Integrated magnetoresistive (AMR) angle sensor and signal conditioner

October 27, 2014 // By Graham Prophet
Analog Devices has posted details of the ADA4571, an anisotropic magnetoresistive (AMR) sensor with integrated signal conditioning amplifiers and ADC drivers. The device produces two analogue outputs that indicate the angular position of the surrounding magnetic field.

The ADA4571 consists of two dice 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. Use the part, ADI suggests, for absolute position measurement (linear and angle); brushless dc motor control and positioning; actuator control and positioning; contactless angular measurement and detection; and magnetic angular position sensing.

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.

Analog Devices;

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