JAJSPU9M september   2005  – february 2023 SN65HVD30 , SN65HVD31 , SN65HVD32 , SN65HVD33 , SN65HVD34 , SN65HVD35

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Device Comparison
    1.     6
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics: Driver
    6. 7.6  Electrical Characteristics: Receiver
    7. 7.7  Device Power Dissipation – PD
    8. 7.8  Supply Current Characteristics
    9. 7.9  Switching Characteristics: Driver
    10. 7.10 Switching Characteristics: Receiver
    11. 7.11 Dissipation Ratings
    12. 7.12 Typical Characteristics
      1.      Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Low-Power Standby Mode
      2. 8.3.2 Driver Output Current Limiting
      3. 8.3.3 Hot-Plugging
      4. 8.3.4 Receiver Failsafe
      5. 8.3.5 Safe Operation With Bus Contention
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Data Rate and Bus Length
        2. 9.2.1.2 Stub Length
        3. 9.2.1.3 Bus Loading
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 ドキュメントの更新通知を受け取る方法
    2. 10.2 サポート・リソース
    3. 10.3 Trademarks
    4. 10.4 静電気放電に関する注意事項
    5. 10.5 用語集
  11. 11Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.2.1.2 Stub Length

When connecting a node to the bus, the distance between the transceiver inputs and the cable trunk, known as the stub, must be as short as possible. Stubs present a nonterminated piece of bus line that can introduce reflections as the length of the stub increases. As a general guideline, the electrical length, or round-trip delay, of a stub must be less than one-tenth of the rise time of the driver; thus giving a maximum physical stub length as shown in Equation 1.

Equation 1. Lstub ≤ 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)
  • v is the signal velocity of the cable or trace as a factor of c

Per Equation 1, Table 9-1 shows the maximum cable-stub lengths for the minimum driver output rise times of the SN65HVD3x full-duplex family of transceivers for a signal velocity of 78%.

Table 9-1 Maximum Stub Length
DEVICEMINIMUM DRIVER OUTPUT RISE TIME (ns)MAXIMUM STUB LENGTH
(m)(ft)
SN65HVD3040.10.3
SN65HVD31250.61.9
SN65HVD321202.89.2
SN65HVD3340.10.3
SN65HVD34250.61.9
SN65HVD351202.89.2