clc5622 National Semiconductor Corporation, clc5622 Datasheet - Page 11

• Manufacturer Part Number: clc5622
• Description: Dual, High Output, Video Amplifier
• Manufacturer: National Semiconductor Corporation

where Z
CLC5622 and |Z
The load voltage and current will fall in the ranges:
The CLC5622’s high output drive current and low
distortion make it a good choice for this application.
Full Duplex Cable Driver
The circuit shown in Figure 16 below, operates as a full
duplex cable driver which allows simultaneous transmis-
sion and reception of signals on one transmission line.
The circuit on either side of the transmission line uses are
CLC5622 as a cable driver, and the second CLC5622 as
a receiver. V
is an attenuated version of V
R
set the DC gain of the CLC5622, which is used in a
difference mode. R
offset. The transmitting CLC5622’s are shown in a unity
gain configuration because they consume the least
power of any gain, for a given load. For proper operation
we need R
V
V
inA
oB
m1
R
t1
is used to match the transmission line. R
CLC5622
o(5622)
Figure 16: Full Duplex Cable Driver
CLC5622
+
R
R
-
1/2
f2
f1
f2
1/2
oA
+
-
= R
R
is an attenuated version of Vi
(j ) is the output impedance of the
g2
o(5622)
g2
R
t2
R
.
m1
t2
I
V
o
(j )| << R
o
provides good CMRR and DC
I
max
Z
n
0
inB
n V
.
max
m
.
R
m1
R
t2
R
g2
CLC5622
CLC5622
+
-
1/2
nA
R
R
1/2
f1
f2
+
-
, while V
f2
and R
R
V
V
oB
t1
g2
inB
oA
11
The receiver output voltages are:
where A is the attenuation of the cable, Z
output impedance of the CLC5622 (see the Closed-Loop
Output Resistance plot), and
We selected the component values as follows:
These values give excellent isolation from the other input:
The CLC5622 provides large output current drive, while
consuming little supply current, at the nominal bias point.
It also produces low distortion with large signal swings
and heavy loads. These features make the CLC5622 an
excellent choice for driving transmission lines.
V
outA(B)
CLC5622 at unity gain
R
R
of the transmission line
R
value for the CLC5622 at A
R
f1
m1
f2
t2
= 1.2k , the recommended value for
= R
V
= Z
(R || R ) –
inA(B)
g2
V
V
o
f2
inB(A)
oA(B)
= 50 , the characteristic impedance
= 750
A
g2
V
inB(A)
38dB, f
R
2
R
2
m1
m1
|
Z
, the recommended
1
25
o(5622)
v
5.0MHz
R
R
= 2
g2
f2
(j )
http://www.national.com
o(5622)
Z
|
o(5622)
<< R
R
(j ) is the
m1
m1
(j )
.