ADV7129KS AD [Analog Devices], ADV7129KS Datasheet - Page 9

• Manufacturer Part Number: ADV7129KS
• Description: 192-Bit, 360 MHz True-Color Video DAC with Onboard PLL
• Manufacturer: AD [Analog Devices]

Mnemonic
IOR, IOG, IOB
IOR, IOG, IOB
R
G
B
R
R
G
B
SENSE/SYNCOUT
V
V
GND
REV. 0
COMP
COMP
RSET,
BIAS
BIAS
REF
AA
COMP
BIAS
R
GSET,
R
BSET
Function
Red, Green & Blue Current Outputs (High Impedance Current Sources). These RGB video outputs are
specified to directly drive RS-343A and RS-170 video levels into doubly terminated 50
Differential Red, Green & Blue Current Outputs (High Impedance Current Sources). These RGB video
outputs are specified to directly drive RS-343A and RS-170 video levels into doubly terminated 50
75
Red Compensation pin. This pin should be bypassed to V
Green Compensation pin. This pin should be bypassed to V
Blue Compensation pin. This pin should be bypassed to V
DAC Output Full-Scale Adjust Control (Analog Input): A resistor from this pin to ground sets the current
in the DACs. The current in the DACs is set according to the equations:
To generate RS 343-A video levels on the DAC outputs, a resistor value of 280
doubly terminated 50
of SYNC and pedestal are possible provided that the maximum DAC current and the DAC output compli-
ance specifications are adhered to.
For example, in a doubly terminated 50
an R
This example would give a 6 dB reduction in noise and feedthrough on the DAC outputs (compared to a
0.7 V full-scale value), but may require a 0.5X splitter at the monitor.
Red Bias node. This node should be decoupled to V
Green Bias node. This node should be decoupled to V
Blue Bias node. This node should be decoupled to V
Comparator Sense Output (TTL Compatible Output). This output will be logic “1” if one or more of the
analog outputs exceeds the internal voltage of the SENSE comparator circuit. It can be used to determine
the absence of a CRT monitor. The value of the SENSE Output corresponds to the current pixel at the out-
puts. The output can drive one CMOS load. This pin can alternately be programmed to be a TTL sync
output which is a delayed version of CSYNC.
Voltage Reference (Analog Input/Output): This should always have a 0.1 F decoupling capacitor attached
between V
ence. If it is required to use a more accurate reference, then this pin acts as an overdrive input. An external
1.235 V voltage reference such as the AD1580 or equivalent is recommended to drive this input. (Note: It is
not recommended to use a resistor network to generate the voltage reference.)
Power Supply (+5 V
to one common +5 V filtered analog power supply.
Analog Ground. The part contains multiple ground pins, all should be connected together to the system’s
ground plane.
SET
loads. If the complementary outputs are not required, then these outputs should be tied to GND.
value of 280
REF
and V
AA
I
OUT
. If nothing else is connected then the DACs are driven by the internal voltage refer-
I
5%). The part contains multiple power supply pins, all should be connected together
OUT
gives a DAC full-scale output of 52.8 mA, i.e., a white-to-black value of 1.4 V.
lines. Any combination of R
= 12,950
= 18,137
V
REF
V
–9–
REF
/R
system with no SYNC or pedestal encoded on the DAC outputs,
/R
SET
SET
(SYNC not encoded on the DAC Output)
(SYNC encoded on the DAC Output)
SET
AA
AA
AA
with a 0.01 F capacitor.
with a 0.01 F capacitor.
value, DAC termination resistor and programming
with a 0.01 F capacitor.
AA
AA
AA
with 0.01 F capacitor.
with 0.01 F capacitor.
with 0.01 F capacitor.
is recommended for
or 75
ADV7129
loads.
or