clc5623 National Semiconductor Corporation, clc5623 Datasheet - Page 11

• Manufacturer Part Number: clc5623
• Description: Triple, High Output, Video Amplifier
• Manufacturer: National Semiconductor Corporation

V
Set up the CLC5623 as a difference amplifier:
Make the best use of the CLC5623’s output drive
capability as follows:
where R
ance, V
maximum Output Current.
Match the line’s characteristic impedance:
Select the transformer so that it loads the line with a
value very near Z
impedance of the CLC5623 also affects the match. With
an ideal transformer we obtain:
where Z
CLC5623 and |Z
The load voltage and current will fall in the ranges:
The CLC5623’s high output drive current and low
distortion make it a good choice for this application.
in
R
R
t1
g1
Return Loss
+
CLC5623
-
max
1/3
Figure 17: Differential Line Driver wtih
R
eq
o(5623)
g2
R
f1
is the transformed value of the load imped-
is the Output Voltage Range, and I
V
d/2
Load Impedance Conversion
R
t2
V
V
(j ) is the output impedance of the
in
d
o(5623)
CLC5623
+
-
R
o
1/3
20 log
R
m
2
f2
over frequency range. The output
I
V
o
(j )| << R
o
-V
R
R
n
R
d/2
1
L
m
eq
10
I
max
R
R
R
R
n
R
R
m/2
m/2
Z
n V
R
R
n
eq
g1
f1
o
2 V
eq
eq
L
2
I
max
max
m
1:n
Z
max
.
o 5623
2
Z
o
R
R
g2
f2
UTP
j
Z
o
,dB
max
I
o
is the
R
L
V
+
-
o
11
Bandpass Filter
Figure 18 illustrates a low-sensitivity bandpass filter and
design equations. This topology utilizes the CLC5623’s
closely matched amplifiers to obtain low op-amp
sensitivity at high frequencies. The third CLC5623 is
used as a buffer to obtain low output impedance. The
overall circuit gain is unity. For additional gain, the third
CLC5623 can be configured as a non-inverting amplifier.
To design the filter, choose C and then determine values for
R and R
and Q factor.
Instrumentation Amplifier
An instrumentation circuit is shown on the front page and
reproduced in Figure 19. The DC CMRR can be fine
tuned by adjusting R
V
V
750
1
2
Figure 19: Instrumentation Amplifier
1
Figure 18: Bandpass Filter Topology
based on the desired resonant frequency (f
R
V
R
in
CLC5623
+
CLC5623
-
+
-
2 f C
1/3
1/3
R
750
750
R
1
1
CLC5623
r
1/3
+
-
C
1
R
.
1
750
750
QR
R
750
R
1
CLC5623
CLC5623
-
+
+
-
750
1/3
1/3
R
CLC5623
-
+
R
C
1/3
f
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V
o
V
out
= 3(V
2
- V
1
)
r
)