IC-MHL200 Datasheet, PDF (22/33 Pages) IC-Haus GmbH – 12-BIT LINEAR / ROTARY POSITION HALL ENCODER

iC-MHL200
12-BIT LINEAR / ROTARY POSITION HALL ENCODER
SINE-TO-DIGITAL CONVERTER
Rev C1, Page 22/33
The iC-MHL200 device integrates two separate sine-
to-digital converters. A high-resolution 12-bit converter
for the ABZ incremental signals can be programmed in
broad ranges of the resolution and generate quadrature
signals even at the highest speed and resolution.
The converter operates for the commutation signals
UVW independently of this and can be set in the zero
point separately from the quadrature converter. This
enables the commutation at other angles based on the
index track Z.
Incremental signals
A
--
1
1
1
1
B
1
1
'-
-
1
1
1
1
1
1
1
1
1¹ 0^°/o
•
50¹¹ %1¹¹¹
1
1•
100 ^°/oi¹
+ _AArel
Figure 21: ABZ signals and relative accuracy
The incremental signals can be inverted again indepen-
dently of the output drivers. As a result, other phase
angles of A and B relative to the index pulse Z can be
generated. The standard is A and B high level for the
zero point, i.e. Z is equal to high.
CFGRES(7:0)
Addr. 0x06; bit 7:0
Value
Interpolation factor
Resolution
0x00
1
4
0x01
2
8
...
...
...
0x7e
127
508
0x7f
128
512
0x80
256
1024
0x81
512
2048
0x82
1 024
4096
Table 15: Programming interpolation factor
Figure 21 shows the position of the incremental signals
around the zero point. The relative accuracy of the
edges to each other at a resolution setting of 10 bit is
better than 10 %. This means that, based on a period
at A or B, the edge occurs in a window between 40 %
and 60 %.
CFGHYS(1:0)
Addr. 0x08; bit 7:6
Value
Hysteresis
0x0
0.17 °
0x1
0.35 °
0x2
0.7 °
0x3
1.4 °
The resolution of the 12-bit converter can virtually be
set as desired. Any resolution can be set up to an in-
terpolation factor of 128, i.e. 512 edges per rotation. At
higher resolutions, only the binary resolutions can be
set, i.e. 256, 512 and 1 024. In the highest resolution
with an interpolation factor of 1 024, 4 096 edges per
rotation are generated and 4 096 angular steps can
be differentiated. Even in the highest resolution, the
absolute position can be calculated in real time at the
maximum speed. After the resolution is changed, a
module reset is triggered internally and the absolute
position is recalculated.
Table 17: Programming angular hysteresis
With rotating direction reversal, an angular hysteresis
prevents multiple switching of the incremental signals
at the reversing point. The angular hysteresis corre-
sponds to a slip which exists between the two rotating
directions. However, if a switching point is approached
from the same direction, then the edge is always gener-
ated at the same position on the output. The following
Figure shows the generated quadrature signals for a
resolution of 360 edges per rotation (interpolation factor
90) and a set angular hysteresis of 1.4 °.
10°
CFGAB(1:0)
Addr. 0x08; bit 1:0
Value
Function
0x0
A and B not inverted
0x1
B inverted, A normal
0x2
A inverted, B normal
0x3
A and B inverted
Table 16: Inversion of AB signals
0°
−10°
A
B
Z
0°
1.4°
0°
Figure 22: Quadrature signals for rotating direction
reversal (hysteresis 1.4 °)