ADA4571: Integrated AMR Angle Sensor and Signal Conditioner Data Sheet0 pages

FEATURES

FUNCTIONAL BLOCK DIAGRAM
VDD

High precision 180° angle sensor
Maximum angular error of 0.5°
Analog sine and cosine outputs
Ratiometric output voltages
Low thermal and lifetime drift
SAR or Σ-Δ analog-to-digital converter (ADC) drive capable
Magnetoresistive (MR) bridge temperature compensation mode
Temperature range: −40°C to +150°C
EMI resistant
Fault diagnostics
VDD from 2.7 V to 5.5 V
Minimum phase delay
Qualified for automotive applications
Available in an 8-lead SOIC package

ADA4571

TEMPERATURE SENSOR

GC

BRIDGE DRIVER

+

EMI
FILTER

AMR BRIDGE
SENSORS

BIAS

G = 40

Absolute position measurement (linear and angle)
Brushless dc motor control and positioning
Actuator control and positioning
Contactless angular measurement and detection
Magnetic angular position sensing

VSIN

DRIVER

–

OSCILLATOR

EMI
FILTER

APPLICATIONS

VTEMP

FAULT DETECTION

+
–

G = 40

GND

GND

DRIVER

VCOS

PD

12514-001

Data Sheet

Integrated AMR Angle Sensor and Signal
Conditioner
ADA4571

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.
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.
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).

COMPANION PRODUCTS
ADCs: AD7265, AD7266, AD7866, AD7902
Microconverter: ADuCM360
Current Sense Amplifier: AD8418A
Voltage Regulator Design Tool: ADIsimPower
Additional companion products on the ADA4571 product page

PRODUCT HIGHLIGHTS
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Contactless angular measurement.
Measures magnetic field direction rather than field intensity.
Minimum sensitivity to air gap variations.
Large working distance.
Excellent accuracy, even for weak saturation fields.
Minimal thermal and lifetime drift.
Negligible hysteresis.
Single chip solution.

The ADA4571 is available in an 8-lead SOIC package.

Rev. 0

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