Data Sheet

ADA4570

Integrated AMR Angle Sensor and Signal Conditioner with Differential Outputs

Rev. 0

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FEATURES

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Contactless angular measurement

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High precision 180° angle sensor

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Typical angular error of ±0.1°

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Low output noise of 850 μV rms

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Sine and cosine differential outputs

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Ratiometric analog voltage outputs

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Negligible hysteresis

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SAR or Σ-Δ ADC compatible

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Temperature compensated AMR bridge

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Industrial temperature range: −40°C to +125°C

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Automotive temperature range: −40°C to +150°C

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EMI resistant

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Fault diagnostics

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Minimal phase error of 0.85° at 30,000 rpm

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AEC-Q100 qualified for automotive applications

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Single chip solution

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Available in an 8-lead SOIC package

APPLICATIONS

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Absolute position measurement (linear and angle)

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Brushless dc motor control and positioning

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Actuator control and positioning

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Contactless angular measurement and detection

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Magnetic angular position sensing

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

GENERAL DESCRIPTION

The ADA4570 is an anisotropic magnetoresistive (AMR) sensor

with integrated signal conditioning amplifiers and analog-to-digi-

tal converter (ADC) drivers. The ADA4570 produces two differen-

tial analog outputs that indicate the angular position of the sur-

rounding magnetic field.

The ADA4570 consists of two die within one package, an AMR sen-

sor, and a fixed gain instrumentation amplifier. The ADA4570 de-

livers amplified differential cosine and sine output signals, with

respect to the angle, when the magnetic field is rotating in the

x-axis and the y-axis (x-y) plane. 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 complete rotation of a dipole magnet

produces two periods on the sinusoidal outputs. Therefore, the

magnetic angle (α) calculated from the SIN and COS differential

outputs represents the physical orientation of the magnet with

respect to the ADA4570 in the 0° to 180° measurement range.

Within a homogeneous field in the x-y plane, the output signals of

the ADA4570 are independent of the physical placement in the z

direction (air gap).

The ADA4570 is available in an 8-lead SOIC package.