ADV7120KN30 Analog Devices, ADV7120KN30 Datasheet - Page 10

• Manufacturer Part Number: ADV7120KN30
• Description: CMOS 80 MHz/ Triple 8-Bit Video DAC
• Manufacturer: Analog Devices

ADV7120
PC BOARD LAYOUT CONSIDERATIONS
The ADV7120 is optimally designed for lowest noise perfor-
mance, both radiated and conducted noise. To complement the
excellent noise performance of the ADV7120, it is imperative
that great care be given to the PC board layout. Figure 8 shows
a recommended connection diagram for the ADV7120.
The layout should be optimized for lowest noise on the
ADV7120 power and ground lines. This can be achieved by
shielding the digital inputs and providing good decoupling. The
lead length between groups of V
minimized so as to minimize inductive ringing.
INPUTS
CONTROL
VIDEO
DATA
INPUTS
VIDEO
CLOCK
R0
R7
G0
G7
B0
B7
REF WHITE
BLANK
SYNC
COMPONENT
C3, C4, C5, C6
Figure 8. ADV7120 Typical Connection Diagram and Component List
ADV7120
R1, R2, R3
AA
L1, L2
and GND pins should by
Rset
FS ADJUST
SET
SET
C1
C2
Z1
COMP
I
SYNC
V
GND
IOR
IOG
IOB
V
REF
AA
DESCRIPTION
33 F TANTALUM CAPACITOR
10 F TANTALUM CAPACITOR
0.1 F CERAMIC CAPACITOR
FERRITE BEAD
75 1% METAL FILM RESISTOR
560 1% METAL FILM RESISTOR
1.235V VOLTAGE REFERENCE
R
560
SET
C6
0.1 F
C3
0.1 F
75
R1
ANALOG POWER PLANE
–10–
C4
0.1 F
75
R2
Ground Planes
The ADV7120 and associated analog circuitry, should have a
separate ground plane referred to as the analog ground plane.
This ground plane should connect to the regular PCB ground
plane at a single point through a ferrite bead, as illustrated in
Figure 8. This bead should be located as close as possible
(within 3 inches) to the ADV7120.
The analog ground plane should encompass all ADV7120
ground pins, voltage reference circuitry, power supply bypass
circuitry, the analog output traces and any output amplifiers.
The regular PCB ground plane area should encompass all the
digital signal traces, excluding the ground pins, leading up to
the ADV7120.
VENDOR PART NUMBER
FAIR-RITE 274300111 OR MURATA BL01/02/03
DALE CMF-55C
DALE CMF-55C
ANALOG DEVICES AD589JH
75
R3
C5
0.1 F
ANALOG GROUND PLANE
Z1 (AD589)
C2
10 F
L1 (FERRITE BEAD)
L2 (FERRITE BEAD)
RGB
VIDEO
OUTPUT
C1
33 F
+5V (V
GROUND
REV. B
CC
)