adv7189b Analog Devices, Inc., adv7189b Datasheet - Page 29

• Manufacturer Part Number: adv7189b
• Description: Multiformat Sdtv Video Decoder
• Manufacturer: Analog Devices, Inc.

The filter plots in
S-VHS 18 (widest) shaping filter settings.
PAL notch filter responses. The NTSC-compatible notches are
shown in
Figure 13. Y S-VHS 18 Extra Wideband Filter (CCIR 601 Compliant)
–100
–120
–10
–20
–30
–40
–50
–60
–70
–20
–40
–60
–80
–10
–20
–30
–40
–50
–60
–70
0
0
0
F igure 15.
1 8 0 H
0
0
0
Figure 12. Y S-VHS Combined Responses
COMBINED Y ANTIALIAS, CCIR MODE SHAPING FILTER,
Figure 14. PAL Notch Filter Response
COMBINED Y ANTIALIAS, S-VHS LOW-PASS FILTERS,
2
2
2
F igure 12 show the S-VHS 1 (narrowest) to
1 7 8 H
COMBINED Y ANTIALIAS, NTSC NOTCH FILTERS,
4
4
4
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
Y RESAMPLE
Y RESAMPLE
Y RESAMPLE
6
6
6
8
8
8
F igure 14 shows the
1 7 9 H
10
10
10
12
12
12
Rev. B | Page 29 of 104
CHROMA FILTER
Data from the digital fine clamp block is processed by three sets
of filters. Note: the data format at this point is CVBS for CVBS
inputs, or chroma only for Y/C or Cr/Cb interleaved for YCrCb
input formats.
x
x
x
The plots in
together.
Chroma Antialias Filter (CAA). The ADV7189B over-
samples the CVBS by a factor of 2 and the Chroma/UV
by a factor of 4. A decimating filter (CAA) is used to
preserve the active video band and to remove any out-of-
band components. The CAA filter has a fixed response.
Chroma Shaping Filters (CSH). The shaping filter block
can be programmed to perform a variety of low-pass
responses. It can be used to selectively reduce the band-
width of the chroma signal for scaling or compression.
Digital Resampling Filter. This block is used to allow
dynamic resampling of the video signal to alter parameters
such as the time base of a line of video. Fundamentally, the
resampler is a set of low-pass filters. The actual response is
chosen by the system without user intervention.
–10
–20
–30
–40
–50
–60
–70
0
0
F igure 16 show the overall response of all filters
1 8 1 H
Figure 15 . NTSC Notch Filter Response
2
COMBINED Y ANTIALIAS, NTSC NOTCH FILTERS,
4
FREQUENCY (MHz)
Y RESAMPLE
6
8
10
ADV7189B
12