GS1528 Data Sheet
4. Application Information
4.1 PCB Layout
Special attention must be paid to component layout when designing serial digital
interfaces for HDTV. An FR-4 dielectric can be used, however, controlled
impedance transmission lines are required for PCB traces longer than
approximately 1cm. Note the following PCB artwork features used to optimize
performance:
The PCB trace width for HD rate signals is closely matched to SMT component
width to minimize reflections due to changes in trace impedance.
The PCB groundplane is removed under the GS1528 output components to
minimize parasitic capacitance.
The PCB ground plane is removed under the GS1528 R
minimize parasitic capacitance.
pin and resistor to
SET
Input and output BNC connectors are surface mounted in-line to eliminate a
transmission line stub caused by a BNC mounting via high speed traces which are
curved to minimize impedance variations due to change of PCB trace width.
4.2 Typical Application Cirucit
*
5.6n
75
BNC
4u7
4u7
GS1528
VCC
49.9
49.9
1
2
3
8
7
6
75
75
SDI
SDI
VEE
SDO
SDO
10n
10n
SD/HD
DIFFERENTIAL
DATA INPUT
75
*
5.6n
BNC
4
5
4u7
4u7
* TYPICAL VALUE VARIES WITH LAYOUT
VCC
VCC
750
10n
SD/HD
NOTE: All resistors in Ohms, capacitors in Farads,
and inductors in Henrys, unless otherwise noted.
16632 - 5 June 2005
11 of 13
GENNUM [ GENNUM CORPORATION ]
