LM1208
130 MHz/85 MHz RGB Video Amplifier System with
Blanking
General Description
The LM1208 is a very high frequency video amplifier system
intended for use in high resolution RGB monitor applications.
In addition to the three matched video amplifiers, the
LM1208 contains three gated single ended input black level
clamp comparators for brightness control, three matched DC
controlled attenuators for contrast control, and three DC
controlled sub-contrast 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. The LM1208 also contains
a blanking circuit which clamps the video output voltage
during blanking to within 0.1V above ground. This feature
provides blanking capability at the cathodes of the CRT.
A spot killer is provided for CRT phosphor protection during
power-down.
Features
n Three wideband video amplifiers 130 MHz (LM1208) @
?3 dB (4 VPP output)
n Matched (±0.1 dB or 1.2%) attenuators for contrast
control
n ESD susceptibility above 3 kV
n Three externally gated single ended input comparators
for cutoff and brightness control
n 0V to 4V, high input impedance DC contrast control
(>40 dB range)
n 0V to 4V, high input impedance DC full range gain
control (Drive) for each video channel (> 40 dB range)
n Spot killer, blanks output when VCC < 10.6V
n Capable of 7 VPP output swing (slight reduction in
bandwidth)
n Output stage blanking
n Output stage directly drives most hybrid or discrete CRT
drivers
Applications
n High resolution RGB CRT monitors
n Video AGC amplifiers
n Wideband amplifiers with gain and DC offset controls
n Interface amplifiers for LCD or CCD systems