TLI5012BE1000_15 Datasheet, PDF (22/37 Pages) Infineon Technologies AG – GMR-Based Angle Sensor

4.3.5 Signal Processing
TLI5012B E1000
Specification
TLI5012B E1000
Microcontroller
X
GMR
Y
GMR
SD-
ADC
SD-
ADC
Filter
Angle
Calculation
Filter
t _adelSSC
t_adelIIF
IF
t_delIF
Figure 4-4 Signal path
The signal path of the TLI5012B E1000 is depicted in Figure 4-4. It consists of the GMR-bridge, ADC, filter and
angle calculation. The delay time between a physical change in the GMR elements and a signal on the output
depends on the filter and interface configurations. In fast turning applications, this delay causes an additional
rotation speed dependent angle error.
The TLI5012B E1000 has an optional prediction feature, which serves to reduce the speed dependent angle error
in applications where the rotation speed does not change abruptly. Prediction uses the difference between current
and last two angle values to approximate the angle value which will be present after the delay time (see
Figure 4-5). The output value is calculated by adding this difference to the measured value, according to
Equation (4.1).
α (t + 1) = α (t) + α (t − 1) − α (t − 2)
(4.1)
Angle
Magnetic field
direction
Sensor output
With
Without
Prediction Prediction
t_adel
t_upd
Figure 4-5 Delay of sensor output
Data Sheet
22
time
Rev. 1.1, 2015-09