tle4942 Infineon Technologies Corporation, tle4942 Datasheet - Page 30

• Manufacturer Part Number: tle4942
• Description: Differential Two-wire Hall Effect Sensor-ic For Wheel Speed Applications With Direction Detection
• Manufacturer: Infineon Technologies Corporation

Behaviour close to the magnetic thresholds
Real non-perfect magnetic signals and intrinsic thermal noise cause amplitude
variations. Very close to the magnetic thresholds a mix of output pulse widths
representing the referring magnetic values occur. For similar reasons pulse widths of 90,
180, 360, 720 µs can be observed occasionally for single pulses at
Behaviour close to speed v5 (
Signal imperfections like duty cycle and jitter result in a mix of output pulses with and
without assembly bit (EL) information. Input signal duty cycles apart from 50% increase
the range where both pulse widths appear.
Dependency of direction detection on input signal pitch
The direction detection is optimized for a target wheel pitch of 5 mm where it will work
down to
pitches other than 5 mm the magnetic input signal has to be increased to compensate
for the inevitable signal attenuation.
Figure 2
Data Sheet
B
warning
Degradation of speed and direction signal at
sinusoidal input signals =
1 .8
1 .6
1 .4
1 .2
1 .0
0 .8
0 .6
0 .4
0 .2
0
. (
2
B
warning
3
and direction detection thresholds meet at 5 mm pitch). For
4
f
EL-bit =
5
ca. 117 Hz)
f
6
(pitch)
30
7
B
warning
8
Pitch
,
B
Limit
9
Speed
Direction
, (
B
10
EL
)
B
Limit
AED 03716
mm
.
TLE4942-1C
V3.1, 2005-03
TLE4942-1
12