clc412 National Semiconductor Corporation, clc412 Datasheet - Page 8

• Manufacturer Part Number: clc412
• Description: Dual Wideband Video Op Amp
• Manufacturer: National Semiconductor Corporation

Differential Line Receiver. Figures 5 and 5a show two
different implementations of an instrumentation amplifier
which convert differential signals to single-ended. Figure
5a allows CMRR adjustment through R
High-Speed Instrumentation Amplifier.
For applications requiring higher CMRR the composite
circuit of Figure 6 uses the two amplifiers of the CLC412
to create balanced inputs for the CLC420 voltage-
feedback op amp. The DC CMRR can be fine tuned
through the adjustment of R
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R
V
1
in
-V
1
V
in
in
R
2
+V
1
R
R
in
in
V
1
½CLC412
3
R
R
in
V
in
2
½CLC412
in
R
A
R
½CLC412
+
-
-
+
R
R
R
R
(A
1
2
v
R
f
R
½CLC412
=R
-
+
1
2
v
= +1
f 1
f 2
1
= -1V/V)
f
R
f
R
R
g
Figure 5a
1
R
g
Figure 4
Figure 5
Figure 6
R
2
1
A
B
-V
R
-
+
+
½CLC412
-
in
½CLC412
R
R
R
g
a
g
+V
b
R
A
g
R
R
. Further improvement of
b
v
f
f
R
1
1
2
in
A
½CLC412
= -0.5V/V
-
+
(A
v
2
v
-
+
CLC420
R
2
= 1.5V/V
f
= -1V/V)
R
R
f
½CLC412
R
R
R
2
R
A
o
o
R
g
.
in
1
2
R
v
=R
1
f
=
= -10
R
o
f
in
/10
R
2
V
o
out
V
out
V
1
out
R
V
o
out
8
CMRR over frequency can be achieved through the
placement of an RC network between the outputs (A and
B) of the two amplifiers of the CLC412.
Non-Inverting Current-Feedback Integrator.
The circuit of Figure 7 achieves its high-speed integration
by placing one of the CLC412's amplifiers in the feedback
loop of the second amplifier configured as shown.
Low-Noise Wide-Bandwidth Transimpedance
Amplifier. Figure 8 implements a low-noise
transimpedance amplifier using both channels of the
CLC412. This circuit takes advantage of the lower input-
bias-current noise of the non-inverting input and achieves
negative feedback through the second CLC412 channel.
The output voltage is set by the value of R
compensation is achieved through the adjustment of R
Buffered 2nd-Order Sallen-Key Low-Pass Filter.
Figure 9 shows one implementation of a 2nd order
Sallen-Key low pass filter buffered by one of the CLC412's
channels. The CLC412 enables greater precision since
it provides the advantage of very low output impedance
and very linear phase throughout the pass-band.
V
V
I
s
out
in
V
in
s
V
2
R
in
+
C
in
in
s
R
+
½CLC412
-
R C
T
½CLC412
R
+
-
1 1
1
R
R
g
f
R C
C
R R C C
2
½CLC412
1
+
-
1 2
2
K
Figure 7
C
R
R
Figure 8
Figure 9
R
f
f
o
A
g
R
2
1 2
1
R C
2
1
½CLC412
2
K
V
9
2
+
½CLC412
-
o
R
R
R
+
-
R
2
R
g
f
V
f
2
C
R R C C
2
2
in
2
1 2
2
sRC
R
R
R
1
2
b
1
R
V
1 2
R
1
o
C
o
1
f
1
+
½CLC412
-
while frequency
V
o
Z( s
V
R
out
T
IR
)
s
F
G G
G G
H
s
f
A
R
V
R
2
1
out
f
g
p
p
I
J J
J J
K
T
.