adv473 Analog Devices, Inc., adv473 Datasheet - Page 12

• Manufacturer Part Number: adv473
• Description: Cmos 135 Mhz True-color Graphics Triple 8-bit Video Ram-dac
• Manufacturer: Analog Devices, Inc.

ADV473
Analog Signal Interconnect
The ADV473 should be located as close as possible to the out-
put connectors to minimize noise pickup and reflections due to
impedance mismatch.
The video output signals should overlay the ground plane, and
not the analog power plane, to maximize the high frequency
power supply rejection.
For maximum performance, the analog outputs should each
have a 75
between the current output and GND should be as close as pos-
sible to the ADV473 to minimize reflections.
For more information on circuit board design and layout, see
application note entitled “Design and Layout of a Video Graph-
ics System for Reduced EMI” available from Analog Devices,
Publication No. E1309-15-10/89.
R
140
0.1 F
SET
Figure 8. Typical Connection Diagram (Internal Voltage
Reference)
+5V (V
COMPONENT
C6
L1
R1, R2, R3
R
C1 – C5
SET
AA
)
ADV473
COMP
COMP
R
GND
V
SET
REFOUT
V
V
load resistor connected to GND. The connection
REFIN
AA
IOR
IOG
IOB
ANALOG POWER PLANE
75
DESCRIPTION
0.1 F CERAMIC CAPACITOR
10 F TANTALUM CAPACITOR
FERRITE BEAD
75 1% METAL FILM RESISTOR
1% METAL FILM RESISTOR
0.1 F
75
0.1 F
0.1 F
CO-AXIAL CABLE
75
(75 )
CONNECTORS
POWER SUPPLY DECOUPLING
(0.1 F CAPACITOR FOR
EACH V
BNC
+5V (V
REF
10 F
VENDOR PART NUMBER
ERIE RPE112Z5U104M50V
MALLORY CSR13G106KM
FAIR-RITE 2743001111
75
75
75
GROUP)
AA
)
(FERRITE
BEAD)
MONITOR
L1
(CRT)
+5V (V
0.1 F
CC
)
–12–
Package Thermal Considerations
In certain circumstances, the 135 MHz version of the ADV473
may require forced air cooling or the addition of a heatsink. The
68-pin PLCC has a heat resistance characteristic as shown in
Table VIII.
It should be noted that information on Package Thermal Characteris-
tics published herein may not be the most up to date at the time of
reading this. Advances in packaging technology will inevitably lead
to improvements in thermal data. Please contact your local sales office
for the most up-to-date information.
Air Velocity
(Linear Feet/Min) 0 (Still Air)
JA
10
26
27
( C/W)
9
Table VIII. Thermal Resistance vs. Airflow
0.995 (25.27)
0.885 (22.48)
0.954 (24.23)
0.950 (24.13)
Dimensions shown in inches and (mm).
IDENTIFIER
TOP VIEW
Plastic Leaded Chip Carrier
OUTLINE DIMENSIONS
PIN 1
32
SQ
SQ
(P-68A)
43
61
60
44
50
26
0.175 (4.45)
0.169 (4.29)
0.104 (2.64) TYP
100
19
0.019 (0.48)
0.017 (0.43)
0.029 (0.74)
0.027 (0.69)
0.050
(1.27)
TYP
200
16
0.925 (23.50)
0.895 (22.73)
REV. A