Data Sheet

5

1.0

2018-02

TLE4959C FX Flexible Transmission Speed Sensor

Functional Description

1.6

Rotational Direction

The direction signal is digitized by an analog to digital converter (direction ADC) and fed into the digital core.

Depending upon the rotation direction of the target wheel, the signal of the center probe anticipates or lags

behind for 90°. This phase relationship is evaluated and converted into rotation direction information by

sampling the signal of the center probe in the proximity of the zero crossing of the “speed” bridge signal.

The first pulse after power (power on pulse) has a different length to signalize that there is no direction

information available .

Forward/backward pulse length could be inverted via EEPROM settings.

Figure 5

Direction definition

In case of high speed has been enable, the direction detection is switched off as soon as the frequency reach

4.3 kHz. To enter or leave the high frequency, two consecutive periods have to be larger or smaller than the

frequency limit. this may delay the high frequency pulse at power on.

1.7

Vibration Suppression

The magnetic signal amplitude and the direction information are used for detection of parasitic magnetic

signals. Unwanted magnetic signal can be caused by angular or air gap vibrations. If an input signal is

identified as a vibration the output pulse will be suppressed.

Monocell

speed

signal

direction

signal

Branded

side

1 2 3

N

S