GV8500 Datasheet, PDF (9/13 Pages) Semtech Corporation – Pb-free and RoHS compliant

5. Application Information
5.1 PCB Layout
Special attention must be paid to component layout when designing serial digital
interfaces for HDcctv.
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 1.485Gb/s data rate signals is closely matched to SMT
component width to minimize reflections due to changes in trace impedance
• The PCB ground plane is removed under the GV8500 output components to
minimize parasitic capacitance
• The PCB ground plane is removed under the GV8500 R_SET pin and resistor to
minimize parasitic capacitance
• 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
5.2 Typical Application Circuit
Differential
Data Input
4u7
49.9
10n
49.9
4u7 _VCC
750
DISABLE
SD/HD
GV8500
1
2
3
4
6
DDI
DDI
VEE
RSET
DISABLE
SDO
SDO
SD/HD
VCC
12
11
10
9
VCC
10n
NOTE: All resistors in Ohms, capacitors in Farads,
and inductors in Henrys, unless otherwise noted.
Figure 5-1: Typical Application Circuit
5.6n*
75
VCC
75
75
4u7
10n
75
5.6n*
4u7
BNC
BNC
*Typical value: varies with layout
GV8500 Aviia™ Cable Driver
Data Sheet
57076 - 1
April 2012
9 of 13