Based on the Anisotropic MagnetoResistive (AMR) effect, the KMI25/2 and the KMI25/4 detect the rotational speed of target wheels. The KMI25/2 is used with active target wheels (multipole encoders) and the KMI25/4 is used with passive target wheels (ferromagnetic gear wheels). This design delivers secure speed information over a wide range of speed, air gap and temperature. It delivers the speed information via a current