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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