AMR sensor with integrated signal regulating amplifier and ADC driver

ADI's ADA4571-2 is a 2-channel anisotropic reluctance (AMR) sensor with an integrated signal conditioning amplifier and modular (ADC) driver. The device produces two analog outputs indicating the angular position of the surrounding magnetic field. Each channel consists of two chips in a package: an AMR sensor and a variable gain instrumentation amplifier.

The ADA4571-2 provides clean, amplified cosine and sine output signals related to the Angle of the rotating magnetic field. The output voltage range is proportional to the supply voltage. Each sensing channel consists of two independent Wyeth Bridges at 45° relative angles to each other. A rotating magnetic field parallel to the IC packaging plane provides two sinusoidal output signals at a frequency twice the Angle α between the sensor and the direction of the magnetic field. In a uniform field parallel to the IC packaging plane, the output signal is independent of the air gap between the sensor and the magnet.

The EVAL-ADA4571-2 has an onboard 5 V regulator, a 6 channel synchronous sampling ADC, and jumpers for enabling temperature compensation and outage modes in the ADA4571-2. The motherboard also has test points for the six outputs of the device and unfilled coaxial connectors. The EVAL-ADA4571-2 Installs the ADA4571-2 in a shaft-end magnet configuration. The evaluation kit consists of an ADA4571-2 motherboard, a magnetic actuator on a manually rotating stand, a USB interface, and an SDP-S controller board

Features

● Non-contact Angle measurement
● Measure the direction of the magnetic field rather than its strength
● Minimal sensitivity to air gap changes
● Large working distance
● Excellent accuracy, even for weakly saturated fields
● Minimum thermal drift and lifetime drift
● The lag is negligible
● Single chip solution
● High precision, 2 channel, isolated AMR Angle sensor for redundant systems
● The Angle range is 0° to 180°
● The typical Angle error is 0.1°
● Each channel simulates the sine and cosine output
● Proportional output voltage
● Low heat and service life drift
● Has the capability of successive approximation register (SAR) ADC or trigonometric ADC driver
● Magnetic resistance (MR) bridge temperature compensation mode
● Temperature range: -40°C to +150°C
● The supply voltage (VDD) is from 3 V to 5.5 V
● Minimum phase delay
● Use 16 lead SOIC package

Applications

● Permanent magnet synchronous motor (PMSM) control and positioning
● Non-contact Angle measurement and detection
● Magnetic angular position sensing
● Passed the automotive application certification