A novel readout technique for magnetoresistive sensors in automotive anti-lock braking systems
Kris Rohrmann, Marvin Sandner, Phil Meier, Marcus Prochaska · 2018
Magnetoresistive sensors fit well the requirements of advanced anti-lock braking systems for passenger cars. However, novel vehicle concepts such as hybrids and electric cars as well as increasing quality and reliability requirements demand an improvement of their performance. In this paper a novel readout methodology is presented, which linearizes the transfer function of magnetoresistive sensors in the frequency domain. This eliminates the offsets of the sensor elements that leads to a significant reduction of lifetime and temperature drift. Additionally, the costs and size of anisotropic magnetoresistive sensors for wheel speed measurement are reduced, since a magnetic biasing becomes unnecessary. Furthermore, an integrated readout circuit as well measurement results are presented.