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

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|8
  • DBV|5
Thermal pad, mechanical data (Package|Pins)
Orderable Information
9.2.1.2.7 Termination Resistor

As shown earlier, an LVDS communication channel employs a current source driving a transmission line which is terminated with a resistive load. This load serves to convert the transmitted current into a voltage at the receiver input. To ensure incident wave switching (which is necessary to operate the channel at the highest signaling rate), the termination resistance should be matched to the characteristic impedance of the transmission line. The designer should ensure that the termination resistance is within 10% of the nominal media characteristic impedance. If the transmission line is targeted for 100-Ω impedance, the termination resistance should be between 90 Ω and 110 Ω.

The line termination resistance should be located as close as possible to the receiver, thereby minimizing the stub length from the resistor to the receiver. The limiting case would be to incorporate the termination resistor into the receiver, which is exactly what is offered with the SN65LVDT2. The SN65LVDT2 provides all the functionality and performance of the SN65LVDS2 receiver, with the added feature of an integrated termination load.

While we talk in this section about point-to-point communications, a word of caution is useful when a multidrop topology is used. In such topologies, line termination resistors are to be located only at the end(s) of the transmission line. In such an environment, SN65LVDS2 receivers could be used for loads branching off the main bus, with an SN65LVDT2 used only at the bus end.