LM1201N National Semiconductor, LM1201N Datasheet - Page 5

• Manufacturer Part Number: LM1201N
• Description: IC VIDEO AMP SYSTEM 16DIP
• Manufacturer: National Semiconductor

Specifications of LM1201N

• Applications: General Purpose
• Number Of Circuits: 1
• -3db Bandwidth: 170MHz
• Current - Supply: 45mA
• Current - Output / Channel: 28mA
• Voltage - Supply, Single/dual (±): 10.8 V ~ 13.2 V
• Mounting Type: Through Hole
• Package / Case: 16-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *LM1201N; LM1201

Figure 5 is a block diagram of the LM1201 along with the
Figure 6 is a simplified schematic of the LM1201 video am-
Circuit Description
contrast and brightness controls The contrast control is a
DC operated attenuator which varies the AC gain of the
amplifier without introducing any signal distortions or DC
output shift The brightness control function requires a
‘‘sample and hold’’ circuit (black level clamp) which holds
the DC bias of the video amplifier and CRT cathodes con-
stant during the black level reference portion of the video
waveform The clamp comparator when gated on during
this reference period will charge or discharge the clamp
capacitor until the non-inverting input of the clamp compara-
tor matches that of the inverting input voltage which was set
by the brightness control
plifier along with the recommended external components
The IC pin numbers are circled with all external components
shown outside of the dashed line The video input is applied
FIGURE 5 Block Diagram of LM201 Video Amplifier with Contrast and Black Level Control
5
to pin 16 via the 10
video input is through the 10 k
to the 2 6V reference at pin 3 The low frequency roll-off of
the amplifier is set by these two components Transistor Q1
buffers the video signal to the base of Q2 The Q2 collector
current is then directed to the V
V
upon the differential DC voltage at the bases of Q3 and Q4
The Q3 and Q4 differential base voltage is determined by
the contrast control circuit which is described below The
black level DC voltage at the collector of Q4 is maintained
by Q5 and Q6 which are part of the black level clamp circuit
also described below The video signal appearing at the col-
lector of Q4 is then buffered by Q7 and level shifted down
by Z1 and Q8 to the base of Q9 which will then provide
additional system gain
CC2
through Q4 and the 500
F coupling capacitor DC bias to the
CC1
resistor which is connected
load resistor depending
supply through Q3 or to
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