Analog Devices ADV8005, Hardware Reference Manual

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ADV8005 Hardware Reference Manual UG-707
Filter Pass-Band Ripple (dB) 1 3 dB Bandwidth (MHz) 2
Chroma 1.3 MHz 0.09 1.395
Chroma 2.0 MHz 0.048 2.2
Chroma 3.0 MHz Monotonic 3.2
Chroma CIF Monotonic 0.65
Chroma QCIF Monotonic 0.5
1 Pass-band ripple is the maximum fluctuation from the 0 dB response in the pass band, measured in decibels. The pass band is defined to have 0 Hz to fc (Hz) frequency
limits for a low-pass filter and 0 Hz to f1 (Hz), and f2 (Hz) to infinity for a notch filter, where fc, f1, and f2 are the −3 dB points.
2
3 dB bandwidth refers to the −3 dB cutoff frequency.
The luma filter supports several different frequency responses, including two low-pass responses, two notch responses, an extended (SSAF)
response with or without gain boost attenuation, a CIF response, and a QCIF response. These can be configured using
luma_filter_sel[2:0] .
luma_filter_sel[2:0] , Encoder Map, Address 0xE480[4:2]
This signal is used to configure the luma filters for SD data.
Function
luma_filter_sel[2:0] Description
000 LPF NTSC
001 LPF PAL
010 Notch NTSC
011 Notch PAL
100 (default) SSAF Luma
101 Luma CIF
110 Luma QCIF
111 Reserved
If SD SSAF gain is enabled, there are 13 response options in the −4 dB to +4 dB range. The desired response can be programmed using register
0xA2. The variation in frequency responses is shown in
Figure 112 , Figure 113 , and Figure 114 . The registers required for enabling and
controlling the SSAF filter gain are described below.
Figure 112: SD Luma SSAF Filter, Programmable Responses
FREQUENCY (MHz)
4
7
M
AG
NI
T
UDE
(
d
B)
2
–2
–6
–8
–12
0
–4
5
–10
6 0 1 2 3 4
06398-
036
Rev. A | Page 251 of 317