Magnetoresistive sensor for precision DC motor-control applications

Mouser is now stocking the ADA4571 Integrated AMR angle magnetic sensor and signal conditioner from Analog Devices. Consisting of both an anisotropic magneto-resistive sensor and a fixed gain instrumentation amplifier, the ADA4571 is one of the industry's highest-precision, highest-speed magnetic angle sensors that is four times more accurate, 60 percent faster, and 40 percent more power efficient than competing angle sensor solutions, says the company. The ADA4571 is specifically designed to measure the motor shaft position in brushless DC motors while reducing noise and increasing torque, while meeting new tighter environmental, noise and energy requirements. The ADA4571 provides direct, non-contact and wear-free angle measurements with a maximum low angular error of 0.5 degrees. A position feedback loop enables more effective torque and speed control in a wide range of brushless DC motor control applications. The ADA4571 supports high-speed motor operation up to 50,000 RPM, and the sensor's direct angle measurement helps reduce vibration and noise that can degrade DC motor performance. In rugged applications such as industrial servo motors, factory robotics, and electric power steering, the ADA4571's 2µs low-phase delay and torque control provides rapid closed-loop response which improves efficiency, lowers emissions, and reduces heat, resulting in an extended operating life for the system. The integrated AMR coupled with Analog Devices' precision signal conditioning technology allows the ADA4571 to maintain high-accuracy in noisy environments. The sensor's low temperature and lifetime-drift performance eliminates the need for calibration. The ADA4571 operates over 40C to +150C, and requires a 2.7V to 5.5V power supply that consumes just 6.5 mA of power. A sleep mode is useful in low power applications, and the sensor also supports advanced diagnostics for use in safety-critical applications. The ADI ADA4571 is available in an 8 lead SOIC package and is ideally suited for industrial applications that require both linear and angle absolute position measurement, including brushless DC motor control and positioning, actuator control and positioning, contactless angular measurement and detection, and magnetic angular position sensing, says the company.