iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
Rev D1, Page 27/59
ANALOG PARAMETERS
ACOC_M(4:0)
Addr. 0x0C; bit 4:0
Signal Level Controller
Code
0x00
0x01
...
Setpoint
By tracking the sensor’s power supply via the con-
trolled current sources (outputs ACOM, ACOS and
ACON) iC-MN can keep the sine/cosine track signals
for the ensuing sine-to-digital converter constant re-
gardless of temperature and aging effects.
3.125% * Imax(ACOM)
6.25% * Imax(ACOM)
...
0x1E
0x1F
96.875% * Imax(ACOM)
100% * Imax(ACOM)
When adjusting the signal conditioning a constant cur-
rent source is used in place of the controlled current
source, the set current of which can be adjusted using
ACOR_M(6:0) or ACOR_x(5:0) (x = S, N). This current
must be so low as to leave enough reserve for tem-
perature and aging effects and ensure that no unnec-
essary power dissipation is generated. However, the
source current may not be too low so as to permit a
better signal contrast and improved signal to noise ra-
tio. Using this current the signal calibration can then be
performed so that the sine/cosine signals at the sine-
to-digital converter have a (differential) value of 6 Vpp
in their calibrated state. Once calibration has proved
successful the signal level controller can be activated.
Table 30: Current source setpoint, ACOM output
ACOT_S(7:6)
ACOT_N(7:6)
Addr. 0x1D; bit 0
Addr. 0x1C; bit 7
Addr. 0x2D; bit 0
Addr. 0x2C; bit 7
Code
00
Operating mode
Quadratic regulation active
Sum regulation active
Constant current source mode
Not permitted
01
10
11
Table 31: Controller op. mode, ACOS/ACON outputs
There are three integrated signal level control units in
iC-MN, all of which are powered by VACO. It is thus
possible to regulate each track individually or, in opti-
cal systems with an LED, for example, all three tracks
using the master signal level controller. If the control
unit’s working range is exceeded, an error is gener-
ated.
ACOR_S(5)
Addr. 0x1C; bit 5
ACOR_N(5)
Addr. 0x2C; bit 5
Code
Current range Imax(ACOS), Imax(ACON)
0
1
5 mA
10 mA
Table 32: Current source range, ACOS/ACON outputs
ACOT_M(8:7)
Addr. 0x0D; bit 0
Addr. 0x0C; bit 7
ACOC_S(4:0)
ACOC_N(4:0)
Addr. 0x1C; bit 4:0
Addr. 0x2C; bit 4:0
Code
00
Operating mode
Code
0x00
0x01
...
Setpoint
Quadratic regulation active*
Sum regulation active
Constant current source mode
Not permitted
3.125% * Imax(ACOS, ACON)
6.25% * Imax(ACOS, ACON)
...
01
10
11
0x1E
0x1F
96.875% * Imax(ACOS, ACON)
100% * Imax(ACOS, ACON)
*) Quadratic regulation of V()scq =
p
(V(PSOUT − V(NSOUT))2 + (V(PCOUT − V(NCOUT))2
Table 33: Current source setpoint, ACOS/ACON out-
put
Table 28: Controller op. mode, ACOM output
ACOR_M(6:5)
Addr. 0x0C; bit 6:5
Code
00
Current range Imax(ACOM)
5 mA
01
10 mA
25 mA
50 mA
10
11
Table 29: Current source range, ACOM output
ICHAUS [ IC-HAUS GMBH ]
