GENNUM EB-RD35

GENLINX™ II
EB-RD35 Evaluation Board
PRELIMINARY
LEDs and a LOCK LED which is provided to visually
indicate when the reclocker has locked to the incoming
video signal.
INTRODUCTION
The EB-RD35 is an evaluation and reference design
platform for Routing and Distribution applications using the
GENLINX™ II GS9024 Equalizer, the GS9035 Reclocker,
and the GS9028 Cable Driver.
The reclocked data signals are then supplied to the
GS9028 cable driver which provides two complementary
data outputs at BNC connectors J4 and J5. The GS9028
is configured to drive 75Ω co-axial cables with SMPTE
defined 800mV levels.
CIRCUIT DESCRIPTION
A functional block diagram is shown below and illustrates
the primary circuit functions. These include equalization,
reclocking, and driving 75Ω co-axial cables. A complete
schematic is also included.
BOARD SET-UP AND TEST
The board is configured in SMPTE, auto-tune mode and
supports five data rates: 143Mb/s, 177Mb/s, 270Mb/s,
360Mb/s, and 540Mb/s. LED indicators are used to indicate
when the device is LOCKed and the detected data rate as
shown below:
The EB-RD35 accepts a serial digital data input signal
which first goes into the GS9024 equalizer. Equalization
of the input signal is completely automatic for signal
attenuation due to cable length from 0dB to in excess of
30dB. The signal strength/carrier detect output of the
equalizer, which is proportional to the amount of equalization
taking place, is available via test point TP3. Also available
as an output, is the equalizer "Output Eye Monitor" signal
via a SMA connector (J6). The signal strength/carrier
detect and Output Eye Monitor are useful diagnostic
outputs.
143Mb/s
177Mb/s
270Mb/s
360Mb/s
540Mb/s
GS9024
EQUALIZER
SS1
0
0
1
1
0
SS0
0
1
0
1
0
The GS9035 can also be configured for manual mode by
first putting the AUTO/MANUAL jumper (JMP2) into the 23 position. Then jumpers JMP[7:5] are set accordingly.
After equalization, the differential data signal is passed
to the GS9035 reclocker which generates clock and
retimed data signals. In addition, the complementary
serial clock output signals are available at BNC connectors
J2 and J3. The GS9035 also drives data rate indication
SERIAL
DATA
INPUT
SS2
0
0
0
0
1
Note that whenever the AUTO/MANUAL input of the GS9035
is HIGH (auto mode), jumpers JMP[7:5] should be left
floating to avoid bus contention.
GS9028
CABLE
DRIVER
GS9035
RECLOCKER
SERIAL
DATA
OUTPUTS
SERIAL
CLOCK
OUTPUTS
EB-RD35 BLOCK DIAGRAM
Document No. VB2930 - 1
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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.
BNC connectors and from underneath the output components 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.
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 compliant 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:
- 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.
- Copper on the power and ground planes has been removed from underneath the loop filter and RVCO components of the GS9035. The purpose of these cutouts is to avoid
any noise coupling from the planes into the GS9035.
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 amplifier for serial digital video signals.
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 constructed of standard FR-4 material and measures approximately 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 ensuring maximum signal integrity
- Copper on the power and ground planes has been removed from the area surrounding the center pin of the output
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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