SNLS622A July   2018  – December 2018 DSLVDS1001

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Functional Diagram
    2.     Typical Application
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. Parameter Measurement Information
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 DSLVDS1001 Driver Functionality
      2. 8.3.2 Driver Output Voltage and Power-On Reset
      3. 8.3.3 Driver Offset
    4. 8.4 Device Functional Modes
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Point-to-Point Communications
    3. 9.3 Design Requirements
    4. 9.4 Detailed Design Procedure
      1. 9.4.1 Driver Supply Voltage
      2. 9.4.2 Driver Bypass Capacitance
      3. 9.4.3 Driver Input Voltage
      4. 9.4.4 Driver Output Voltage
      5. 9.4.5 Interconnecting Media
      6. 9.4.6 PCB Transmission Lines
      7. 9.4.7 Termination Resistor
    5. 9.5 Application Curve
  10. 10Power Supply Recommendations
    1. 10.1 Power Supply Considerations
  11. 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
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

PCB Transmission Lines

As per the LVDS Owner's Manual Design Guide, 4th Edition (SNLA187), Figure 13 depicts several transmission line structures commonly used in printed-circuit boards (PCBs). Each structure has a signal line and a return path with a uniform cross-section along its length. A microstrip is a signal trace on the top (or bottom) layer, separated by a dielectric layer from its return path in a ground or power plane. A stripline is a signal trace in the inner layer, with a dielectric layer in between a ground plane above and below the signal trace. The dimensions of the structure and the dielectric material properties determine the characteristic impedance of the transmission line (also called controlled-impedance transmission line).

When two signal lines are placed close by, they form a pair of coupled transmission lines. Figure 13 shows examples of edge-coupled microstrip lines, and edge-coupled or broad-side-coupled striplines. When excited by differential signals, the coupled transmission line is referred to as a differential pair. The characteristic impedance of each line is called odd-mode impedance. The sum of the odd-mode impedances of each line is the differential impedance of the differential pair. In addition to the trace dimensions and dielectric material properties, the spacing between the two traces determines the mutual coupling and impacts the differential impedance. When the two lines are immediately adjacent (like when S is less than 2W, for example), the differential pair is called a tightly-coupled differential pair. To maintain constant differential impedance along the length, it is important to keep the trace width and spacing uniform along the length, as well as maintain good symmetry between the two lines.

DSLVDS1001 citl_slls373.gifFigure 13. Controlled-Impedance Transmission Lines