clc5602 National Semiconductor Corporation, clc5602 Datasheet - Page 8

• Manufacturer Part Number: clc5602
• Description: Dual, High Output, Video Amplifier
• Manufacturer: National Semiconductor Corporation

Feedback Resistor Selection
The feedback resistor, R
frequency response of a current feedback amplifier.
Optimum performance of the CLC5602, at a gain of
+2V/V, is achieved with R
response plots in the Typical Performance sections
illustrate the recommended R
recommended values of R
width with minimal peaking. Within limits, R
adjusted to optimize the frequency response.
As a rule of thumb, if the recommended R
then the bandwidth will be cut in half.
Unity Gain Operation
The recommended R
is 1k . R
inverting node may require a slight increase in R
maintain a flat frequency response.
Load Termination
The CLC5602 can source and sink near equal amounts
of current. For optimum performance, the load should be
tied to V
Driving Cables and Capacitive Loads
When driving cables, double termination is used to
prevent reflections. For capacitive load applications, a
small series resistor at the output of the CLC5602 will
improve stability and settling performance. The
Frequency Response vs. C
Figure 7, gives the recommended series resistance value
for optimum flatness at various capacitive loads.
Transmission Line Matching
One method for matching the characteristic impedance
(Z
appropriate resistor at the input or output of the amplifier.
http://www.national.com
o
) of a transmission line or cable is to place the
Decrease R
extend bandwidth
Increase R
compress bandwidth
Figure 7: Frequency Response vs. C
cm
.
g
is left open. Parasitic capacitance at the
1M
1k
V
+
-
o
= 1V
f
C
f
1k
to roll off frequency response and
R
L
to peak frequency response and
s
pp
= 100pF
= 20
f
R
C
s
R
Frequency (Hz)
for unity gain (+1V/V) operation
L
C
s
= 46.4
C
= 10pF
R
L
L
f
= 1000pF
s
10M
f
= 6.7
equal to 750 . The frequency
f
, affects the loop gain and
provide the maximum band-
1k
f
for several gains. These
L
plot, shown below in
100M
f
is doubled,
L
f
can be
f
to
8
Figure 8 shows typical inverting and non-inverting circuit
configurations for matching transmission lines.
Non-inverting gain applications:
Inverting gain applications:
The input and output matching resistors attenuate the
signal by a factor of 2, therefore additional gain is needed.
Use C
greater frequency range. C
of the amplifier’s output impedance with frequency.
Power Dissipation
Follow these steps to determine the power consumption
of the CLC5602:
The maximum power that the DIP and SOIC packages
can dissipate at a given temperature is illustrated in
Figure 9. The power derating curve for any CLC5602
package can be derived by utilizing the following
equation:
where
T
V
V
JA
amb
1
2
+
+
-
-
= Thermal resistance, from junction to ambient,
= Ambient temperature (°C)
for a given package (°C/W)
R
R
6
Connect R
Make R
Use R
loading caused by the transmission line,
or by parasitics.
Connect R
Make the resistors R
Make R
1
4
1. Calculate the quiescent (no-load) power:
2. Calculate the RMS power at the output stage:
3. Calculate the total RMS power:
Figure 8: Transmission Line Matching
to match the output transmission line over a
P
P
are the RMS voltage and current across the
external load.
P
amp
o
t
= P
3
= (V
Z
Z
1
0
0
5
to isolate the amplifier from reactive
, R
= I
II R
amp
g
3
CC
CC
2
directly to ground.
directly to ground.
, R
g
+ P
- V
R
R
= Z
(V
(175
R
2
R
5
6
3
g
, and R
load
CC
o
o
6
.
) (I
compensates for the increase
- V
CLC5602
4
+
JA
-
, R
1/2
T
load
R
EE
amb
7
f
6
equal to Z
, and R
)
), where V
)
C
R
6
6
7
equal to Z
o
load
.
Z
0
and I
o
.
load
R
7
V
o