SAA4974 Philips, SAA4974 Datasheet - Page 21

• Manufacturer Part Number: SAA4974
• Description: Besic without ADC
• Manufacturer: Philips

Philips Semiconductors
11 APPLICATION
The SAA4974H supports two different up-converter
concepts. The simple one is shown in Fig.13. In this
application only one field memory SAA4955TJ is needed
for a 100 Hz conversion based on a field repetition
algorithm (AABB mode). The concept can be upgraded by
a noise reduction based on a motion adaptive field
recursive filter if the SAA4956TJ is used instead of the
SAA4955TJ.
The SAA4974H supports a dual-clock system.
The acquisition clock is taken from the digital front-end.
The display control is based on a clock generated by an
external H-PLL. By this structure the stability of the display
is enhanced compared to a one-clock system if an
unstable source like a VCR is used as an input.
For low-cost applications it is possible to run the IC as a
one-clock system.
1998 Apr 21
handbook, full pagewidth
Besic without ADC
white 255
black 16
0
8-BIT INPUT
1.34 V
1023
64
0
Fig.12 Luminance levels.
display_mode = 1
21
The second system supported by the SAA4974H is shown
in Fig.14. This concept needs two field memories
(SAA4955TJ) and the signal processing IC MELZONIC
(SAA4991WP). The SAA4991WP allows a vector based
motion estimation and compensation for a display of
100 Hz pictures in high-end TV sets which is free of motion
artefacts. It additionally provides a variable vertical zoom
function, noise and cross colour reduction. Furthermore a
multi-PIP feature is supported making use of the field
memories.
10-BIT OUTPUT
1023
937
852
767
288
256
171
86
0
display_mode = 0
Product specification
SAA4974H
MGM693