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