IC-LNG_14 Datasheet, PDF (22/30 Pages) IC-Haus GmbH – 16-BIT OPTO ENCODER

iC-LNG 16-BIT OPTO ENCODER ^preliminary
WITH SPI AND SERIAL / PARALLEL OUTPUTS
SIGNAL CONDITIONING
Rev B1, Page 22/30
iC-LNG has various parameters for signal conditioning.
The gain of the digital tracks and the analog track can
both be set using parameter GR. A gain factor of 1.33
(GR = 0x01) can be used for most applications.
GR
Code
0x00
0x01
0x02
0x03
Add. 0x07, bit 1:0
Gain factor
1.0
1.33
1.6
2.0
NCOS. The offset of signal NSIN must then be cali-
brated to the calibrated offset of signal PSIN.
OSP
Code
0x00
0x01
...
0x7F
Add. 0x02, bit 6:0
Offset value
0.45 · VDDA
0.4508 · VDDA
(0.45
+
OSP·0.1
127
)
·
VDDA
0.55 · VDDA
Table 17: PSIN offset
Table 15: Gain range (all tracks)
OSN
Code
The sine/cosine signals can be calibrated in ampli- _0x00
tude and offset (Figure 14). To this end the LED _0x01
current control must be programmed to sum con- _...
trol (LCSET(6) = 1) and the internal calibration signals _0x7F
switched to analog outputs PSIN, NSIN, PCOS, and
NCOS (TA = 0x1).
Add. 0x03, bit 6:0
Offset value
0.45 · VDDA
0.4508 · VDDA
(0.45
+
OSN ·0.1
127
)
·
VDDA
0.55 · VDDA
Table 18: NSIN offset
TA = 0x1
TMUX = 0x0D
or
TMUX = 0x0E
PSIN
NSIN
PCOS
VPx
VNx
NCOS
GNDA
VDDAH
(x = S, C)
VPx
VDDAH
VNx
Figure 14: Sine/cosine signal calibration
To calibrate the cosine signals TMUX must be pro-
grammed to 0x0E. The amplitude of signals PCOS and
NCOS can then be calibrated to the same amplitude as
that of the sine signals using parameter GS.
GC
Code
0x00
0x01
...
0x3F
Add. 0x01, bit 5:0
Gain factor
1.0
1.01
1+GC·0.0053
1−GC·0.0053
2.0
To calibrate the sine signals TMUX must be pro-
grammed to 0x0D. The amplitude of signals PSIN and
NSIN can then be calibrated using parameter GS. The
target amplitude is 500 mVp.
GS
Code
0x00
0x01
...
0x3F
Add. 0x00, bit 5:0
Gain factor
1.0
1.01
1+GS·0.0053
1−GS·0.0053
2.0
Table 16: PSIN and NSIN gain
The offsets of PSIN and NSIN can be calibrated sep-
arately using parameters OSP and OSN. The offset
of signal PSIN must be calibrated to reference signal
VDDAH. This signal is available in test mode at pin
Table 19: PCOS and NCOS gain
The offsets of PCOS and NCOS can be calibrated sep-
arately using parameters OCP and OCN. The offset
of signal PCOS must be calibrated to reference signal
VDDAH. This signal is available in test mode at pin
NCOS. The offset of signal NCOS must then be cali-
brated to the calibrated offset of signal PCOS.
OCP
Code
0x00
0x01
...
0x7F
Add. 0x04, bit 6:0
Offset value
0.45 · VDDA
0.4508 · VDDA
(0.45
+
OCP ·0.1
127
)
·
VDDA
0.55 · VDDA
Table 20: PCOS offset