SAA4974 Philips, SAA4974 Datasheet - Page 8

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

Philips Semiconductors
7
7.1
7.1.1
An up-converter to 4 : 2 : 2 is applied with a linear
interpolation filter for creation of the extra samples. These
are combined with the original samples from the 4 : 1 : 1
stream.
7.1.2
The Digital Colour Transient Improvement (DCTI) is
intended for U and V signals originating from a 4 : 1 : 1
source. Horizontal transients are detected and enhanced
without overshoots by differentiating, make absolute and
again differentiating the U and V signals separately. This
results in a 4 : 4 : 4 U and V bandwidth. To prevent third
harmonic distortion, typical for this processing, a so called
over the hill protection prevents peak signals to become
distorted.
1998 Apr 21
V
YOUT
V
SSA3
DDA2
Besic without ADC
SYMBOL
FUNCTIONAL DESCRIPTION
Digital processing at 2f
4 : 1 : 1
DCTI
TO
4 : 2 : 2
PIN
78
79
80
UP
analog ground 3
Y analog output
analog supply voltage 2 (3.3 V)
-
CONVERSION
H
level
8
Via I
threshold (i.e. immunity against noise), selection of simple
or improved first differentiating filter (see Fig.3), limit for
pixel shift range (see Fig.5), common or separate
processing of U and V signals, hill protection mode (i.e. no
discolourations in narrow colour gaps), low-pass filtering
for U and V signals (see Fig.6) and a so called super hill
mode, which avoids discolourations in transients within a
colour component.
2
DESCRIPTION
C-bus it is possible to control: gain width (see Fig.4),
Product specification
SAA4974H