Description

The ADA4571 is an anisotropic magnetoresistive (AMR) sensorwith integrated signal conditioning amplifiers and ADC drivers.The ADA4571 produces two analog outputs that indicate theangular position of the surrounding magnetic field.The ADA4571 consists of two die within one package, an AMRsensor, and a fixed gain (G = 40 nominally) instrumentationamplifier. The ADA4571 delivers clean and amplified cosineand sine output signals related to the angle of a rotatingmagnetic field. The output voltage range is ratiometric to thesupply voltage.The sensor contains two Wheatstone bridges, at a relative angleof 45° to one another. A rotating magnetic field in the x-ysensor plane delivers two sinusoidal output signals with thedouble frequency of the angle (α) between sensor and magneticfield direction. Within a homogeneous field in the x-y plane,the output signals are independent of the physical placement inthe z direction (air gap).The ADA4571 is available in an 8-lead SOIC package.Product Highlights Contactless angular measurement. Measures magnetic field direction rather than field intensity. Minimum sensitivity to air gap variations. Large working distance. Excellent accuracy, even for weak saturation fields. Minimal thermal and lifetime drift. Negligible hysteresis. Single chip solution.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