iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
Rev D1, Page 23/59
SIGNAL CONDITIONING for MASTER-, SEGMENT- and NONIUS-Channel (x= M,S,N)
DCPOS
Addr. 0x0A; bit 6
Polarity Isensor
Code
VREFin()
2.5 V
0
1
Negative
Positive
1.5 V
Table 12: Input current polarity
RIN
Addr. 0x0A; bit 2:1
Code
Resistance
1.6 kΩ
0
1
2
3
2.3 kΩ
3.2 kΩ
4.6 kΩ
Table 13: Input resistance with I mode
Voltage Signals
If the voltage signals are too large the input signal can
be quartered by an internal divider. The voltage divider
is referenced to the VREFin reference source which is
set by DCPOS. In order to use the input voltage range
of the input amplifier to its full capacity DCPOS should
be set to 1 in voltage divider mode.
Figure 7: Schematic of Input Stage
The input stages for sine and cosine are instrumen-
tation amplifiers and can process current and voltage
signals; selection is made for all three tracks using
UIN. Signal conditioning should be performed in the
order given in the following.
TUIN
Code
0
Addr. 0x0A; bit 3
Function
Not active
UIN
Code
0
Addr. 0x0A; bit 0
Function
1
Voltage divider active
Table 14: Input voltage divider
I Mode: current inputs
V Mode: voltage inputs
1
Table 11: Signal mode
Additionally, using CVREF the user can select whether
VREFin is the reference potential generated internally
or a voltage provided externally.
CVREF
Code
00
Addr. 0x0B; bit 4:3
Function
Generated internally
01
Reserved
10
Internal VREFin() output to pin ACOS*
External ref. voltage supplied to pin ACOS
*) No load permitted, buffer required.
11
Figure 8: Direction of current flow
Note
Table 15: VREF Source Selection
Current Signals
For current signals internal reference VREFin is
adapted to the input current polarity using DCPOS.
The input resistance is set using RIN (1:0). When All other settings are to be carried out for each indi-
selecting the input resistance the average potentials vidual track separately. A small x in the register name
SVDC and CVDC should be between 125 mV and stands for (M)aster, (S)egment and (N)onius respec-
250 mV to obtain a reasonable offset calibration range. tively.
ICHAUS [ IC-HAUS GMBH ]
