LM1203N datasheet(6/16 Pages) NSC

6 / 16 page

Applications Information

Figure 4 shows the block diagram of a typical analog RGB

color monitor The RGB monitor is used with CADCAM

work stations PC’s arcade games and in a wide range of

other applications that benefit from the use of color display

terminals The RGB color monitor characteristics may differ

in such ways as sweep rates screen size CRT color trio

spacing (dot pitch) or in video amplifier bandwidths but will

still be generally configured as shown in

Figure 4 Separate

horizontal and vertical sync signals may be required or they

may be contained in the green video input signal The video

input signals are usually supplied by coax cable which is

terminated in 75X at the monitor input and internally ac cou-

pled to the video amplifiers These input signals are approxi-

mately 1 volt peak to peak in amplitude and at the input of

the high voltage video section approximately 6V peak to

peak At the cathode of the CRT the video signals can be as

high as 60V peak to peak One important requirement of the

three video amplifiers is that they match and track each

other over the contrast and brightness control range The

Figure 4 block labeled ‘‘VIDEO AMPLIFICATION WITH

GAIN AND DC CONTROL’’ describes the function of the

LM1203 which contains the three matched video amplifiers

contrast control and brightness control

TLH9178 – 4

FIGURE 4 Typical RGB Color Monitor Block Diagram

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LM1203N Datasheet(PDF) 6 Page - National Semiconductor (TI)