Unlike the Slide-By Displacement Sensing configuration, the head-on displacement configuration has a magnetic flux density that is either entirely positive or entirely negative, depending on whether the south or north pole of the magnet is closest to the sensor. As a result, the user can choose the sensors that are sensitive only to south field for this mechanical configuration. In cases where controlling the polarity of the magnet is not possible, the bipolar version (TMAG5253B) is chosen. The mapping of magnetic flux density to distance depends on various factors, such as the material and dimensions of the magnet. Figure 9-9 shows that the magnetic flux density is always positive as the magnet travels towards the sensor. Based on the magnetic field range, TMAG5253BA3 version with ±80mT full scale range is chosen. Figure 9-9 shows the output voltage of this sensor as the magnet travels from a distance of 10mm to a distance of 5mm towards the sensor. The DRV5056 Distance Measurement Tool calculates the expected magnetic flux density to distance mapping in a head-on configuration for different magnet specifications.