IC-MG_14 Datasheet, PDF (13/22 Pages) IC-Haus GmbH – 8-Bit Sin/Cos INTERPOLATION IC WITH RS422 DRIVER

iC-MG
8-Bit Sin/Cos INTERPOLATION IC WITH RS422 DRIVER
S/C SIGNAL PATH and CALIBRATION
Rev D1, Page 13/22
The analog voltage signals needed to calibrate the sine
signals can be measured in Calibration Mode 2. The
characteristic digital parameters for offset, amplitude
and phase errors can be measured in System Test
Mode.
S/C Gain Settings
The gain is set in four stages:
1. The sensor supply tracking is shut down and the
constant current source for the PWR output set to
a suitable output current (register ADJ; current value
close to the later operating point).
2. The coarse gain is selected so that differential signal
amplitudes of ca. 1 Vpp are produced internally (signal
PCHx vs. NCHx for the sine or cosine channel).
3. Using fine gain factor GFC the cosine signal ampli-
tude is then adjusted to 1 Vpp.
4. The sine signal amplitude can then be calibrated to
the cosine signal amplitude via fine gain factor GFS.
Px
VPx
Nx
VNx
GND
R0
VPNx
GRSC
Code
0x0
0x1
0x2
0x3
0x4
0x5
0x6
0x7
Adr 0x04, bit 2:0
Range with RSC=0x9
0.5
1.0
1.3
1.7
2.2
2.6
3.3
4.0
Range with RSC=0x9
2.0
4.1
5.3
6.7
8.7
10.5
13.2
16.0
Table 10: S/C-Channel Gain Range
GFC
Code
0x00
0x01
...
0x1F
Adr 0x04, bit 7:3
Factor
1.00
1.06
GFC
6.25 31
6.25
Table 11: Gain Factor Cosine
GFS
Code
0x00
0x01
...
0x7F
Adr 0x06, bit 2:0, Adr 0x05, bit 7:4
Factor
1.0
1.015
GFS
6.25 124
6.53
Table 12: Gain Factor Sine
Figure 2: Definition of 1 Vpp signal. Termination R0
must be high-ohmic during all Test and
Calibration modes.