ADV7321KSTZ Analog Devices Inc, ADV7321KSTZ Datasheet - Page 55

• Manufacturer Part Number: ADV7321KSTZ
• Description: IC VID ENC 6-12BIT DAC'S 64LQFP
• Manufacturer: Analog Devices Inc
• Type: Video Encoderr

Specifications of ADV7321KSTZ

• Applications: EVD, DVD, SD/PS/HDTV
• Voltage - Supply, Analog: 2.5V
• Voltage - Supply, Digital: 2.5V
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Input Format: Digital
• Output Format: Analog
• Supply Voltage Range: 2.375V To 2.625V
• Operating Temperature Range: 0°C To +70°C
• Tv / Video Case Style: LQFP
• No. Of Pins: 64
• Msl: MSL 1 - Unlimited
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

HD SHARPNESS FILTER AND ADAPTIVE FILTER
CONTROLS
[Subaddresses 0x20, 0x38 to 0x3D]
There are three filter modes available on the ADV7320/ADV7321:
sharpness filter mode and two adaptive filter modes.
HD Sharpness Filter Mode
To enhance or attenuate the Y signal in the frequency ranges
shown in Figure 73, the HD sharpness filter must be enabled
and the HD adaptive filter enable must be disabled.
To select one of the 256 individual responses, the corresponding
gain values, which range from –8 to +7, for each filter must be
programmed into the HD sharpness filter gain register at
Address 0x20.
HD Adaptive Filter Mode
The HD Adaptive Filter Threshold A, B, and C registers, the
HD Adaptive Filter Gain 1, 2, and 3 registers, and the HD
sharpness gain register are used in adaptive filter mode. To
activate the adaptive filter control, the HD sharpness filter
and the HD adaptive filter must be enabled.
SIGNAL
INPUT
STEP

1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
FILTER A RESPONSE (Gain K
FREQUENCY (MHz)
SHARPNESS AND ADAPTIVE FILTER CONTROL BLOCK
Figure 73. Sharpness and Adaptive Filters Control Block
A
)
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
Rev. A | Page 55 of 88
FILTER B RESPONSE (Gain K
FREQUENCY (MHz)
The derivative of the incoming signal is compared to the three
programmable threshold values: HD Adaptive Filter Threshold
A, B, and C. The recommended threshold range is from 16 to
235, but any value between 0 and 255 can be used.
The edges can then be attenuated with the settings in the HD
Adaptive Filter Gain 1, 2, and 3 registers, and HD sharpness
filter gain register.
According to the settings of the HD adaptive filter mode
control, there are two adaptive filter modes available:
•
•
Mode A is used when adaptive filter mode is set to 0. In
this case, Filter B (LPF) is used in the adaptive filter block.
Also, only the programmed values for Gain B in the HD
sharpness filter gain and HD Adaptive Filter Gain 1, 2, and
3 are applied when needed. The Gain A values are fixed
and cannot be changed.
Mode B is used when adaptive filter mode is set to 1.
In this mode, a cascade of Filter A and Filter B is used.
Settings for Gain A and Gain B in the HD sharpness filter
gain and HD Adaptive Filter Gain 1, 2, and 3 become
active when needed.
B
)
1.6
1.5
1.4
1.3
1.2
1.1
1.0
FREQUENCY RESPONSE IN SHARPNESS
0
FILTER MODE WITH K
2
FREQUENCY (MHz)
4
ADV7320/ADV7321
6
A
8
= 3 AND K
10
B
12
= 7