TLE4953 Datasheet, PDF (6/20 Pages) Infineon Technologies AG – Differential Two-Wire Hall Effect Sensor IC

TLE4953
TLE4953C
Functional Description
The differential Hall Effect IC detects the motion of ferromagnetic or permanent magnet
structures by measuring the differential flux density of the magnetic field. To detect the
motion of ferromagnetic objects the magnetic field must be provided by a backbiasing
permanent magnet. Either the South or North pole of the magnet can be attached to the
rear, unmarked side (remark: rear side may contain data matrix code) of the IC package.
Magnetic offsets of up to ± 20 mT and mechanical offsets are cancelled out through a
self-calibration algorithm. Only 2 transitions are necessary for the self-calibration
procedure. After the initial self-calibration sequence switching occurs when the input
signal crosses the adaptive threshold on the rising magnetic edge.
The ON and OFF state of the IC are indicated by High and Low current consumption.
Each rising magnetic edge of the magnetic input signal triggers an output pulse.
Magnetic Signal
Output Signal
Pulse
Length
AED03189
Figure 3 Output Pulses on magnetic rising edge
In addition to the speed signal, the following information is provided by varying the length
of the output pulses (PWM modulation):
Speed signal = S
The speed signal is issued at the first output pulse after start up and when the magnetic
frequency is above 1kHz.
Direction of rotation left = DR-L
DR-L information is issued in the output pulse length when the active target wheel in front
of the Hall Effect IC moves from the pin V_CC to the pin GND.
Direction of rotation right = DR-R
DR-R information is issued in the output pulse length when the active target wheel in
front of the Hall Effect IC moves from the pin GND to the pin V_CC.
Data Sheet
3
V 4.0, 2010-04