PRELIMINARY

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Application Configurations

Two possible applications are shown in Figure 8 and Figure 9 (Toothed and Magnet

Wheel).

The difference between two-wire and three-wire application is shown in Figure 12 for

the TLE4925C and in Figure 13 for the TLE4925.

Gear Tooth Sensing

In the case of ferromagnetic toothed wheel application the IC has to be biased by the

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 8

Sensor Spacing

Conversion DIN – ASA

m = 25.4 mm/p

T = 25.4 mm CP

DIN

d

diameter (mm)

z

number of teeth

m

module m = d/z (mm)

T

pitch T =

π × m (mm)

ASA

p

diameter pitch

p = z/d (inch)

PD

pitch diameter

PD = z/p (inch)

CP

circular pitch CP = 1 inch

× π/p

Figure 9

Toothed Wheel Dimensions

N

S