TLE4955C-E2 Datasheet, PDF (6/24 Pages) Infineon Technologies AG – Differential Hall Effect Transmission Speed Sensors

Confidential
TLE4955C-E2
Functional Description
1.2
Block Diagram
Supply Voltage Generation
Bandgap
Oscillator
Supply
Comparator
B₂
2 (right)
B3
3 (center )
B₁
1 (left)
Amplifier Speed Path
∆Bspeed
gs1
speed signal: ∆Bspeed=B2-B1
Offset DAC
LPF
Pre-Amplifier with dB dir calculation
dir ^∆Bdir
calc
gd
direction signal: ∆Bdir=B3-(B2+B1)/2
LPF
Figure 3 Block Diagram
Tracking
ADC
Algorithm
multiplexed
ADC
Offset
Calculation
Output
Protocol
Direction
Detection
Adaptive
Hysteresis
Comparator
Vibration
Detection
V_DD
Current
Modulator
GND
ESD
The speed signal calculated out of B₂-B₁, is amplified, low pass filtered and digitized. An algorithm in the digital
core for peak detection and offset calculation will be executed. The offset is fed back into the speed signal path
with a digital to analog converter for offset correction. The adaptive hysteresis comparator compares the
speed signal to the hysteresis value. During uncalibrated mode, the output of the speed pulse is triggered in
the digital core by exceeding a certain threshold.
The direction signal is calculated out of the three Hall signals. The direction signal is amplified, filtered, and
digitized. In the digital core the direction and the vibration detection information is determined and the data
protocol is issued. The direction information is converted to a current modulated signal.
Data Sheet
6
Version 1.00
2016-06-01