ADV7183AKST Analog Devices Inc, ADV7183AKST Datasheet - Page 37

• Manufacturer Part Number: ADV7183AKST
• Description: IC VIDEO DECODER NTSC 80-LQFP
• Manufacturer: Analog Devices Inc
• Type: Video Decoderr

Specifications of ADV7183AKST

• Applications: Projectors, Recorders, Security
• Voltage - Supply, Analog: 3.15 V ~ 3.45 V
• Voltage - Supply, Digital: 1.65 V ~ 2 V
• Mounting Type: Surface Mount
• Package / Case: 80-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

DIGITAL NOISE REDUCTION (DNR)
Digital noise reduction is based on the assumption that high
frequency signals with low amplitude are probably noise, and
that their removal therefore improves picture quality.
DNR_EN Digital Noise Reduction Enable,
Address 0x4D [5]
The DNR_EN bit enables the DNR block or bypasses it.
Table 79. DNR_EN Function
DNR_EN
0
1 (default)
DNR_TH[7:0] DNR Noise Threshold, Address 0x50 [7:0]
The DNR_TH[7:0] value is an unsigned 8-bit number used to
determine the maximum edge that will be interpreted as noise
and therefore blanked from the luma data. Programming a large
value into DNR_TH[7:0] causes the DNR block to interpret
even large transients as noise and remove them. The effect on
the video data will therefore be more visible.
Programming a small value causes only small transients to be
seen as noise and to be removed.
The recommended DNR_TH[7:0] setting for A/V inputs is
0x04, and the recommended DNR_TH[7:0] setting for tuner
inputs is 0x0A.
Table 80. DNR_TH Function
DNR_TH[7:0]
0x08 (default)
Description
Bypass DNR (disable).
Enable digital noise reduction on the luma
data.
Description
Threshold for maximum luma edges to be
interpreted as noise.
Rev. B | Page 37 of 104
COMB FILTERS
The comb filters of the ADV7183A have been greatly improved
to automatically handle video of all types, standards, and levels
of quality. Two user registers are available to customize comb
filter operation.
Depending on whichever video standard has been detected (by
autodetection) or selected (by manual programming), the
NTSC or PAL configuration registers are used. In addition to
the bits listed in this section, there are some further ADI
internal controls; contact ADI for more information.
NTSC Comb Filter Settings
Used for NTSC-M/J CVBS inputs.
NSFSEL[1:0] Split Filter Selection NTSC, Address 0x19 [3:2]
The NSFSEL[1:0] control selects how much of the overall signal
bandwidth is fed to the combs. A narrow split filter selection
gives better performance on diagonal lines, but leaves more dot
crawl in the final output image. The opposite is true for select-
ing a wide bandwidth split filter.
Table 81. NSFSEL Function
NSFSEL[1:0]
00 (default)
01
10
11
CTAPSN[1:0] Chroma Comb Taps NTSC, Address 0x38 [7:6]
Table 82. CTAPSN Function
CTAPSN[1:0]
00
01
10 (default)
11
Description
Narrow
Medium
Medium
Wide
Description
Do not use.
NTSC chroma comb adapts 3 lines (3 taps)
to 2 lines (2 taps).
NTSC chroma comb adapts 5 lines (5 taps)
to 3 lines (3 taps).
NTSC chroma comb adapts 5 lines (5 taps)
to 4 lines (4 taps).
ADV7183A