EB-RD35 Datasheet, PDF (2/9 Pages) Gennum Corporation – GENLINX-TM II EB-RD35 Evaluation Board

The CD_ADJ input of the GS9024 is biased via a resistor
network including a potentiometer allowing the user to
adjust the level at which loss of carrier is detected. For a
detailed description of the CD_ADJ voltage level versus
muting threshold refer to the GS9024 data sheet. Turning the
potentiometer completely clockwise allows for maximum
possible cable length equalization. In addition, the GS9024
outputs can be put in a HIGH-Z state by putting jumper JMP1
into the 1-2 position.
To verify operation of the EB-RD35, a source of serial digital
video should be applied to the input BNC connector using
75Ω co-axial cable. Using a signal source that is not compli-
ant to the SMPTE standards, can provide misleading results
for equalizer cable length performance. The output data
stream is available at the serial output and can be supplied
to a D to A converter for verification via a monitor. Note that
the jumpers should be set as shown below for an output to
be present:
JMP1: 2-3 (equalizer outputs enabled)
JMP2: 1-2 (reclocker configured for AUTO mode)
JMP3: 1-2 (reclocker configured for SMPTE mode)
The power supply requirement for the EB-RD35 is +5V for
VCC at a current rating of 230mA (nominally).
PCB DETAILS
The EB-RD35 is a four layer printed circuit board con-
structed of standard FR-4 material and measures approxi-
mately 5" by 4.5". Ground and power plane layers are internal
to the board with signal layers on the top and bottom of the
board. Components are mounted both on the top and
bottom sides. The silkscreen (top and bottom) and all four
layers are shown on the following pages. Note the following
special artwork features used to optimize performance:
- A continuous ground plane is provided underneath all high
speed traces avoiding impedance discontinuities and en-
suring maximum signal integrity
- Copper on the power and ground planes has been re-
moved from the area surrounding the center pin of the output
BNC connectors and from underneath the output compo-
nents of the GS9028 cable driver. The purpose of these
cutouts is to reduce the effect of the capacitance added by
the connector and the pads of the components.
- Copper on the power and ground planes has been re-
moved from underneath the loop filter and RVCO compo-
nents of the GS9035. The purpose of these cutouts is to avoid
any noise coupling from the planes into the GS9035.
- The ground plane associated with the input BNC connector
and input components is isolated from the main board
ground. The purpose of this is to provide a differential input
signal to the equalizer.
APPLICATIONS
The EB-RD35 evaluation board is designed to show the
characteristics of the GS9024 Equailizer, the GS9035
Reclocker, and the GS9028 Cable Driver. This board can
also be used as a stand alone reclocking distribution ampli-
fier for serial digital video signals.
CAUTION
ELECTROSTATIC
SENSITIVE DEVICES
DO NOT OPEN PACKAGES OR HANDLE
EXCEPT AT A STATIC-FREE WORKSTATION
Gennum Corporation assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement.
Please be advised that this preliminary document does not conform to Gennum's ISO9001 standards.
© Copyright March 1998 Gennum Corporation. All rights reserved. Printed in Canada.
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