EVAL-ADV7314EB Analog Devices Inc, EVAL-ADV7314EB Datasheet - Page 48

• Manufacturer Part Number: EVAL-ADV7314EB
• Manufacturer: Analog Devices Inc

Specifications of EVAL-ADV7314EB

• Lead Free Status / Rohs Status: Not Compliant

ADV7314
PROGRAMMABLE DAC GAIN CONTROL
DACs A, B, and C are controlled by Register 0A.
DACs D, E, and F are controlled by Register 0B.
The I
down from its absolute level.
In case A, the video output signal is gained. The absolute level
of the sync tip and blanking level both increase with respect to
the reference video output signal. The overall gain of the
signal is increased from the reference signal.
700mV
300mV
700mV
300mV
CASE A
CASE B
2
Figure 39. Programmable DAC Gain—Positive
and Negative Gain
C control registers will adjust the output signal gain up or
GAIN PROGRAMMED IN DAC O/P LEVEL
REGISTERS, SUBADDRESS 0Ah, 0Bh
NEGATIVE GAIN PROGRAMMED IN
DAC OUTPUT LEVEL REGISTERS,
SUBADDRESS 0Ah, 0Bh
–48–
In case B, the video output signal is reduced. The absolute
level of the sync tip and blanking level both decrease with respect
to the reference video output signal. The overall gain of the signal
is reduced from the reference signal.
The range of this feature is specified for ± 7.5% of the nominal
output from the DACs. For example, if the output current of
the DAC is 4.33 mA, the DAC tune feature can change this
output current from 4.008 mA (–7.5%) to 4.658 mA (+7.5%).
The reset value of the vid_out_ctrl registers is 00h –> nominal
DAC output current. Table XI is an example of how the output
current of the DACs varies for a nominal 4.33 mA output current.
Register
0Ah or 0Bh
0100 0000 (40h)
0011 1111 (3Fh)
0011 1110 (3Eh)
...
...
0000 0010 (02h)
0000 0001 (01h)
0000 0000 (00h)
1111 1111 (FFh)
1111 1110 (FEh)
...
...
1100 0010 (C2h)
1100 0001 (C1h)
1100 0000 (C0h)
DAC
Current
(mA)
4.658
4.653
4.648
...
...
4.43
4.38
4.33
4.25
4.23
...
...
4.018
4.013
4.008
Table XI.
% Gain
7.5000
7.3820
7.3640
...
...
0.0360
0.0180
0.0000
–0.0180
–0.0360
...
...
–7.3640
–7.3820
–7.5000
(I
Nominal)
2
C Reset Value,
REV. 0