TL/H/11884
L
January 1996
LM1208/LM1209
130 MHz/100 MHz RGB Video Amplifier System
with Blanking
General Description
The LM1208/LM1209 is a very high frequency video amplifi-
er system intended for use in high resolution RGB monitor
applications. In addition to the three matched video amplifi-
ers, the LM1208/LM1209 contains three gated single end-
ed input black level clamp comparators for brightness con-
trol, three matched DC controlled attenuators for contrast
control, and three DC controlled drive attenuators providing
independent full range gain control in each channel for wide
range white balance. All DC control inputs offer high input
impedance and an operation range from 0V to 4V for easy
interface
to
bus
controlled
alignment
systems.
LM1208/LM1209 also contains a blanking circuit which
clamps the video output voltage during blanking to within
0.1V above ground. This feature provides blanking capabili-
ty at the cathodes of the CRT. A spot killer is provided for
CRT phosphor protection during power-down.
The
Features
Y
Three wideband video amplifiers 130 MHz
(4 V
PP
output)
@
b
3 dB
Y
Matched (
g
0.1 dB or 1.2%) attenuators for contrast
control
Y
Three externally gated single ended input comparators
for cutoff and brightness control
Y
0V to 4V, high input impedance DC contrast control
(
l
40 dB range)
Y
0V to 4V, high input impedance DC full range gain con-
trol (Drive) for each video channel (
l
40 dB range)
Y
Spot killer, blanks outputs when V
CC
k
10.6V
Y
Capable of 7 V
PP
output swing (slight reduction in
bandwidth)
Y
Output stage blanking
Y
Output stage directly drives most hybrid or discrete
CRT drivers
Applications
Y
High resolution RGB CRT monitors
Y
Video AGC amplifiers
Y
Wideband amplifiers with gain and DC offset controls
Y
Interface amplifiers for LCD or CCD systems
Block and Connection Diagram
TL/H/11884–1
FIGURE 1
Order Number LM1208N or LM1209N
See NS Package Number N28B
C
1996 National Semiconductor Corporation
RRD-B30M66/Printed in U. S. A.