clc5622 National Semiconductor Corporation, clc5622 Datasheet - Page 9

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

Layout Considerations
A proper printed circuit layout is essential for achieving
high frequency performance. Comlinear provides
evaluation boards for the CLC5622 (CLC730038-DIP,
CLC730036-SOIC) and suggests their use as a guide for
high frequency layout and as an aid for device testing and
characterization.
General layout and supply bypassing play major roles in
high frequency performance. Follow the steps below as
a basis for high frequency layout:
Evaluation Board Information
A data sheet is available for the CLC730038/ CLC730036
evaluation boards.
provides:
The evaluation boards are designed to accommodate
dual supplies. The boards can be modified to provide
single supply operation. For best performance; 1) do
not connect the unused supply, 2) ground the unused
supply pin.
SPICE Models
SPICE models provide a means to evaluate amplifier
designs. Free SPICE models are available for National’s
monolithic amplifiers that:
Include 6.8 F tantalum and 0.1 F ceramic
capacitors on both supplies.
Place the 6.8 F capacitors within 0.75 inches
of the power pins.
Place the 0.1 F capacitors less than 0.1 inches
from the power pins.
Remove the ground plane under and around the
part, especially near the input and output pins to
reduce parasitic capacitance.
Minimize all trace lengths to reduce series
inductances.
Use flush-mount printed circuit board pins for
prototyping, never use high profile DIP sockets.
Evaluation board schematics
Evaluation board layouts
General information about the boards
1.0
0.8
0.6
0.4
0.2
Figure 9: Power Derating Curves
0
-40 -20
0
Ambient Temperature ( C)
20 40 60 80 100 120
The evaluation board data sheet
IM
IN
140 160
180
9
The readme file that accompanies the diskette lists
released models, and provides a list of modeled parame-
ters. The application note OA-18, Simulation SPICE
Models for National’s Op Amps, contains schematics and
a reproduction of the readme file.
Single Supply Cable Driver
The typical application shown below shows one of the
CLC5622 amplifiers driving 10m of 75
The CLC5622 is set for a gain of +2V/V to compensate
for the divide-by-two voltage drop at V
Single Supply Lowpass Filter
Figures 12 and 13 illustrate a lowpass filter and design
equations. The circuit operates from a single supply of
+5V. The voltage divider biases the non-inverting input to
2.5V. And the input is AC coupled to prevent the need for
level shifting the input signal at the source. Use the
design equations to determine R
on the desired Q and corner frequency.
V
in
0.1 F
Figure 11: Response After 10m of Cable
Support Berkeley SPICE 2G and its many derivatives
Reproduce typical DC, AC, Transient, and Noise
performance
Support room temperature simulations
5k
Figure 10: Single Supply Cable Driver
0.1 F
Application Circuits
V
5k
in
= 10MHz, 0.5V
1k
3
2
CLC5622
+
-
+5V
1/2
8
4
1k
6.8 F
0.1 F
pp
+
20ns/div
1
0.1 F
1
, R
75
2
, C
o
.
http://www.national.com
Coaxial Cable
1
10m of 75
, and C
coaxial cable.
2
based
75
V
o