SLLSF68 September   2019 THVD1505

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Network Application With Polarity Correction (POLCOR)
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 ESD Ratings [IEC]
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Thermal Information
    6. 6.6 Electrical Characteristics
    7. 6.7 Power Dissipation Characteristics
    8. 6.8 Switching Characteristics
    9. 6.9 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Driver
    2. 7.2 Receiver
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Bus Polarity Correction
        1. 8.3.1.1 Passive Polarity Definition Using Fail-Safe Biasing Network
        2. 8.3.1.2 Active Polarity Definition by the Master Node
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Device Configuration
      2. 9.1.2 Bus Design
      3. 9.1.3 Fail-Safe Biasing for Passive Polarity Definition
      4. 9.1.4 Cable Length Versus Data Rate
      5. 9.1.5 Stub Length
      6. 9.1.6 Transient Protection
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Design and Layout Considerations For Transient Protection
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    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

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.1.5 Stub Length

When connecting a node to the bus, the distance between the transceiver inputs and the cable trunk, known as the stub, should be as short as possible. The reason for the short distance is because a stub presents a non-terminated piece of bus line which can introduce reflections if the distance is too long. As a general guideline, the electrical length or round-trip delay of a stub should be less than one-tenth of the rise time of the driver, thus leading to a maximum physical stub length of as shown in Equation 2.

Equation 2. LS ≤ 0.1 × tr × v × c

where

  • tr is the 10/90 rise time of the driver
  • c is the speed of light (3 × 108 m/s or 9.8 × 108 ft/s)
  • v is the signal velocity of the cable (v = 78%) or trace (v = 45%) as a factor of c

Based on Equation 2, with a minimum rise time of 400 ns, Equation 3 shows the maximum cable-stub length of the THVD1505.

Equation 3. LS ≤ 0.1 × 400 × 10-9 × 3 108 × 0.78 = 9.4 m (or 30.6 ft)
THVD1505 stub_length_llsed6.gifFigure 24. Stub Length