TLE4921-3U Datasheet, PDF (9/19 Pages) Infineon Technologies AG – Dynamic Differential Hall Effect Sensor IC

TLE 4921-3U
Application Configurations
Two possible applications are shown in Figure 7 and 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 centered distance
of Hall probes
b Hall probes to
IC surface
L IC surface to
tooth wheel
a = 2.5 mm
b = 0.3 mm
Figure 5 Sensor Spacing
b
L
N
S
a
AEA01259
T
d
AEA01260
DIN
d
diameter (mm)
z
number of teeth
m module m = d/z (mm)
T
pitch T = π × m (mm)
Conversion DIN – ASA
m = 25.4 mm/p
T = 25.4 mm CP
ASA
p
diameter pitch p = z/d (inch)
PD pitch diameter PD = z/p (inch)
CP circular pitch CP = 1 inch × π/p
Figure 6 Toothed Wheel Dimensions
Data Sheet
9
2000-07-01