SLLS373M July   1999  – March 2024 SN65LVDS1 , SN65LVDS2 , SN65LVDT2

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Options
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Driver Electrical Characteristics
    6. 6.6 Receiver Electrical Characteristics
    7. 6.7 Driver Switching Characteristics
    8. 6.8 Receiver Switching Characteristics
    9. 6.9 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 SN65LVDS1 Features
        1. 8.3.1.1 Driver Output Voltage and Power-On Reset
        2. 8.3.1.2 Driver Offset
        3. 8.3.1.3 5-V Input Tolerance
        4. 8.3.1.4 NC Pins
        5. 8.3.1.5 Driver Equivalent Schematics
      2. 8.3.2 SN65LVDS2 and SN65LVDT2 Features
        1. 8.3.2.1 Receiver Open Circuit Fail-Safe
        2. 8.3.2.2 Receiver Output Voltage and Power-On Reset
        3. 8.3.2.3 Common-Mode Range vs Supply Voltage
        4. 8.3.2.4 General Purpose Comparator
        5. 8.3.2.5 Receiver Equivalent Schematics
        6. 8.3.2.6 NC Pins
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation With VCC < 1.5 V
      2. 8.4.2 Operation With 1.5 V ≤ VCC < 2.4 V
      3. 8.4.3 Operation With 2.4 V ≤ VCC < 3.6 V
      4. 8.4.4 SN65LVDS1 Truth Table
      5. 8.4.5 SN65LVDS2 and SN65LVDT2 Truth Table
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Point-to-Point Communications
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Driver Supply Voltage
          2. 9.2.1.2.2  Driver Bypass Capacitance
          3. 9.2.1.2.3  Driver Input Voltage
          4. 9.2.1.2.4  Driver Output Voltage
          5. 9.2.1.2.5  Interconnecting Media
          6. 9.2.1.2.6  PCB Transmission Lines
          7. 9.2.1.2.7  Termination Resistor
          8. 9.2.1.2.8  Driver NC Pins
          9. 9.2.1.2.9  Receiver Supply Voltage
          10. 9.2.1.2.10 Receiver Bypass Capacitance
          11. 9.2.1.2.11 Receiver Input Common-Mode Range
          12. 9.2.1.2.12 Receiver Input Signal
          13. 9.2.1.2.13 Receiver Output Signal
          14. 9.2.1.2.14 Receiver NC Pins
      2. 9.2.2 Application Curve
      3. 9.2.3 Multidrop Communications
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
          1. 9.2.3.2.1 Interconnecting Media
        3. 9.2.3.3 Application Curve
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Microstrip vs. Stripline Topologies
      2. 11.1.2 Dielectric Type and Board Construction
      3. 11.1.3 Recommended Stack Layout
      4. 11.1.4 Separation Between Traces
      5. 11.1.5 Crosstalk and Ground Bounce Minimization
      6. 11.1.6 Decoupling
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Other LVDS Products
    2. 12.2 Third-Party Products Disclaimer
    3. 12.3 Documentation Support
      1. 12.3.1 Related Information
    4. 12.4 Receiving Notification of Documentation Updates
    5. 12.5 Support Resources
    6. 12.6 Trademarks
    7. 12.7 Electrostatic Discharge Caution
    8. 12.8 Glossary
  14. 13Revision History
  15. 14Mechanical, Packaging, and Orderable Information

11.1.3 Recommended Stack Layout

Following the choice of dielectrics and design specifications, you must decide how many levels to use in the stack. To reduce the TTL/CMOS to LVDS crosstalk, it is a good practice to have at least two separate signal planes as shown in Figure 11-3.

SN65LVDS1 SN65LVDS2 SN65LVDT2 Four-Layer PCB Board Figure 11-3 Four-Layer PCB Board
Note:

The separation between layers 2 and 3 should be 127 μm (0.005 in). By keeping the power and ground planes tightly coupled, the increased capacitance acts as a bypass for transients.

One of the most common stack configurations is the six-layer board, as shown in Figure 11-4.

SN65LVDS1 SN65LVDS2 SN65LVDT2 Six-Layer PCB Board Figure 11-4 Six-Layer PCB Board

In this particular configuration, it is possible to isolate each signal layer from the power plane by at least one ground plane. The result is improved signal integrity; however, fabrication is more expensive. Using the 6-layer board is preferable, because it offers the layout designer more flexibility in varying the distance between signal layers and referenced planes, in addition to ensuring reference to a ground plane for signal layers 1 and 6.