IC-NQC_11 Datasheet, PDF (26/29 Pages) IC-Haus GmbH – 13-bit Sin/D CONVERTER WITH SIGNAL CALIBRATION

iC-NQC
preliminary
13-bit Sin/D CONVERTER WITH SIGNAL CALIBRATION
APPLICATION NOTES
Rev D1, Page 26/29
Principle input circuits
1Vss to 120S
PSIN
NSIN
RS
120S
SENSOR
case
PSIN
+
-
-
NSIN
+
INPUT SIN
VREF
iC-NQC
Figure 19: Input circuit for voltage signals of 1 Vpp
with no ground reference. When ground
is not separated the connection NSIN to
VREF must be omitted.
R3
1kS
V-GEN
1Vpp
R1
1kS
-
R2
1kS
+
R4
1kS
PSIN
+
-
-
NSIN
+
INPUT SIN
VREF
iC-NQC
Figure 21: Input circuit for non-symmetrical voltage
or current source signals with ground ref-
erence (adaptation via resistors R3, R4).
R1
10kS
-
+
R2
10kS
PSIN
+
-
Ip
10µApp
In
10µApp
-
NSIN
+
INPUT SIN
VREF
iC-NQC
Figure 23: Input circuit for complementary low-side
current source outputs, such as for op-
toencoder iC-WG.
11µApp
PSIN
NSIN
RS1
25kS
RS2
25kS
SENSOR
case
PSIN
+
-
-
NSIN
+
INPUT SIN
VREF
iC-NQC
Figure 20: Input circuit for current signals of 11 µA
with no ground reference. Offset calibra-
tion is not possible with this circuit.
+5V
R001
1kS
R002
1kS
PSIN
+
-
V-GEN
2Vpp
-
NSIN
+
INPUT SIN
VREF
iC-NQC
Figure 22: Simplified input wiring for non-
symmetrical voltage signals with ground
reference.
+TTL
-TTL or open
RS3
5kS
1kS
PSIN
+
5kS
-
+SIN
-SIN
120S
ENCODER case
RS1
5kS
RS2
5kS
CS1
220pF
RS4
1kS
CS2
47nF
GAIN= 10
-
NSIN
+
INPUT SIN
VREF
iC-NQC
Figure 24: Combined input circuit for 11 µA, 1 Vpp
(with 120 Ω termination) or TTL encoder
signals. RS3/4 and CS1 serve as protec-
tion against ESD and transients.