IC-MH8_14 Datasheet, PDF (12/25 Pages) IC-Haus GmbH – 12 BIT ANGULAR HALL ENCODER

iC-MH8
12 BIT ANGULAR HALL ENCODER
preliminary
Rev A1, Page 12/25
28 27 26 25 24 23 22
1
2
3
4
5
N 6
7
S
21
20
19
18
17
16
15
8 9 10 11 12 13 14
C041007-1
Figure 4: Zero position of the magnet
28 27 26 25 24 23 22
1
2
3
4
5
N 6
7
S
21
20
19
18
17
16
15
8 9 10 11 12 13 14
=0
28 27 26 25 24 23 22
(top view)
1
S
21
2
20
3
19
4
18
5
17
6
16
7
N
15
8 9 10 11 12 13 14
>0
0
+0.5 V
V_SIN= V_PSOUT - V_NSOUT V_COS= V_PCOUT - V_NCOUT
-90°
90° 180° 270° 360°
-0.5 V
C041007-4
Figure 5: Pattern of the analog sensor signals with
the angle of rotation
Hall Signal Processing
The iC-MH8 module has a signal calibration function
that can compensate for the signal and adjustment er-
rors. The Hall signals are amplified in two steps. First,
the range of the field strength within which the Hall sen-
sor is operated must be roughly selected. The first
amplifier stage can be programmed in the following
ranges:
GAING(1:0)
Addr. 0x00; bit 7:6
00
5-fold
01
10-fold
10
15-fold
11
20-fold
Table 6: Range selection for Hall signal amplification
used. With the amplitude control (ENAC = ’1’) acti-
vated, the GAINF register bits have no effect.
GCC(6:0)
0x00
0x01
...
0x3F
0x40
...
0x7F
Addr. 0x01; bit 6:0
1,000
1,0015
exp(
ln(20)
2048
·
GCC)
1,0965
0,9106
exp(−
ln(20)
2048
·
(128
−
GCC))
0,9985
Table 8: Amplification calibration cosine
The operating range can be specified in advance in
accordance with the temperature coefficient and the
magnet distance. The integrated amplitude control can
correct the signal amplitude between 1 and 20 via an-
other amplification factor. Should the control reach the
range limits, a different signal amplification must be se-
lected via GAING.
GAINF(5:0)
0x00...0x02
0x03
...
0x3E...0x3F
Addr. 0x00; bit 5:0
1,098
1,150
exp(
ln(20)
64
·
GAINF )
18,213
The GCC register is used to correct the sensitivity of
the sine channel in relation to the cosine channel. The
cosine amplitude can be corrected within a range of
approximately ±10%.
ENAC
0
1
Addr. 0x01; bit 7
amplitude control deactivated
amplitude control active
Table 9: Activation of amplitude control
Table 7: Hall signal amplification
The second amplifier stage can be varied in an addi-
tional range. With the amplitude control (ENAC = ’0’)
deactivated, the amplification in the GAINF register is
The integrated amplitude control can be activated with
the ENAC bit. In this case the differential signal am-
plitude is adjusted to 4 Vss and the values of GAINF
have no effect here.