LM1212 230 MHz Video Amplifier System with OSD Blanking
August 1996
LM1212
230 MHz Video Amplifier System with OSD Blanking
General Description
The LM1212 is a very high frequency video amplifier system
intended for use in high resolution monochrome or RGB
color monitor applications with OSD In addition to the wide-
band video amplifier the LM1212 contains a gated differen-
tial input black level clamp comparator for brightness con-
trol a DC controlled attenuator for contrast control and a
DC controlled sub contrast attenuator for drive control The
DC control for the contrast attenuator is pinned out sepa-
rately to provide a more accurate control system for RGB
color monitor applications All DC controls offer a high input
impedance and operate over a 0V鈥?V range for easy inter-
face to bus controlled alignment systems During the OSD
window the output is blanked to
k
0 4V The LM1212 oper-
ates from a nominal 12V supply but can be operated with
supply voltages down to 8V for applications that require re-
duced IC package power dissipation characteristics
Y
Y
Y
Y
Y
Y
Y
Externally gated comparator for brightness control
0V to 4V high input impedance DC contrast control
(
l
40 dB range)
0V to 4V high input impedance DC drive control
(
g
3 dB range)
Ouput blanked to
k
0 4V for OSD window
Easy to parallel three LM1212s for optimum color
tracking in RGB systems
Output stage clamps to 0 65V and provides up to 9V
output voltage swing
Output stage directly drives most hybrid or discrete
CRT amplifier stages
Applications
Y
Y
Y
Y
Features
Y
Y
High resolution CRT monitors with OSD
Video switches
Video AGC amplifier
Wideband amplifier with gain and DC offset control
Wideband video amplifier
(f
b
3 dB
e
230 MHz at V
O
e
4 V
PP
)
t
r
t
f
e
1 5 ns at V
O
e
4 V
PP
Block and Connection Diagram
TL H 12354 鈥?1
Order Number LM1212N
See NS Package Number N20A
C
1996 National Semiconductor Corporation
TL H 12354
RRD-B30M86 Printed in U S A
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www national com