Design Guideline - Advantech SOM-ETX Series Design Manual

Advantech SOM-ETX Design Guide

5.12.2 Design Guideline

5.12.2.1 Termination resistor , output filter and ESD protection
diodes of TV DAC output
There are four DAC output pins: DACA (COMP), DACB (C), DACC (Y), and DACD
(TVSYNC). The components associated with these pins should be placed as close
as possible to the TV encoders . The 75 ohm 1% output termination, output filter
network are implemented at SOM-ETX module. To minimize the hazard of ESD from
discharge of TV, a set of protection diodes (like BAT54S) is strongly recommended to
use for each DAC output. This ESD protection diodes (like BAT54S) also be
implemented at SOM-EXT and do not need to be considered in carried board.
The video output signals should overlay the ground plane and be separated by a
ground trace, inductors and ferrite beads in series.
Figure 5-37 Two Composite and One S-Video Outputs\
Chapter 5 Carrier Board Design Guidelines 103