Texas Instruments SN65LVDS387EVM User manual

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July 2000 AAP Data Transmission
User’s Guide
SLLU013

Trademarks
iii
Read This First
Preface
Read This First
About This Manual
Thisistheuser’sguidefortheSN65LVDS387EVMandSN65LVDS386evalu-
ation modules (EVMs). It contains information on the evaluation modules
(EVMs)forTexasInstruments’SN65LVDS38716-channelLVDSdriverandfor
the SN65LVDS386 16-channel LVDS receiver.
Two separate EVMs are available, allowing each LVDS device to be tested
individually using a single EVM for that device. If both EVMs are used, the
LVDS output signals from the SN65LVDS387EVM 16-channel LVDS driver
can be connected to the LVDS inputs of the 16-channel LVDS receiver on the
SN65LVDS386EVM. This allows users to simulate performance of an LVDS
system. Recommended test equipment and evaluation and interconnect
guidelines are provided for both 16-channel point-to-point and multidrop
configurations. The EVMs are CE compliant for distribution within the
European Community.
How to Use This Manual
This document contains the following chapters:
Chapter 1 – Introduction
Chapter 2 – The Evaluation Boards
Chapter 3 – Equipment Required
Chapter 4 – Operation
Appendix A – Parts List and Schematics
Trademarks
BergStick is a registered trademark of Berg Electronics. All other trademarks
are the property of their respective owners.

Running Title—Attribute Reference
v
Chapter Title—Attribute Reference
Contents
1 Introduction 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 The Evaluation Boards 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 SN65LVDS387 16-Channel LVDS Line Driver 2-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 SN65LVDS386 16-Channel LVDS Line Receiver 2-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Equipment Required 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Pattern Generator 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Oscilloscope and Scope Probes 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Power Supply 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 Cables 3-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Operation 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1 SN65LVDS387 Operation 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 SN65LVDS386 Operation 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 System Evaluation Using Both the SN65LVDS387EVM and SN65LVDS386EVM 4-3. . . .
4.3.1 Point-to-Point Configuration 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3.2 Multidrop Configuration 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4 References 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A Parts List and Schematics A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.1 Parts List for EVMs A-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2 Schematic Diagrams 6420201 and 6420202 A-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Running Title—Attribute Reference
vi
Figures
2–1. EVM Simplified I/O Block Diagram 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–2. SN65LVDS387EVM 2-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–3. SN65LVDS386EVM 2-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4–1. Examples of Multidrop Interconnections 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1
Introduction
Introduction
Thisistheuser’sguidefortheevaluationmodules(EVMs)fortheTexasInstru-
ments’ SN65LVDS387EVM 16-channel LVDS driver EVM and the
SN65LVDS386EVM16-channelLVDS receiver EVM. One manual is used for
both EVMs because the boards are similar for both devices. The EVMs are
CE-compliant for distribution within the European Community.
Low-voltage differential signaling (LVDS), as documented in TIA/EIA-644, is
a balanced signaling method used for high-speed transmission of binary data
over copper. It is well recognized that the benefits of balanced-data transmis-
sion begin to outweigh the cost advantages of single-ended techniques when
signal-transition times approach 10 nS. This represents signaling rates ap-
proaching 30 Megabits per second (Mbps) Presently, LVDS devices operate
with signaling rates in the hundreds of Mbps. This performance is achieved
with reduced power consumption and reduced electromagnetic interference
(EMI) emissions compared to other data transmission standards, such as
TIA/EIA–422 and TIA/EIA–232 (also known as RS–232 and RS–422, respec-
tively), PECL, etc. Project collateral discussed in this user’s guide can be
downloaded from the following URL: http://www.ti.com/lit/zip/SLLU013.
Note: To Designers
Both EVMs use the same printed-wiring board (PWB). The 387 device is
mounted with the device’s pin 1 facing the top of the PWB, and the 386 is
mounted with the device’s pin 1 facing the bottom of the PWB.
Chapter 1

2-1
The Evaluation Boards
The Evaluation Boards
Each EVM consists of a six-layer printed-wiring board (PWB). The LVDS
device and BergStickconnectors are on the top (connector side) of the
board. All other passive components are installed on the underside
(component side) of the PWB. A simplified input/output (I/O) block diagram of
the EVM is shown in Figure 2–1.
Topic Page
2.1 SN65LVDS387 16-Channel LVDS Line Driver 2-3. . . . . . . . . . . . . . . . . . . .
2.2 SN65LVDS386 16-Channel LVDS Line Receiver 2-5. . . . . . . . . . . . . . . . . .
Chapter 2

2-2
Figure 2–1.EVM Simplified I/O Block Diagram
LVTTL Input
Connector
A1A
LVDS387EVM
EN_A
LVDS Output
Connector
A1Z
A1Y
A2A A2Z
A2Y
A3A A3Z
A3Y
A4A A4Z
A4Y
LVDS Driver
(1 of 4)
LVTTL Output
Connector
D4Y
LVDS386EVM
LVDS Input
Connector
D4B
D3Y
D2Y
D1Y
LVDS Receiver
(1 of 4)
VCC GND VCC GND
D4A
EN_A
D3B
D3A
D2B
D2A
D1B
D1A
51 100
The SN65LVDS387EVM and the SN65LVDS386EVM are discussed in sec-
tions 2.1 and 2.2. Use of the schematics in Appendix A will facilitate under-
standing the detailed discussion that follows.

SN65LVDS387 16-Channel LVDS Line Driver
2-3
The Evaluation Boards
2.1 SN65LVDS387 16-Channel LVDS Line Driver
This 16-channel LVDS driver accepts 16 low-voltage TTL (LVTTL) inputs and
generates 16 LVDS differential outputs (please refer to the schematic in
AppendixI).Connectors P1/P2are theLVTTLI/O connectors.Connectors P3
through P7 are the LVDS I/O connectors. The LVTTL inputs can be provided
by any suitable source. As shipped, the SN65LVDS387EVM has 50-Ω
termination resistors (R33 through R48) installed on each LVTTL input line to
accommodate inputs from a pattern generator or other instrumentation that
has a 50-Ωsource impedance. If the LVTTL source and cable being used is
not a 50-Ωsource, then these resistors (resistors R33 through R48) need to
be removed. They are required to match the characteristic impedance of the
cable(andthesourceimpedanceofmostpatterngenerators).Theseresistors
are located on the back (under) side of the SN65LVDS386EVM, next to the
P1/P2 connector row.
The other optional components are resistors R1 through R32. Resistors R1
through R16 are left open on the SN65LVDS387EVM. These are used in the
LVDSoutputcircuitand, sinceLVDSlinesare normallyterminatedattheinput
to the receiver, these 100-Ωresistors are not installed on the EVM. If users
want to measure specific performance parameters on the ’387, then they are
responsible for installing 100-ohm resistors in R1 through R16. Zero-ohm
resistors are installed in R17 through R32, which are in series with the LVTTL
inputs to the SN65LVDS387. The remaining components are connectors for
Vcc and Gnd connections, and decoupling capacitors for the LVDS device.
These components are the same for both configurations of the EVM.
There are also four jumpers (JMP1 through JMP4 ) located next to the P1/P2
connector row. These jumpers control the enable and disable for each four-
channel (quad) section of the device. Each of these jumpers consist of three
pinsandajumpershort.Thecenterpinisconnectedtothedeviceandtheout-
er pins (top and bottom) are VCC and GND. The jumper short can be moved
socontactismadebetweenVCC andtheenable/disablepin,orbetweenGND
and the enable/disable pin. As shipped, the four jumper shorts are installed to
VCC so that all four sections of the device are enabled. A photograph of the
SN65LVDS387EVM is shown is Figure 2–2.

SN65LVDS387 16-Channel LVDS Line Driver
2-4
Figure 2–2.SN65LVDS387EVM
LVTTL
Input Pins
Connector (Top) Side Component (Bottom) Side
GND Enable/Disable
Jumpers LVDS Output Pins
VCC

SN65LVDS386 16-Channel LVDS Line Receiver
2-5
The Evaluation Boards
2.2 SN65LVDS386 16-Channel LVDS Line Receiver
The SN65LVDS386EVM accepts 16 LVDS inputs and generates 16 LVTTL
outputs (refer to the schematic in Appendix I). Connectors P3 through P7
(right-sideedge)acceptthedifferentialLVDSinputsandconnectorP1/P2pro-
vides the LVTTL output signals. The
as shipped configuration of the
SN65LVDS386EVMalsocontainsexternalresistorsrequiredforbasicopera-
tion and testing of the device. Resistors R1 through R16 are 100-Ωresistors
which terminate each LVDS input channel. These are installed on the under-
side of the SN65LVDS386EVM, very close to the input pins of the device.
TheLVTTL output-channelspath (etchon the PWB)contains two
pads where
external resistors may be installed. Resistors R17 through R32 are series re-
sistorswherezero-ohmresistorsarenormallyinstalled.Thesearefollowedby
resistors R33 through R48, which allow a pull-down resistor to be installed af-
ter the series resistor (R17 through R32). As shipped, these pull-down resis-
tors are not installed. The combination of these series (R17 through R32) and
pull-down resistors (R 33 through R48) allow the user to install a divider net-
workifdesired.Thismightbenecessaryiftheoutputsaretobemeasuredwith
aninstrument havinga50-Ωinputimpedance. Byinstallinga 475-Ωseriesre-
sistor and a 50-Ωpull down resistor, a 20:1 divider is created (the 50-Ωpull-
down in parallel with the 50-Ωinput impedance equals 25 Ω, plus the 475-Ω
series impedance of the instrument, for a total load of 500 Ωon the output of
thereceiver).Asshipped,thereisnoresistordividerinstalled,andeachdevice
LVTTLoutputis routeddirectly totheP1/P2connectors througha0-Ωresistor
(R17 through R32).
The remaining components are connectors for VCC and GND connections,
and decoupling capacitors for the LVDS device (these components are the
same for both EVM configurations).
There are also four jumpers (JMP1 through JMP4 ) located next to the P1/P2
connector row. These jumpers control the enable/disable for each four-chan-
nel (quad) section of the device. Each of these jumpers consist of three pins
and a jumper short. The center pin is connected to the device and the outer
pins (top and bottom) are VCC and GND. The jumper short can be moved so
contact is made between VCC and the enable/disable pin, or between GND
andtheenable/disable pin.As shipped,the jumpershortsareinstalled toVCC
so that all four sections of the device are enabled.