SLLS261N July   1997  – April 2021 SN55LVDS31 , SN65LVDS31 , SN65LVDS3487 , SN65LVDS9638

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (Continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings (1)
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics: SN55LVDS31
    6. 7.6 Electrical Characteristics: SN65LVDSxxxx
    7. 7.7 Switching Characteristics: SN55LVDS31
    8. 7.8 Switching Characteristics: SN65LVDSxxxx
    9. 7.9 Typical Characteristics
      1. 7.9.1 17
  8. 8 Parameter Measurement Information
    1. 8.1 19
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Driver Disabled Output
      2. 9.3.2 NC Pins
      3. 9.3.3 Unused Enable Pins
      4. 9.3.4 Driver Equivalent Schematics
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Point-to-Point Communications
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Driver Supply Voltage
          2. 10.2.1.2.2 Driver Bypass Capacitance
          3. 10.2.1.2.3 Driver Output Voltage
          4. 10.2.1.2.4 Interconnecting Media
          5. 10.2.1.2.5 PCB Transmission Lines
          6. 10.2.1.2.6 Termination Resistor
          7. 10.2.1.2.7 Driver NC Pins
        3. 10.2.1.3 Application Curve
      2. 10.2.2 Multidrop Communications
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
          1. 10.2.2.2.1 Interconnecting Media
        3. 10.2.2.3 Application Curve
  11. 11Power Supply Recommendations
    1. 11.1 49
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Microstrip vs. Stripline Topologies
      2. 12.1.2 Dielectric Type and Board Construction
      3. 12.1.3 Recommended Stack Layout
      4. 12.1.4 Separation Between Traces
      5. 12.1.5 Crosstalk and Ground Bounce Minimization
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Other LVDS Products
    2. 13.2 Documentation Support
      1. 13.2.1 Related Information
      2. 13.2.2 Receiving Notification of Documentation Updates
      3. 13.2.3 Related Links
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

9.3.4 Driver Equivalent Schematics

The driver input is represented by a CMOS inverter stage with a 7-V Zener diode. The input stage is high-impedance, and includes an internal pulldown to ground. If the driver input is left open, the driver input provides a low-level signal to the rest of the driver circuitry, resulting in a low-level signal at the driver output pins. The Zener diode provides ESD protection. The driver output stage is a differential pair, one half of which is shown in Figure 9-1. Like the input stage, the driver output includes Zener diodes for ESD protection. The schematic shows an output stage that includes a set of current sources (nominally 3.5 mA) that are connected to the output load circuit based upon the input stage signal. To the first order, the SNx5LVDSxx output stage acts a constant-current source.

GUID-555D6387-E6C5-4F54-9C39-26E7F8769D18-low.gifFigure 9-1 Equivalent Input and Output Schematic Diagrams