LM1203AN National Semiconductor, LM1203AN Datasheet - Page 13

• Manufacturer Part Number: LM1203AN
• Description: IC VIDEO AMP RGB 150MHZ 28DIP
• Manufacturer: National Semiconductor

Specifications of LM1203AN

• Applications: General Purpose
• Number Of Circuits: 3
• -3db Bandwidth: 70MHz
• Current - Supply: 73mA
• Current - Output / Channel: 28mA
• Voltage - Supply, Single/dual (±): 10.8 V ~ 13.2 V
• Mounting Type: Through Hole
• Package / Case: 28-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *LM1203AN

Figure 10 shows the configuration for a three channel high
Figure 11 shows a complete RGB video preamplifier circuit
Additional Applications of the LM1203A
frequency amplifier with non gated DC feedback Pin 14 is
tied low to turn on the clamp comparators (feedback amplifi-
ers) The inverting inputs (Pins 17 21 26) are connected to
the amplifier outputs from a low pass filter Additional low
frequency filtering is provided by the clamp caps The drive
resistors can be made variable or fixed at values between
0
the DC output is set to approximately 4V The high frequen-
cy response will be dependent upon external peaking at the
drive pins
using
(MM74HC86) is used to generate the back porch clamp sig-
nal from the composite sync input signal The composite H
and 300
FIGURE 10 Three Channel High Frequency Amplifier with Non-gated DC Feedback (Non-video Application)
the
LM1203A
Maximum output swings are achieved when
A
quad
Exclusive-OR
gate
13
Sync input signal may have either polarity The back porch
clamp signal applied to LM1203A’s pin 14 allows clamping
the video output signals to the black reference level there-
by providing DC restoration The back porch clamp pulse
width is determined by the time constant due to the product
of R11 and C15 For fast horizontal scan rates the back
porch clamp pulse width can be made narrower by decreas-
ing the value of R11 or C15 or both Note that an MM74C86
Exclusive-OR gate may also be used however the pin out
is different than that of the MM74HC86
For optimum performance and maximum bandwidth high
speed buffer transistors (Q1 Q2 and Q3 in Figure 11 ) are
recommended The 2N5770 NPN transistors maintain high
speed at high currents when driving the inputs of high volt-
age CRT drivers
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TL H 11441 – 14
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