IC-MU_17 Datasheet, PDF (38/66 Pages) IC-Haus GmbH – MAGNETIC OFF-AXIS POSITION ENCODER - POLE WIDTH 1.28MM

iC-MU MAGNETIC OFF-AXIS
POSITION ENCODER - POLE WIDTH 1.28MM
Rev D1, Page 38/66
CONVERTER AND NONIUS CALCULATION
Converter principle
The system consist of two real-time tracking converters,
each with a resolution of 12 bits for the master track
and nonius track. Above the maximal permissible input
frequency the status bits FRQ_CNV is set. The tracking
converter can’t follow the input signal any more. With
a filter setting of type FILT1 and bigger an increased
resolution of 14 bits is available.
A digital filter can be configured with FILT to reduce the
noise of the digital output signals. Using this the digital
angle values of the tracking converter can be filtered.
10 ms
1 ms
100 us
10 us
1 us
0.1 us
0.1 Hz
FILT6
FILT5
FILT4
FILT3
FILT2
FILT1
FILT0
1 Hz
10 Hz
100 Hz
frequency
1 kHz
Figure 32: Filter latency
10 kHz
Synchronization mode
FILT
Code
0x0
0x1
0x2
0x3
0x4
0x5
0x6
Note
Addr. 0x0E; bit 2:0
Typ
Noise sup- Latency
Interpol.
pression (see Figure 32) MAS / NON
FILT0 0 dB
< 1 µs
12 bit
FILT1 15 dB
< 1 µs
14 bit
FILT2 21 dB
2.5 µs
14 bit
FILT3 27 dB
10 µs
14 bit
FILT4 39 dB
FILT5 45 dB
f_sin < 50 Hz: 164 µs
f_sin = 1 kHz: 25 µs
f_sin < 12 Hz: 650 µs
f_sin = 1 kHz: 33 µs
14 bit
14 bit
FILT6 51 dB
f_sin < 3 Hz: 2.6 ms
f_sin = 1 kHz: 41 µs
14 bit
Influences on the max. rotation speed with
incremental output signals are shown in table 78
Table 51: Digital filter features
30
10
3
1
FILT6
FILT5 _FILT4
0.3
FILT3
FILT2
FILT1
FILT0
0.110_−1
10⁰
10¹
10²
10³
10⁴
sine frequency [Hz]
Figure 31: Phase relationship of the filters
Table 52 lists the configurable master period counts
and the resulting bit lengths for nonius synchronization,
and the synchronization bit length used. The parameter
MPC defines thus the nonius system and has to be
chosen according to the magnetic code carrier. If MPC
is switched during operation, command ABS_RESET
must be executed and the track offset values must be
calibrated again.
MPC(3:0)
Addr. 0x0F; bit 3:0
Code
Master
period
count
Nonius
period
count
Bit length
0x4
16
15
4
0x5
32
31
5
0x6
64
63
6
for MU as Nonius-Multiturn *)
0x7
128
127
7
0x8
256
255
8
0x9
512
511
9
0xA
1024
1023
10
0xB
2048
2047
11
0xC
4096
4095
12
Note
*) see page 43
Synchroni-
sation bit
length
8
7
6
5
4
3
2
1
0
Table 52: Master period count and the resulting bit
lengths
LIN selects the hall sensor arrangement to linear or
rotative for axial or radial/linear scanning (see table
53).