User’s Guide
July 2000 AAP Data Transmission
SLLU013
About This Manual
Trademarks
Preface
Read This First
This is the user’s guide for the SN65LVDS387EVM and SN65LVDS386 evaluation modules (EVMs). It contains information on the evaluation modules
(EVMs) for T exas Instruments’ SN65L VDS387 16-channel LVDS driver and for
the SN65L VDS386 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 L VDS inputs of the 16-channel L VDS 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.
Read This First
iii
Running 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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Title—Attribute Reference
v
Running Title—Attribute Reference
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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
vi
Chapter 1
Introduction
This is the user’s guide for the evaluation modules (EVMs) for the Texas Instruments’ SN65LVDS387EVM 16-channel LVDS driver EVM and the
SN65L VDS386EVM 16-channel LVDS 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 transmission begin to outweigh the cost advantages of single-ended techniques when
signal-transition times approach 10 nS. This represents signaling rates approaching 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, respectively), 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: T o 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.
Introduction
1-1
Chapter 2
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 L VDS Line Driver 2-3. . . . . . . . . . . . . . . . . . . .
2.2 SN65L VDS386 16-Channel LVDS Line Receiver 2-5. . . . . . . . . . . . . . . . . .
The Evaluation Boards
2-1
Figure 2–1.EVM Simplified I/O Block Diagram
L VTTL Input
Connector
EN_A
A1A
A2A
A3A
51
GND VCCGND
V
CC
LVDS Output
Connector
A1Y
A1Z
A2Y
A2Z
A3Y
A3Z
L VTTL Output
Connector
EN_A
D4Y
D3Y
D2Y
100
L VDS Input
Connector
D4B
D4A
D3B
D3A
D2B
D2A
A4A
LVDS Driver
(1 of 4)
L VDS387EVM
The SN65LVDS387EVM and the SN65LVDS386EVM are discussed in sections 2.1 and 2.2. Use of the schematics in Appendix A will facilitate understanding the detailed discussion that follows.
A4Y
A4Z
D1Y
LVDS Receiver
(1 of 4)
L VDS386EVM
D1B
D1A
2-2
SN65LVDS387 16-Channel LVDS Line Driver
2.1 SN65LVDS387 16-Channel LVDS Line Driver
This 16-channel L VDS driver accepts 16 low-voltage TTL (L VTTL) inputs and
generates 16 LVDS differential outputs (please refer to the schematic in
Appendix I). Connectors P1/P2 are the L VTTL I/O connectors. Connectors P3
through P7 are the L VDS 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 L VTTL input line to
accommodate inputs from a pattern generator or other instrumentation that
has a 50-Ω source impedance. If the LVTTL source and cable being used is
not a 50-Ω source, then these resistors (resistors R33 through R48) need to
be removed. They are required to match the characteristic impedance of the
cable (and the source impedance of most pattern generators). These resistors
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 SN65L VDS387EVM. These are used in the
L VDS output circuit and, since L VDS lines are normally terminated at the input
to the receiver, these 100-Ω resistors 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 L VTTL
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 fourchannel (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 V
and GND. The jumper short can be moved
CC
so contact is made between VCC and the enable/disable pin, or between GND
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.
The Evaluation Boards
2-3
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