As shown to the right, the sensor IC can be used simply by locating a radially polarized disc magnet above or below the sensor with a gap.
With such a simple layout, you can create a system detecting absolute angles in a contactless manner.

• Compact absolute rotary encoder
• Compact input device (mode selector, control volume)
• Substitute for potentiometer
• Rotary switch

• Magnet : Neodymium magnet (Residual magnetic flux
  density: Br = 1250 mT)
  7.0 dia. ¡Á t2.0 mm (polarized in radial direction)
  
• Layout : Gap between magnet and sensor package:
  4 mm(This causes 30 mT to be applied to EM-3242.)
  *No eccentricity in magnet rotation.
  Sensor center aligned to rotation center.
• Peripheral circuit : A 0.1 mF bypass capacitor is connected between Vdd and Vss.
  Magnet rotation : Measured in 1¡ã increments up to 360¡ã