GS1574 Data Sheet
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 GS1574 input components to
minimize parasitic capacitance.
The PCB ground plane is removed under the GS1574 output components to
minimize parasitic capacitance.
High speed traces are curved to minimize impedance changes.
5.2 Typical Application Circuit A
MUTE
VCC_A
VCC
14
15
16
13
10n
10n
SDI
6.2n*
1
12
11
10
+
4u7
VEE_D
SDO
VEE_A
SDO
SDO
1u
1u
2
SDI
75
GS1574
3
+
SDI
SDO
4
9
VEE_D
VEE_A
4u7
75
37.5
6
8
5
7
MCLADJ
BYPASS
+
1u
NOTE: All resistors in Ohms, capacitors in Farads,
and inductors in Henrys, unless otherwise noted.
* Value dependent on layout
Figure 5-1: GS1574 Typical Application Circuit
28854 - 5 May 2007
13 of 18
GENNUM [ GENNUM CORPORATION ]
