iC-MH8
12 BIT ANGULAR HALL ENCODER
Rev A0.9, Page 12/25
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(top view)
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S
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N
a > 0
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9
10 11 12 13 14
8
9
10 11 12 13 14
a = 0
0
VCOS= VPCOS- VNCOS
VSIN= VPSIN- VNSIN
+2V
-90°
90°
180°
270°
360°
a
-2V
8
9
10 11 12 13 14
C041007-3
C040907-1
Figure 5: Pattern of the analog sensor signals with
the angle of rotation
Figure 4: Zero position of the magnet
Hall Signal Processing
The iC-MH8 module has a signal calibration function The second amplifier stage can be varied in an addi-
that can compensate for the signal and adjustment er- tional range. With the amplitude control (ENAC = ’0’)
rors. The Hall signals are amplified in two steps. First, deactivated, the amplification in the GAINF register is
the range of the field strength within which the Hall sen- used. With the amplitude control (ENAC = ’1’) acti-
sor is operated must be roughly selected. The first vated, the GAINF register bits have no effect.
amplifier stage can be programmed in the following
ranges:
GCC(6:0)
0x00
0x01
...
Addr. 0x01; bit 6:0
1,000
1,0015
exp(
GAING(1:0)
Addr. 0x00; bit 7:6
ln(20)
2048
00
01
10
11
5-fold
· GCC)
10-fold
15-fold
20-fold
0x3F
0x40
...
1,0965
0,9106
ln(20)
exp(− 2048 · (128 − GCC))
0x7F
0,9985
Table 6: Range selection for Hall signal amplification
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.
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
Addr. 0x01; bit 7
amplitude control deactivated
amplitude control active
0
1
GAINF(5:0)
0x00
...
Addr. 0x00; bit 5:0
1,000
1,048
Table 9: Activation of amplitude control
0x02
0x03
...
exp(ln(20) · GAINF − 2)
64
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.
0x3F
17,38
Table 7: Hall signal amplification
ICHAUS [ IC-HAUS GMBH ]
