AMR sensor integrates signal-conditioning amplifiers and ADC drivers

The Analog Devices ADA4571 anisotropic magnetoresistive (AMR) sensor is now available from Farnell element14. The sensor integrates signal conditioning amplifiers and ADC drivers, producing two analogue 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 (nominal G = 40) instrumentation amplifier. This device 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. Available in an 8-lead SOIC package, the sensor contains two Wheatstone bridges, mounted at a relative angle of 45° to each other. A rotating magnetic field in the x-y sensor plane delivers two sinusoidal output signals with the double frequency of the angle (a) 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). Applications include 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.