TLI5012BE1000_15 Datasheet, PDF (25/37 Pages) Infineon Technologies AG – GMR-Based Angle Sensor

4.4
Interfaces
TLI5012B E1000
Specification
4.4.1 Incremental Interface (IIF)
The Incremental Interface (IIF) emulates the operation of an optical quadrature encoder with a 50% duty cycle. It
transmits a square pulse per angle step, where the width of the steps can be configured from 9bit (512 steps per
full rotation) to 12bit (4096 steps per full rotation) within the register MOD_4 (IFAB_RES). The rotation direction is
given either by the phase shift between the two channels IFA and IFB (A/B mode) or by the level of the IFB channel
(Step/Direction mode), as shown in Figure 4-7 and Figure 4-8. The incremental interface can be configured for
A/B mode or Step/Direction mode in register MOD_1 (IIF_MOD).
Using the Incremental Interface requires an up/down counter on the microcontroller, which counts the pulses and
thus keeps track of the absolute position. The counter can be synchronized periodically by using the SSC interface
in parallel. The angle value (AVAL register) read out by the SSC interface can be compared to the stored counter
value. In case of a non-synchronization, the microcontroller adds the difference to the actual counter value to
synchronize the TLI5012B E1000 with the microcontroller.
After startup, the IIF transmits a number of pulses which correspond to the actual absolute angle value. Thus, the
microcontroller gets the information about the absolute position. The Index Signal that indicates the zero crossing
is available on the IFC pin.
Sensors with preset IIF are available as TLI5012B E1000.
A/B Mode
The phase shift between phases A and B indicates either a clockwise (A follows B) or a counterclockwise (B
follows A) rotation of the magnet.
Incremental Interface
(A/B Mode)
90° el . Phase shift
Phase A ^VH
V_L
Phase B ^VH
VL
Counter 0 1 2 3
4
5
6
7
6
Figure 4-7 Incremental interface with A/B mode
Step/Direction Mode
Phase A pulses out the increments and phase B indicates the direction.
5
4 3 21
Step ^VH
V_L
Direction ^VH
V_L
Counter _{0 1 2 3}
4
Incremental Interface
(Step /Direction Mode)
5
6
7
6
Figure 4-8 Incremental interface with Step/Direction mode
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4
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Data Sheet
25
Rev. 1.1, 2015-09