TLE4943C datasheet(19/48 Pages) INFINEON

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TLE4943C

Data Sheet

V 1.2, July 2018

Figure 13

Starting wheel movement during standstill protocol using bit stump suppression

Handling of “Direction Validity” and “Direction” at the standstill protocol:

At any standstill DR is transmitted as zero (default value) and GDR is transmitted as invalid (=0). With the first 5

standstill protocols in a row, the direction algorithm is reset. Therefore at following next three zero crossings

(speed pulses) direction detection and change of direction detection takes place (GDR=invalid, DR=default) and

GDR is valid and correspondig direction is output at third speed pulse after standstill.

Handling of “Validity of signal amplitude measurement” within standstill protocol:

Validity (SLM) of signal measurement is transmitted as 1 (invalid) and signal amplitude (Level in relation to LR) is

transmitted as 0 during standstill protocol. With the first 5 standstill protocols in a row, the SLM/LM is reset to

invalid. SLM remains invalid until two new extrema in dB are found. Depending on the amplitude of dB and phase

of the standstill protocol, SLM is valid with the second, third or fourth speed protocol after every 5th standstill

protocol.

Handling of Error Bit “Air Gap Reserve” (=LR bit) within standstill protocol:

It is transmitted as "0" (no error) in the standstill protocol.

It is reset to 0 with the first 5 standstill protocols in a row. The standstill protocol LR remains “0” (no error) until two

new extrema in dB are found.

The initial bit enables the speed pulse to always be preceded by a current level Ilow for a duration of at least tp/2.

This is helpful for the detection of the speed pulse in the ECU.

50us tp/2=25 µs

28mA

14mA

7mA

out

Increment

1) Last started bit of standstill protocol will be tranmitted completely

2) Delay of 25us at llow

3) Speed pulse issued

Standstill protocol due to

no edge within last150 ms

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