TLE4986C-XTS-M47

Programmable True Power On Sensor

General

Data Sheet

9

Revision 1.1, 2014-11-07

2.2

Definition of the Magnetic Field

The magnetic field of a permanent magnet exits from the north pole and enters the south pole. If a north pole is

Figure 2

Definition of the Positive Magnetic Field Direction

2.3

Functional Description

The basic operation of the TLE4986C is to map a „large” positive magnetic field (tooth) into a “low” electrical output

signal and to map a „weak” positive magnetic field (notch) into a “high” electrical output. Optionally the other output

polarity can be chosen by programming the EEPROM. A magnetic field is considered as positive if the North Pole

of a magnet shows towards the rear side of the IC housing. Since backbias-reduced magnetic configurations still

show significant flux densities in one distinct direction the circuit is optimized for one flux direction in order to

provide an optimal signal to noise behavior.

For understanding the operation of the TLE4986C three different phases have to be considered:

•

Initial operation after power up. This phase will be referred to as „initial phase“.

•

Operation following the initialisation before having full information about the target wheel. This phase will be

referred to as “precalibrated phase”.

•

Normal operation with running target wheel. This phase will be referred to as „calibrated phase“.

S

N

Hallprobe

Front side

TLE 4986

( branded)

1

2

3

Vs

Front side

B