TLE4943C

Data Sheet

41

V 1.2, July 2018

3.8

Watchdog Reset after Offset Jump

Figure 28

Reset is triggered after watchdog delay time and signal watchdog

When an offset jump, greater than the amplitude of the magnetic speed signal occurs, no zero crossing is passed

anymore and therefore sensor outputs no speed pulse. Instead, standstill protocol is issued. After transmitting five

standstill protocols (typ. 750ms) the signal watchdog starts. If still no speed pulse is output sensor starts to detect

sensor triggers internal reset and enters uncalibrated mode. Therefore validity of direction, direction information,

validity of airgap and airgap measurement are set to default values. This represents the same status as after

power on. Therefore offset calibration starts again.

dB

Watchdog timer

Signal watchdog

Standstill protocol

Offsetjump

C

D

Uncal Mode

B

A

Reset