TLE4921-5U Datasheet, PDF (9/24 Pages) Infineon Technologies AG – Dynamic Differential Hall Effect Sensor IC

TLE4921-5U
Application Configurations
Two possible applications are shown in Figure 7 and Figure 8 (Toothed and
Magnet Wheel).
The difference between two-wire and three-wire application is shown in Figure 9.
Gear Tooth Sensing
In the case of ferromagnetic toothed wheel application the IC has to be biased by
the south or north pole of a permanent magnet (e.g. SmCO₅ (Vacuumschmelze
VX145)) with the dimensions 8 mm × 5 mm × 3 mm) which should cover both Hall
probes.
The maximum air gap depends on
− the magnetic field strength (magnet used; pre-induction) and
− the toothed wheel that is used (dimensions, material, etc.; resulting differential
field)
a centred distance
of Hall probes
b Hall probes to
IC surface
L IC surface to
tooth wheel
a = 2.5 mm
b = 0.3 mm
N
S
b
L
a
AEA01259
Figure 5 Sensor Spacing
T
Conversion DIN – ASA
m = 25.4 mm/p
d
AEA01260
T = 25.4 mm CP
DIN
ASA
d diameter (mm)
p diameter pitch
z number of teeth
PD pitch diameter
m module m = d/z (mm) CP circular pitch
T pitch T = π=× m (mm)
Figure 6 Toothed Wheel Dimensions
p = z/d (inch)
PD = z/p (inch)
CP = 1 inch ×=π/p
Data Sheet
9
2002-08-02