Anti Alias Filters; Description; Anti Alias Filter Control; Anti Alias Filter Frequency Characteristics - Analog Devices Advantiv ADV7604 Hardware Manual

6.7

Anti Alias Filters

6.7.1 Description

The ADV7604 has optional anti aliasing filters on each of the three input channels. The filters are
designed for SD, ED, and HD video with various bandwidths selectable via I
most effective when ADC oversampling is selected.
The filters can be individually enabled and disabled via I
All filters are disabled when the ADV7604 powers up.

6.7.2 Anti Alias Filter Control

AA_FILT_EN[0], AFE Map, Address 0x05, [0]
Function
AA_FILT_EN[0]
0
1
AA_FILT_EN[1], AFE Map, Address 0x05, [1]
Function
AA_FILT_EN[1]
0
1
AA_FILT_EN[2], AFE Map, Address 0x05, [2]
Function
AA_FILT_EN[2]
0
1

6.7.3 Anti Alias Filter Frequency Characteristics

AA_FILT_PROG_BW[1:0], AFE Map, Address 0x07, [6:5]
AA_FILT_HIGH_BW[1:0], AFE Map, Address 0x06, [5] and Address 0x07,[7]
AA_FILT_PROG_BW[1:0] combined with the AA_FILT_HIGH_BW[1:0] bits control the anti
alias filter response to be selected. The chosen response is applied to all three AA filters
simultaneously. Table 15
frequency (Fc) is also shown in the table. All possible filter responses are shown in
AA_FILT_HIG_BW[1:0] AA_FILTER_PROG_BW[1:0]
[1]
Rev. F August 2010
Description
Disables anti aliasing filter on channel 0
Enables anti aliasing filter on channel 0
Description
Disables anti aliasing filter on channel 1
Enables anti aliasing filter on channel 1
Description
Disables anti aliasing filter on channel 2
Enables anti aliasing filter on channel 2
shows how to choose the various filter characteristics. The 3 db cutoff

Table 15: Anti Alias Filter Frequency Characteristics

[0] [1]
2
C under the control of AA_FILT_EN[2:0].
[0]
88
ADV7604
2
C. These filters are
Figure 18.
Fc Frequency
(MHz) Response
No