XENSIV™ TLE4943C Hall differential wheel speed sensor with AK Protocol Infineon's XENSIV™ TLE4943C is an active magnetic field sensor for wheel speed applications. It measures pole or ferromagnetic toothed wheel speed and uses a two-wire current interface with the AK protocol for communication. With fast power-up time, low cut-off frequency, and excellent sensitivity and accuracy, it meets harsh automotive requirements and includes an overmolded 1.8 nF capacitor for improved EMC performance.