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ADV101
–5–
REV. B
PIN FUNCT ION DE SCRIPT ION
Pin
Mnemonic
Function
BLANK
Composite blank control input (T T L compatible). A logic zero on this control input drives the analog outputs,
IOR, IOB and IOG, to the blanking level. T he
BLANK
signal is latched on the rising edge of CLOCK . While
BLANK
is a logical zero, the R0–R7, G0–G7, R0–R7 and REF WHIT E pixel and control inputs are ignored.
Composite sync control input (T T L compatible). A logical zero on the
SYNC
input; switches off a 40 IRE cur-
rent source on the I
SYNC
output.
SYNC
does not override any other control or data input, therefore, it should
only be asserted during the blanking interval.
SYNC
is latched on the rising edge of CLOCK .
Clock input (T T L compatible). T he rising edge of CLOCK latches the R0–R7, G0–G7, B0–B7,
SYNC
,
BLANK
and REF WHIT E pixel and control inputs. It is typically the pixel clock rate of the video system.
CLOCK should be driven by a dedicated T T L buffer.
Reference white control input (T T L compatible). A logical one on this input forces the IOR, IOG and IOB out-
puts to the white level, regardless of the pixel input data (R0–R7, G0–G7 and B0–B7) REF WHIT E is latched
on the rising edge of clock.
Red, green and blue pixel data inputs (T T L compatible). Pixel data is latched on the rising edge of CLOCK . R0,
G0 and B0 are the least significant data bits. Unused pixel data inputs should be connected to either the regular
PCB power or ground plane.
Red, green and blue current outputs. T hese high impedance current sources are capable of directly driving a
doubly terminated 75
coaxial cable. All three current outputs should have similar output loads whether or not
they are all being used.
Sync current output. T his high impedance current source can be directly connected to the IOG output. T his al-
lows sync information to be encoded onto the green channel. I
SYNC
does not output any current while
SYNC
is
at logical zero. T he amount of current output at I
SYNC
while
SYNC
is at logical one is given by:
I
SYNC
(mA) = 3,455
×
V
REF
(V)/R
SET
(
)
If sync information is not required on the green channel, I
SYNC
should be connected to AGND.
Full-scale adjust control. A resistor (R
SET
) connected between this pin and GND, controls the magnitude of the
full-scale video signal. Note that the IRE relationships are maintained, regardless of the full-scale output current.
T he relationship between R
SET
and the full-scale output current on IOG (assuming I
SYNC
is connected to IOG)
is given by:
R
SET
(
) = 12,082
×
V
REF
(
V
)
/IOG (mA)
T he relationship between R
SET
and the full-scale output current on IOR and IOB is given by:
IOR, IOB (mA) =
8,628
×
V
REF
(
V
)
/ R
SET
(
)
Compensation pin. T his is a compensation pin for the internal reference amplifier. A 0.1
μ
F ceramic capacitor
must be connected between COMP and V
AA
.
Voltage reference input. An external 1.2 V voltage reference must be connected to this pin. T he use of an exter-
nal resistor divider network is not recommended. A 0.1
μ
F decoupling ceramic capacitor should be connected
between V
REF
and V
AA
.
Analog power supply (5 V
±
5%). All V
AA
pins on the ADV101 must be connected.
Ground. All GND pins must be connected.
SYNC
CLOCK
REF WHIT E
R0–R7,
G0–G7,
B0–B7
IOR, IOG, IOB
I
SYNC
FS ADJUST
COMP
V
REF
V
AA
GND