vpx3224d ETC-unknow, vpx3224d Datasheet - Page 12

• Manufacturer Part Number: vpx3224d
• Description: Video Pixel Decoders
• Manufacturer: ETC-unknow

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VPX 3225D, VPX 3224D
In the NTSC compensated mode, Fig. 2–7 c), the color
signal is averaged for two adjacent lines. Thus, cross-
color distortion and chroma noise is reduced. In the
NTSC combfilter mode, Fig. 2–7 d), the delay line is in
the composite signal path, thus allowing reduction of
cross-color components, as well as cross-luminance.
The loss of vertical resolution in the luminance channel
is compensated by adding the vertical detail signal with
removed color information.
2.2.8. Luminance Notch Filter
If a composite video signal is applied, the color informa-
tion is suppressed by a programmable notch filter. The
position of the filter center frequency depends on the
subcarrier frequency for PAL/NTSC. For SECAM, the
notch is directly controlled by the chroma carrier fre-
quency. This considerably reduces the cross-lumi-
nance. The frequency responses for all three systems
are shown in Fig. 2–6. In S-VHS mode, this filter is by-
passed.
PAL/NTSC notch filter
SECAM notch filter
Fig. 2–6: Frequency responses of the luma
notch filter for PAL, NTSC, SECAM
10
10
0
0
dB
dB
0
0
2
2
4
4
6
6
8
8
10
10
MHz
MHz
CVBS
CVBS
CVBS
CVBS
Fig. 2–7: NTSC color decoding options
CVBS
Luma
Chroma
a) conventional
c) compensated
d) comb filter
a) conventional
b) S-VHS
Fig. 2–8: PAL color decoding options
Fig. 2–9: SECAM color decoding
8
8
8
8
8
8
8
Process.
Chroma
Notch
filter
Delay
1 H
Process.
Process.
Process.
Chroma
Chroma
Chroma
Notch
Notch
filter
filter
Process.
Chroma
Notch
filter
C C
Y
r b
PRELIMINARY DATA SHEET
Delay
Delay
Delay
1 H
1 H
1 H
Luma
Chroma
b) S-VHS
Process.
Chroma
Delay
Notch
8
8
filter
1 H
MUX
Process.
Chroma
Y
Y
Y
C
C
C
r
r
r
C
C
C
Y
Y
b
b
b
C
C
C
Micronas
Y
r
r
r
C
C
C
b
b
b