5. Application Information
5.1 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:
•
•
•
•
PCB trace width for HD rate signals is closely matched to SMT component width to
minimize reflections due to change in trace impedance.
The PCB ground plane is removed under the GS1524A input components to
minimize parasitic capacitance.
The PCB ground plane is removed under the GS1524A output components to
minimize parasitic capacitance.
High speed traces are curved to minimize impedance changes.
5.2 Typical Application Circuits
CLI
CD/MUTE
VCC
10n
VCC
10n
GS1524A
BNC
6.4n
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
CLI
CD/MUTE
VCC
+ 4u7
VCC
VEE
SDI
1u
VEE
SDO
SDO
75
SDO
+
SDO
SDI
1u
VEE
AGC+
AGC-
VEE
MCLADJ
BYPASS
4u7
75
37.4
+
1u
MCLADJ
BYPASS
NOTE: All resistors in Ohms, capacitors in Farads,
and inductors in Henrys, unless otherwise noted.
Figure 5-1: GS1524A Typical Application Circuit
GS1524A Adaptive Cable Equalizer
Data Sheet
13 of 16
28852 - 5
June 2009
GENNUM [ GENNUM CORPORATION ]
