iC-MN 25-BIT NONIUS ENCODER
WITH 3-CH. SAMPLING 13-BIT Sin/D INTERPOLATION
Rev D1, Page 25/59
ORC_M
Addr. 0x06; bit 5:4
ORC_S
Addr. 0x16; bit 5:4
Addr. 0x26; bit 5:4
and
ORC_N
Code
Range
CVDCx = (1 − kc) · V(PCi) + kc · V(NCi)
0
1
2
3
maxVOSC_x = 3 * REFVOS
maxVOSC_x = 6 * REFVOS
Using MPS_x (9:0) and MPC_x (9:0) ks and kc should
be configured in such a way that the AC fraction is min-
imal with both voltages.
maxVOSC_x = 18 * REFVOS
maxVOSC_x = 36 * REFVOS
Table 23: Offset range cosine
MPS_M
MPS_S
MPS_N
Addr. 0x03; bit 4:0
Addr. 0x02; bit 7:3
Addr. 0x13; bit 4:0
Addr. 0x12; bit 7:3
Addr. 0x23; bit 4:0
Addr. 0x22; bit 7:3
SVDC = (1 − ks) · V(PSi) + ks · V(NSi)
ks = 0.3333
The achievable angle accuracy following interpolation
is affected by the internal signal strength and the offset
calibration step width, depending on the set correction
range and reference source. By way of example these
dependencies are shown in the following table, for half
and full scale signal levels (FS means 6 Vpp).
Code
0x000
0x001
...
ks = 0.3336
...
Range
x Source
maxVOSC_x
maxVOSS_x
Cal. Step
Width (LSB)
Limitation Of
0x3FF
ks = 0.6666
Angle Accuracy
@ 100 % (6 Vpp)
@ 50 % (3 Vpp)
Table 20: Intermediate voltage sine
3 x 0.25 V
6 x 0.25 V
6 x 0.5 V
750 mV
1.5 V
3 V
732 µV
none (>13 bit)
none (>13 bit)
MPC_M
MPC_S
MPC_N
Addr. 0x04; bit 6:0
Addr. 0x03; bit 7:5
Addr. 0x14; bit 6:0
Addr. 0x13; bit 7:5
Addr. 0x24; bit 6:0
Addr. 0x23; bit 7:5
CVDC = (1 − kc) · V(PCi) + kc · V(NCi)
kc = 0.3333
1465 µV
4396 µV
8789 µV
none (>13 bit)
none (>13 bit)
0.08°, ca. 12 bit
0.16°, ca. 11 bit
18 x 0.5 V
9 V
0.16°, ca. 11 bit
0.32°, ca. 10 bit
Code
0x000
0x001
...
Table 24: Offset calibration and influence on angle ac-
curacy
kc = 0.3336
...
0x3FF
kc = 0.6666
The sine and cosine offsets are calibrated by a linear
voltage divider using OFS_x (10:0) and OFC_x (10:0).
Table 21: Intermediate voltage cosine
OFS_M
OFS_S
OFS_N
Addr. 0x06; bit 3:0
Addr. 0x05; bit 7:1
Addr. 0x16; bit 3:0
Addr. 0x15; bit 7:1
Addr. 0x26; bit 3:0
Addr. 0x25; bit 7:1
OFS_x = OffsS_x*maxVOSS_x
OffsS_x = 0
The calibration range for the offset of sine and cosine
is dependent on the source selected by REFVOS and
is set using ORS_x (1:0) and ORC_x (1:0). The offset
correction accuracy is influenced with the above.
ORS_M
ORS_S
ORS_N
Addr. 0x05; bit 0
Addr. 0x04; bit 7
Addr. 0x15; bit 0
Addr. 0x14; bit 7
Addr. 0x25; bit 0
Addr. 0x24; bit 7
Code
0x000
0x001
0x002
...
OffsS_x = -0.0009
OffsS_x = -0.0019
...
0x3FF
0x400
0x401
0x402
...
OffsS_x = -1
Code
Range
OffsS_x = 0
0
1
2
3
maxVOSS_x = 3 * REFVOS
maxVOSS_x = 6 * REFVOS
maxVOSS_x = 18 * REFVOS
maxVOSS_x = 36 * REFVOS
OffsS_x = 0.0009
OffsS_x = 0.0019
...
0x7FF
OffsS_x = 1
Table 22: Offset range sine
Table 25: Offset voltage sine
ICHAUS [ IC-HAUS GMBH ]
