPUTS Input Bias Current (GC) IB_GC For GC mode control pin, GC = GND 30 µA For GC mode control pin, GC = VDD 3 µA Input Bias Current (PD) IB_PD For PD pin, PD = GND 3 µA For PD pin, PD = VDD 30 µA Input Voltage (GC and PD) High VIH 1.4 V Low VIL 0.35 V TEMPERATURE SENSOR Error Over Temperature TERR 5 °C Temperature Voltage Range TRANGE TA = −40°C to +150°C 0 82 % VDD Temperature Coefficient TCO 3.173 mV/V/°C VTEMP Output Voltage TA = 25°C 18 40 % VDD VTEMP Output Impedance Buffered output 50 Ω VTEMP Load Capacitance Optional load capacitance 0 22 nF VTEMP Short-Circuit Current ISC_VTEMP Short-circuit to VDD or GND 2 mA LOAD CAPACITOR External Load Capacitance CL Between VSIN to GND and VCOS to GND; 10 nF solder close to package 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 0 180 Degrees Uncorrected Angular Error1 αUNCORR TA = −40°C ±3 Degrees TA = 25°C ±3 Degrees TA = 125°C ±4 Degrees Single Point Calibration Angular αCAL TA = −40°C to +125°C, GC = GND ±0.5 Degrees Error2, 3 TA = −40°C to +125°C, GC = VDD ±0.5 Degrees Dynamic Angular Error4 αDYNAMIC TA = −40°C to +125°C, rotation frequency = 0.1 ±0.4 Degrees 2000 rpm Angular Inaccuracy3, 5 ∆α After end of line (EOL) calibration for offset 0.05 Degrees voltage error and amplitude synchronism at TA = −40°C to +125°C (only 180° range) OUTPUT PARAMETERS Amplitude VAMP GC = GND TA = −40°C 63 75 % VDD TA = 25°C 41 53 % VDD TA = 125°C 21 33 % VDD GC = VDD TA = −40°C 56 77 % VDD TA = 25°C 52 72 % VDD TA = 125°C 38 57 % VDD Output Voltage Range VO_SWING VSIN and VCOS, normal operation 7 93 % VDD Output Voltage Low VOL VSIN or VCOS, broken bond wire detected 3.75 % VDD Output Referred Offset Voltage VOFFSET GC = VDD 3.75 % VDD GC = GND 3.75 % VDD Amplitude Synchronism Error6 k −0.75 +0.75 % peak Delay Time tDEL Rotation frequency = 30,000 rpm 2 µs Phase Error7 ΦERR Rotation frequency = 30,000 rpm 0.8 Degrees Orthogonality Error3 OE 0.05 Degrees Output Noise VNOISE BW = 80 kHz, RTO 500 µV rms Output Series Resistance RO Normal operation, PD = GND 50 Ω PD = VDD 63 kΩ Output −3 dB Cutoff Frequency3 f−3dB Amplifier BW, CL = 10 pF 100 kHz Power Supply Rejection3 PSRR Measured as output variation from VDD/2, 80 dB VDD = 2.7 V to 5.5 V, RL = 200 kΩ to GND, GC = GND or VDD Output Short-Circuit Current ISC Short to GND per pin (VSIN, VCOS) 15 20 mA Short to VDD per pin (VSIN, VCOS) −15 −18 mA Sensitivity SEN α = 0° and 135°, TA = 25°C 52 mV/° POWER SUPPLY Supply Voltage VDD 2.7 5.5 V Quiescent Supply Current ISY PD = GND, GC = GND, no load 3.5 4.5 6 mA PD = GND, GC = VDD 6.5 mA PD = VDD, no load 12.5 µA Power-Up Time tPWRUP To 98% of desired output level after VDD was 150 µs 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 For GC mode control pin, GC = GND 30 µA For GC mode control pin, GC = VDD 3 µA Input Bias Current (PD) IB_PD For PD pin, PD = GND 3 µA For PD pin, PD = VDD 30 µA Input Voltage (GC and PD) High VIH 1.4 V Low VIL 0.35 V TEMPERATURE SENSOR Error Over Temperature TERR 5 °C Temperature Voltage Range TRANGE TA = −40°C to +125°C 0 69 % VDD Temperature Coefficient TCO 3.173 mV/V/°C VTEMP Output Voltage TA = 25°C 18 40 % VDD VTEMP Output Impedance Buffered output 50 Ω VTEMP Load Capacitance Optional load capacitance 0 22 nF VTEMP Short-Circuit Current ISC_VTEMP Short-circuit to VDD or GND 2 mA LOAD CAPACITOR External Load Capacitance CL Between VSIN to GND and VCOS to GND; 10 nF solder close to package 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 Parameter Rating θJA is specified for the worst case conditions, that is, a device Operating Temperature −40°C to +150°C soldered in a circuit board for surface-mount packages. Storage Temperature −65°C to +150°C Table 5. Thermal Resistance Supply Voltage (VDD)1 −0.3 V to +6 V Output Short-Circuit Duration to GND or VDD Indefinite Package Type θJA Unit VTEMP Short-Circuit to GND or VDD Indefinite 8-Lead SOIC 120 °C/W ESD Human Body Model (HBM)2 4000 V ESD CAUTION Machine Model (MM)3 300 V Charge Device Model (CDM)4 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 1 8 PD VCOS 2 ADA4571 7 VDD TOP VIEW GND 3 (Not to Scale) 6 GND VSIN 4 5 VTEMP Figure 2. Pin Configuration Table 6. Pin Function Descriptions Pin No. Mnemonic Description 1 GC Gain Control Mode Enable 2 VCOS Analog Cosine Output 3 GND Ground 4 VSIN Analog Sine Output 5 VTEMP Temperature Output 6 GND Ground 7 VDD Supply Pin 8 PD Power-Down Pin, Active High Rev. 0 | Page 8 of 21 12514-002

Data Sheet ADA4571 TYPICAL PERFORMANCE CHARACTERISTICS 5 40 –40°C +25°C 35 +125°C +150°C 4 30 25 3 20 2 15 10 1 5 0 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 RELATIVE MECHANICAL ANGLE (Degrees) DYNAMIC ANGULAR ERROR (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 –40°C +25°C 30 +125°C +150°C 0.1 25 20 0 15 –0.1 10 5 –0.2 0 90 180 270 360 0 0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 MECHANICAL ANGLE (Degrees) DYNAMIC ANGULAR ERROR (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 –40°C –40°C +25°C +25°C 35 +125°C +125°C +150°C 30 +150°C 30 25 25 20 20 15 15 10 10 5 5 0 0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 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) 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 COUNT (%) ERROR (Degrees) OUTPUT AMPLITUDE (V) 12514-012 12514-011 12514-010 COUNT (%) COUNT (%) COUNT (%) 12514-015 12514-014 12514-013

ADA4571 Data Sheet 40 35 –40°C –40°C +25°C +25°C 35 +125°C 30 +125°C +150°C +150°C 30 25 25 20 20 15 15 10 10 5 5 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 35 +125°C +150°C 1.0 30 0.8 25 20 0.6 15 0.4 10 0.2 5 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 –40°C +25°C 30 +125°C +150°C 1.0 25 0.8 20 0.6 15 0.4 10 5 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 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 COUNT (%) COUNT (%) COUNT (%) 12514-018 12514-017 12514-016 ERROR (Degrees) ERROR (Degrees) COUNT (%) 12514-019 12514-021 12514-020

Data Sheet ADA4571 1.2 5.8 GC OFF (mA) GC ON (mA) 1.0 5.6 0.8 5.4 0.6 5.2 0.4 5.0 0.2 4.8 0 4.6 –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 4.6 GC OFF (mA) GC ON (mA) 1.0 4.4 0.8 4.2 0.6 4.0 0.4 3.8 0.2 0 3.6 –40 0 40 80 120 –40 0 40 80 120 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 5V 3V 8 6 6 5 4 4 2 3 0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 –40 0 40 80 120 VDD (V) TEMPERATURE (°C) Figure 17. Supply Current (I ) vs. Voltage (V ), T = 25°C Figure 20. Power-Down Current (IPD) vs. Temperature SY DD Rev. 0 | Page 11 of 21 ISY (mA) ERROR (Degrees) ERROR (Degrees) 12514-023 12514-022 12514-024 IPD (µA) ISY (mA) ISY (mA) 12514-027 12514-026 12514-025

ADA4571 Data Sheet 100 100 VOUT p-p GC OFF 90 VOUT p-p GC ON 90 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 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 0 18 –0.1 16 –0.2 14 –0.3 12 –0.4 10 –0.5 8 –0.6 6 –0.7 4 –0.8 2 –0.9 ERROR –40°C ERROR +25°C ERROR +150°C 0 –1.0 –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 COUNT (%) VTEMP (%VDD) 12514-028 12514-029 ANGULAR ERROR DELAY (Degrees) VOUT (V p-p %VDD) 12514-030 12514-031

Data Sheet ADA4571 TERMINOLOGY Reference Position Error Uncorrected Angular Error The reference position error is the absolute mounting position The uncorrected angular error is defined as the maximum deviation of the sensor from its nominal placement. The deviation from an ideal angle reading, when calculating the reference position for Y = 0 µm is the straight connection line of angle from VSIN and VCOS without offset calibration. Pin 2 and Pin 7. The X = 0 µm position is referred to the middle Single Point Calibration Angular Error distance of the package top. The position accuracies are within The single point calibration angular error is defined as the a precision of ±0.05 mm (±50 µm) in both the X and Y maximum deviation from an ideal angle reading, when direction. calculating the angle from VSIN and VCOS after an initial Reference Angle Error calibration for offset voltage at TA = 25°C. The reference angle error is the absolute mounting rotation Dynamic Angular Error deviation of the sensor from its nominal placement. Marking The dynamic angular error is defined as the maximum the position for angle Φ= 0° position is referred parallel to the deviation from an ideal angle reading, when calculating the straight connection line of Pin 2 and Pin 7. angle from VSIN and VCOS while a continuous offset calibration is taken into account. GC 1 8 PD VCOS 2 7 VDD Phase Error GND 3 6 GND The phase error (ΦERR) is defined as the rotation frequency VSIN 4 5 VTEMP dependent error due to bandwidth limitation of the instrumen- tation amplifiers. VSIN and VCOS are impacted by the amplifier Figure 25. Bonding Arrangement and Sensor Alignment in Package propagation delay, referred to the actual angle direction of the Output Amplitude Synchronism Error rotating magnetic field. The typical characteristics value can be The output amplitude matching error (k) is defined as the used for a first-order compensation of this error on very high relationship between both output channel amplitudes at rotations per minute. For low rotational speed systems, this error continuously rotating magnetic excitation of the MR sensor component is negligible and no compensation is necessary. mathematically expressed as k = 100% × VSIN_P-P/VCOS_P-P Rev. 0 | Page 13 of 21 12514-006

ADA4571 Data Sheet THEORY OF OPERATION The ADA4571 is an AMR sensor with integrated signal Electromagnetic interference (EMI) filters at the sensor outputs conditioning amplifiers and ADC drivers. The ADA4571 and between the first and second stages reject unwanted noise produces two analog outputs, sine and cosine, which indicate and interference from appearing in the signal band. the angular position of the surrounding magnetic field. The architecture of the instrumentation amplifier consists of The AMR sensing element is designed and manufactured by precision, low noise, zero drift amplifiers that feature a proprietary Sensitec GmbH. 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 Figure 27 shows the sine channel, consisting of an AMR sensor chopping ripple suppression circuitry, which removes glitches element and the supporting functions for control, filtering, and other artifacts caused by chopping. buffering, and signal amplification. A reference voltage that is Offset voltage errors caused by common-mode voltage swings proportional to the supply voltage is generated and it controls and power supply variations are also corrected by the chopping the supply voltage of the sensor bridges. For noise and technique, resulting in a dc common-mode rejection ratio that electromagnetic compatibility (EMC) suppression purposes, the is greater than 150 dB. The amplifiers feature low broadband bridge supply is low-pass filtered. The bridge output voltages noise of 22 nV/√Hz and no 1/f noise component. These features are amplified by a constant factor (G = 40, GC mode disabled) are ideal for amplification of the low level AMR bridge signals and buffered. The single-ended outputs are biased around a for high precision sensing applications. common-mode voltage of VDD/2 and are capable of driving the In addition, extensive diagnostics are integrated on-chip to self inputs of an external ADC referenced to the supply voltage. check sensor and IC conditions. For optimum use of the ADC input range, the cosine and sine 1 8 output voltages track the supply voltage ensuring a ratiometric 2 ADA4571 7 configuration. To achieve high signal performance both output TOP VIEW 3 (Not to Scale) 6 signals are carefully matched in both amplitude and phase. The 4 5 amplifier bandwidth is sufficient to ensure low phase delay at maximum specified rotation speed. Figure 26. Direction of Homogeneous Magnetic Field for α = 0° VDD VDD VDD + – 62.7pF + VTEMP – – AMR BRIDGE 20pF VSIN + ADA4571 – + 62.7pF VDD/2 Figure 27. Detailed Internal Diagram of the ADA4571 Sine Channel Rev. 0 | Page 14 of 21 12514-004 12514-005

Data Sheet ADA4571 DIAGNOSTIC 93% V BAND DD VCOS VOFFSET V p-p LINEAR 50% VDD REGION VSIN 7% VDD DIAGNOSTIC BAND 0 90 180 270 360 MAGNETIC Figure 28. Typical Output Waveforms; Sine and Cosine vs. Magnetic Angle Rev. 0 | Page 15 of 21 12514-003

ADA4571 Data Sheet APPLICATIONS INFORMATION The integrated AMR sensor is designed for applications with a To achieve maximum accuracy from the VTEMP output separate processing IC or electronic control unit (ECU) containing voltage, perform an initial calibration at a known, controlled an ADC with references connected to the supply voltage. With temperature. Then, use the following equation to extract the ADC input resolution related to VDD in the same way as the temperature information: AMR sensor output, the system is inherently ratiometric and the V V signal dependency on supply voltage changes are minimized. TEMP – CAL – T T V V CAL CO DD DD T VTEMP ANGLE CALCULATION TC VTEMP To calculate angle from the output of the AMR device, use the where: trigonometric function arctangent2. The arctangent2 function TVTEMP is the calculated temperature (°C) from the VTEMP is a standard arctangent function with additional quadrant output voltage. information to extend the output from the magnetic angle range VTEMP is the VTEMP output voltage during operation. of −90° to +90° to the magnetic angle range of −180° to +180°. VDD is the supply voltage. Because of the sensing range of AMR technology, this VCAL is the VTEMP output voltage during calibration at a calculated magnetic angle repeats over each pole of the magnet. controlled temperature. For a simple dipole magnet, the following equation reports TCAL is the controlled temperature during calibration. absolute angle over 180° mechanical: TCO is the temperature coefficient of the internal circuit; see the Specifications section for the exact value. V arctan( SIN ) V Gain Control Mode COS 2 Gain control (GC) enable mode can be activated by switching CONNECTION TO ECU the GC pin to the VDD pin. In this mode, the AMR bridge Because of the limited driving capability of the ADA4571 sensor amplitude outputs are compensated to reduce output, minimize the length of printed circuit board (PCB) temperature variation. This results in higher and controlled traces between the ADA4571 and other IC. Shielding of the output voltage levels, boosting system dynamic range and signal lines is recommended. Match the load capacitors and easing the system design task. If the GC pin is left floating, a resistors for best angular accuracy. Add bandwidth limitation weak pull-up resistor ensures that the GC mode is enabled as a filters related to the sampling frequency of the system in front default condition. The GC mode can also be used as a sensor of the ADC inputs to reduce noise bandwidth. self diagnostic by comparing the sine and cosine amplitude outputs when enabled and disabled, such as radius check. In the In Figure 29, the load resistors on VCOS and VSIN are event that the radius does not change, it indicates a gross failure representing the input load of the filter and the ADC. The in the IC. 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 VTEMP Output Pin the VDD pin. Within this mode, the device shuts down and its A proportional to absolute temperature circuit provides a output pins are set to high impedance to avoid current voltage output at the VTEMP pin for temperature monitoring consumption across the load resistors. The VTEMP output is or temperature calibration purposes. The output voltage is connected to ground through a pull-down resistor. Power-down ratiometric to the supply voltage enabling the interface with an mode can be entered with GC = VDD or GC = GND. An internal ADC that uses the supply voltage to generate the reference pull-down resistor ensures that the device remains active if the voltage. This pin must be left open when not in use. PD pin is left floating. Rev. 0 | Page 16 of 21

Data Sheet ADA4571 VDD RLO4 CLO4 VDD VTEMP ADA4571 TEMPERATURE SENSOR GC VDD BRIDGE DRIVER EMI + VSIN G = 40 DRIVER FILTER ADC – RLO1 CLO1 AMR BRIDGE BIAS OSCILLATOR FAULT DETECTION MICROPROCESSOR SENSORS EMI + VCOS FILTER G = 40 DRIVER – ADC RLO2 CLO2 GND GND PD RLO3 CLO3 Figure 29. Typical Application Diagram with Separate Processor and Data Conversion Power Consumption Offset of Signal Outputs Worst case quiescent power occurs when the supply current The single-ended output signals are referenced to VDD/2 runs at its specified maximum of 7 mA and the ADA4571 is run generated internally on-chip. Offsets originate from matching at the maximum V of 5.5 V, giving a worst case quiescent inaccuracies and other imperfections during the production DD power of 38.5 mW. process. For tight tolerances, it is required to match the external loads for VSIN and VCOS to each other. For ESD and EMC The power consumption is dependent on VDD, temperature, protection, the outputs contain a series resistance of 50 Ω. The load resistance (RL), load capacitance (CL), and frequency of the influence of this series resistance is minimized with a large rotating magnetic field. It is recommended to refer RL and CL to output load resistance. ground. The output voltages are protected against short circuit to the VDD pin or ground by current limitation within the Signal Dependence on Air Gap Distance given time duration. Placing the device 180° rotated into the The IC measures the direction of the external magnetic field socket may lead to damages if the supply current is not limited within its x-y plane. The result is widely independent of the to 100 mA. 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 12514-007

ADA4571 Data Sheet MECHANICAL TOLERANCES DIAGRAMS 5.00 4.90 A 4.80 2.50 2.45 SENSING ELEMENT B LEAD TIPS CENTER 2.40 3.10 8 5 2.00 3.00 NOTE 4 1.95 2.90 4.00 1.90 6.20 0.50 C B 3.90 6.00 3.80 2° MAX 1 5.80 4 NOTE 2 0.854 0.25 C A NOTES 3, 6, 7 0.10 C 0.487 0.437 1.27 C SEATING PLANE 0.387 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 AMR SENSING ELEMENT 0.325 1.400 1.250 0.10 C 1.100 C SEATING PLANE Figure 31. Cross Sectional View of the ADA4571 Rev. 0 | Page 18 of 21 12514-035 12514-034

Data Sheet ADA4571 DIAGNOSTICS VSIN 100 +150°C 95 +125°C Radius Calculation 90 +25°C –40°C The VSIN and VCOS outputs can be used to calculate a radius 85 80 value. These outputs have a fixed 90° phase relationship and 75 therefore the calculated radius value remains in a predictable, 70 predetermined range that varies with the temperature of the 65 V 60 RAD device independent of the current magnetic field direction. This 55 radius, VRAD, can be used to validate the VSIN and VCOS readings 50 VCOS VCOS in the ECU. When the calculated radius is no longer within the 45 40 acceptable bounds, a fault may occur in the system. To calculate 35 radius, use the following formula: 30 25 V V 20 ( DD V V ) 2 ( DD V ) 2 15 RAD SIN COS 2 2 10 It is important to perform offset calibration before calculating 5 0 the radius. Figure 32 shows the allowable radius values when GC mode is VCOS MAGNITUDE (%VDD) enabled and Figure 33 shows the allowable radius values when GC OFF GC mode is disabled. The maximum and minimum VRAD values Figure 33. GC Off Radius Values are calculated based on the allowable amplitude range for VSIN Monitoring of the VTEMP pin can allow an even tighter range and VCOS, over the entire operating temperature of the device as for radius length at the known temperature. See the specified in the Specifications section. This range is represented Specifications section and the Typical Performance by the shaded region in Figure 32 and Figure 33. Characteristics section for exact values and output amplitude Typical VRAD values for −40°C, +25°C, +125°C, and +150°C are specifications at each temperature. indicated as well. Broken Bond Wire Detection VSIN 100 +150°C The ADA4571 includes circuitry to detect broken bond wire 95 +125°C conditions between the AMR sensor and the instrumentation 90 +25°C –40°C 85 amplifier. The detection circuitry consists of current sources 80 and window comparators placed on the signal connections 75 between the AMR sensor and the ASIC. The purpose of the 70 65 current sources is to pull the signal node outside of the normal 60 VRAD operating region in the event of an open bond wire between the 55 AMR sensor and the ASIC. The purpose of the window 50 V V COS COS 45 comparators is to detect when the signal from the AMR sensor 40 is outside of the normal operating region. When the comparators 35 30 detect that the signal nodes are outside the normal operating 25 region, the circuit pulls the VSIN and/or VCOS node to ground 20 to indicate the fault to the host controller. 15 10 In addition to the active circuitry, there are applications 5 recommendations, such as the utilization of pull-up and pull- 0 down resistors, which detect broken bond wires by pulling VCOS MAGNITUDE (%VDD) nodes outside of the defined operating regions. A broken bond GC ON wire at VTEMP, VCOS, and VSIN interrupts the corresponding Figure 32. GC On Radius Values 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. Rev. 0 | Page 19 of 21 VSIN MAGNITUDE (%VDD) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 V 80 SIN 85 90 95 100 12514-101 VSIN MAGNITUDE (%VDD) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 VSIN 85 90 95 100 12514-100

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 In the event of a short-circuit between sensor outputs, the IC pulled to the GND or VDD pin. 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% SHORT-CIRCUIT DIAGNOSTIC BAND (LOW) 0% Figure 34. Output Span Classification During Short-Circuit Diagnostic Condition Table 7. Diagnostic Cases Fault Description Output Conditions Alert Broken Bond Wire Between the Broken bond wire detection is activated; the Diagnostic region violation Internal MR Sensor and the ASIC broken channel(s), VSIN or VCOS, are pulled to ground Broken Bond Wire at the PD Pin Device remains functional No alert Broken Bond Wire at the GC Pin Gain control is activated Possible change in output amplitude Output Short-Circuit to GND Shorted channel is pulled to ground Diagnostic region violation Output Short-Circuit to VDD Shorted channel is pulled to VDD Diagnostic region violation Rev. 0 | Page 20 of 21 OUTPUT LEVEL 12514-009