FEATURES
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-∆ analog-to-digital converter (ADC) drive capable
Magnetoresistive (MR) bridge temperature compensation mode
Temperature range: −40°C to +150°C
EMI resistant
Fault diagnostics
V
DD
from 2.7 V to 5.5 V
Minimum phase delay
Qualified for automotive applications
Available in an 8-lead SOIC package
APPLICATIONS
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
FUNCTIONAL BLOCK DIAGRAM
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).
The
ADA4571 is available in an 8-lead SOIC package.
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
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.
8. Single chip solution.
ADA4571
EMI
FILTER
EMI
FILTER
+
G = 40
+
–
–
G = 40
DRIVER
DRIVER
AMR BRIDGE
SENSORS
TEMPERATURE SENSOR
BRIDGE DRIVER
BIAS OSCILLATOR
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