National Semiconductor DS91C176EVK NOPB User Manual
RJ45 to SMA Adapter Board
USER MANUAL
Part Number: DS91C176EVK NOPB
For the latest documents concerning these products and evaluation kit, visit lvds.national.com.
Schematics and gerber files are also available at lvds.national.com.
January 2008
Rev. 0.1
DS91C176EVK User Manual
Table of Contents
Table of Contents..................................................................................................................... 2
Overview................................................................................................................................... 3
Board Description..................................................................................................................... 4
Configuration Instructions......................................................................................................... 5
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DS91C176EVK User Manual
Overview
The DS91C176EVK consists of two RJ45 to SMA adapter boards developed to complement
National Semiconductor’s evaluation boards for which evaluation with CAT5e cable assembli es is
sometimes desirable (e.g. DriveCable02EVK, LVDS-18B-EVK, DS25BR100EVK, etc.).
In addition, each adapter board features a single DS91C176, an M-LVDS transceiver with Type 2
receiver inputs for optional passing of slow “control” signals over one of the twisted pairs of a
twisted pair cable.
Figure 1. Photo of the RJ45 to SMA Adapter Board
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DS91C176EVK User Manual
Board Description
Figure 2 shows the adapter board drawing with the silkscreen annotations. The 2.5 by 3.0 inch,
four-layer PCB is designed to bring RJ45 connector signal pins to SMA connectors. The SMA
connector annotations correspond to the RJ45 connector pin numbers. There are only 2 SMA
pairs installed (1&2 and 7&8) on the board. The end user may install additional SMA connectors.
One of the RJ45 connector signal pin pairs (3 and 6) are connected to DS91C176 (U1) M-LV DS
I/O pins. There is a provision to disconnect the DS91C176 M-LVDS pins and connect the SMA
connectors (3 and 6).
The JP2 and JP3 connectors connect to the DS91C176 LVCMOS I/O and control pins.
2.5 INCHES
21
GND
4
VDD
5
7
8
36
0.625 INCHES
Figure 2. DS91C176EVK Drawing
J1
J2
JP1
VDD
SIG
GND
RD
SIG
GND
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DS91C176EVK User Manual
User Instructions
This section provides adapter board user instructions:
1. It is always recommended to terminate unused twisted pairs of a twisted pair cable to
minimize EMI, crosstalk, etc., thus termination resistors R6, R7 and R8. Remove
resistors connected to the RJ45 pins that you plan to use. For example, remove R7 if
you plan to use RJ45 pins 1 and 2 (they are connected to SMA1 and SMA2 connectors
respectively).
2. If you want to use RJ45 pins 3 and 6 (they are connected to SMA3 and SMA6 connector
pads respectively), disconnect the DS91C176 (U1) M-LVDS pins by removing R2 and R3
0-ohm resistors and placing them on the R4 and R5 resistor pads.
3. If you want to use the DS91C176 (U1), apply 3.3 V between the VDD (J2) and GND (J1)
power connectors, configure the device as an M-LVDS driver or receiver using the JP3
and use the JP2 to access the DS91C176 LVCMOS I/O pins. For more info on the
DS91C176 check its respective datasheet at lvds.national.com.
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