Datasheet

ADV7342/ADV7343 Data Sheet
Rev. | Page 56 of 108
FILTERS
Table 43 shows an overview of the programmable filters
available on the ADV7342/ADV7343.
Table 43. Selectable Filters
Filter Subaddress
SD Luma LPF NTSC 0x80
SD Luma LPF PAL 0x80
SD Luma Notch NTSC 0x80
SD Luma Notch PAL 0x80
SD Luma SSAF
0x80
SD Luma CIF 0x80
SD Luma QCIF 0x80
SD Chroma 0.65 MHz 0x80
SD Chroma 1.0 MHz 0x80
SD Chroma 1.3 MHz 0x80
SD Chroma 2.0 MHz
0x80
SD Chroma 3.0 MHz 0x80
SD Chroma CIF 0x80
SD Chroma QCIF 0x80
SD PrPb SSAF 0x82
ED/HD Chroma Input 0x33
ED/HD Sinc Compensation Filter 0x33
ED/HD Chroma SSAF 0x33
SD Internal Filter Response
Subaddress 0x80, Bits[7:2]; Subaddress 0x82, Bit 0
The Y 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. The PrPb
filter supports several different frequency responses, including
six low-pass responses, a CIF response, and a QCIF response, as
shown in Figure 38 and Figure 39.
If SD SSAF gain is enabled (Subaddress 0x87, Bit 4), there are 13
response options in the −4 dB to +4 dB range. The desired response
can be programmed using Subaddress 0xA2. The variation in
frequency responses is shown in Figure 35 to Figure 37.
In addition to the chroma filters listed in Table 43, the ADV7342/
ADV7343 contain an SSAF filter that is specifically designed for
the color difference component outputs, Pr and Pb. This filter
has a cutoff frequency of ~2.7 MHz and a gain of –40 dB at 3.8
MHz (see Figure 62). This filter can be controlled with Subaddress
0x82, Bit 0.
FREQUENCY (MHz)
0
GAIN (dB)
–10
–30
–50
–60
–20
–40
6543210
EXTENDED (SSAF) PrPb FILTER MODE
06399-066
Figure 62. PrPb SSAF Filter
If this filter is disabled, one of the chroma filters shown in
Table 44 can be selected and used for the CVBS or luma/
chroma signal.
Table 44. Internal Filter Specifications
Filter
Pass-Band
Ripple (dB)
1
3 dB Bandwidth (MHz)
2
Luma LPF NTSC 0.16 4.24
Luma LPF PAL 0.1 4.81
Luma Notch NTSC 0.09 2.3/4.9/6.6
Luma Notch PAL 0.1 3.1/5.6/6.4
Luma SSAF 0.04 6.45
Luma CIF 0.127 3.02
Luma QCIF Monotonic 1.5
Chroma 0.65 MHz Monotonic 0.65
Chroma 1.0 MHz
Monotonic
1
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.
D