CLC412 Datasheet, PDF (8/12 Pages) National Semiconductor (TI) – Dual Wideband Video Op Amp

V_in
R₁
V
in
3
R₂
R_f1
R_g1
-
½CLC412
+
R_o1
R
A_v1 = -0.5V/V
V_out
+
½CLC412
-
R_o2
Rg₂
R_f2
A_v2 = 1.5V/V
Figure 4
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 R₂.
R_f
R_g
R_f
-
½CLC412
+
-
½CLC412
+
V_out1
R_o
R₁
+V_in
R
R₁
(Av₁ = -1V/V)
-V_in
R
(Av₂ = -1V/V)
Figure 5
R2
Rf
R1
-Vin
½CLC412
Av = +1
R
R1=Rf
Rg
+Vin
Rf
½CLC412
Av = -10
R
Rg=Rf/10
Vout
Ro
Figure 5a
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_b. Further improvement of
Vin₁
+
Rin_{1 ½CLC412}
-
Rf1
R
Rf2
-
½CLC412
Vin₂
+
Rin2
A _Rg
B ^Ra
Rb
Rf
-
CLC420
+
Vout
Ro
Rin₁=Rin2
Figure 6
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.
R₂
R₁
+
V_in
R
R_g
-
½CLC412
C
+
R_b
+
½CLC412
-
R₂
V_o
= V_in
R₁
sRC
V_out
Figure 7
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_f while frequency
compensation is achieved through the adjustment of R_T.
Cf
Rf
+
Ro
R
½CLC412
Vo
-
+
Is
Cin
½CLC412
-
RT
Rg2
Rf2
A₂
=
− ^{R f2}
R _g2
V_o =
I_sR _f
FGG IJJ _{1+ R T}
G J ^Z(s)
1
A ₂ω _p
HG KJ ^{s+ ω}p
Figure 8
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.
Vin
+
R ^½CLC412
in
-
R_f
C₁
R₁ R₂
+
V_out
C₂
½CLC412
-
R_f
K_o
R_g
V_{out =}
R₁R₂C₁C₂
V_in
s²
+

s
1
+
1
+
1−
K
9


+
1
^R1^C1 ^R2^C2 ^R2^C2  ^R1^R2^C1^C2
Figure 9
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