LM1282 National Semiconductor, LM1282 Datasheet - Page 10

• Manufacturer Part Number: LM1282
• Description: 110 MHz RGB Video Amplifier System with On Screen Display (OSD)
• Manufacturer: National Semiconductor

www.national.com
No.
Pin
11
10
21
12
13
14
26
27
28
15
16
17
19
24
1
2
3
4
5
8
6
9
7
Pin Descriptions
Red OSD Input
Green OSD Input
Blue OSD Input
Video/OSD Switch
Red Video In
Green Video In
Blue Video In
V
Ground
V
Video Contrast
OSD Contrast
Blue Drive
Green Drive
Red Drive
Clamp Gate
Blank Gate
Blue Clamp Cap
Green Clamp Cap
Red Clamp Cap
CC1
REF
Name
Pin
Schematic
10
These inputs accept standard TTL inputs. Each color is either
fully on (logic high) or fully off (logic low). Connect unused
pins to ground with a 47k resistor.
This input accepts a standard TTL input.
Connect to ground with a 47k resistor when not using OSD.
Video inputs. These inputs must be AC Coupled with a
minimum of a 1 µF cap, 10 µF is perferred. DC restoration is
done at these inputs. A series resistor of about 33
also be used.
Power supply pins (excluding output stage)
Ground pins. All grounds are internally connected and must
also be connected on the PCB.
Pin used for additional filter capacitor to internal reference.
The voltage at this pin is 2.0V.
Contrast control pins:
Drive control pins:
Both pins accept TTL inputs and are active low. The clamp
gate provides DC restoration of the video signal. The blank
gate forces the video outputs to below 200 mV.
The external clamp cap is charged and discharged to the
correction voltage needed for DC restoration. 0.1 µF is the
recommended value.
H = OSD
L = Video
4V — no attenuation
0V — over 60 dB attenuation
4V — no attenuation
0V — 12 dB attenuation
Description
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