JAJSH84G May   2014  – October 2019 SN65HVD70 , SN65HVD71 , SN65HVD73 , SN65HVD74 , SN65HVD76 , SN65HVD77

PRODUCTION DATA.  

  1. 特長
  2. アプリケーション
  3. 概要
    1.     ブロック図
  4. 改訂履歴
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     Pin Functions — SOIC-8 and MSOP-8
    2.     Pin Functions — MSOP–10
    3.     Pin Functions — SOIC-14
  7. Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information — D Packages
    5. 7.5  Thermal Information — DGS and DGK Packages
    6. 7.6  Power Dissipation
    7. 7.7  Electrical Characteristics
    8. 7.8  Switching Characteristics — 400 kbps
    9. 7.9  Switching Characteristics — 20 Mbps
    10. 7.10 Switching Characteristics — 50 Mbps
    11. 7.11 Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
    4. 9.4 Device Functional Modes
      1. 9.4.1 Equivalent Circuits
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1.      Master Enable Control
      2.      Slave Enable Control
      3. 10.2.1 Design Parameters
        1. 10.2.1.1 Data Rate and Bus Length
        2. 10.2.1.2 Stub Length
        3. 10.2.1.3 Bus Loading
        4. 10.2.1.4 Receiver Failsafe
        5. 10.2.1.5 Transient Protection
      4. 10.2.2 Detailed Design Procedure
      5. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 デバイス・サポート
      1. 13.1.1 デベロッパー・ネットワークの製品に関する免責事項
    2. 13.2 関連リンク
    3. 13.3 ドキュメントの更新通知を受け取る方法
    4. 13.4 コミュニティ・リソース
    5. 13.5 商標
    6. 13.6 静電気放電に関する注意事項
    7. 13.7 Glossary
  14. 14メカニカル、パッケージ、および注文情報

Transient Protection

The bus pins of the SN65HVD7x full-duplex transceiver family include on-chip ESD protection against ±30-kV HBM and ±12-kV IEC 61000-4-2 contact discharge. The International Electrotechnical Commission (IEC) ESD test is far more severe than the HBM ESD test. The 50% higher charge capacitance, C(S), and 78% lower discharge resistance, R(D), of the IEC model produce significantly higher discharge currents than the HBM model.

As stated in the IEC 61000-4-2 standard, contact discharge is the preferred transient protection test method. Although IEC air-gap testing is less repeatable than contact testing, air discharge protection levels are inferred from contact discharge test results.

SN65HVD70 SN65HVD71 SN65HVD73 SN65HVD74 SN65HVD76 SN65HVD77 HBM_app_sllsei9.gifFigure 34. HBM and IEC ESD Models and Currents in Comparison (HBM Values in Parenthesis)

The on-chip implementation of IEC ESD protection significantly increases the robustness of equipment. Common discharge events occur because of human contact with connectors and cables. Designers may choose to implement protection against longer duration transients, typically referred to as surge transients.

EFTs are generally caused by relay-contact bounce or the interruption of inductive loads. Surge transients often result from lightning strikes (direct strike or an indirect strike which induce voltages and currents), or the switching of power systems, including load changes and short circuit switching. These transients are often encountered in industrial environments, such as factory automation and power-grid systems.

Figure 35 compares the pulse-power of the EFT and surge transients with the power caused by an IEC ESD transient. The left hand diagram shows the relative pulse-power for a 0.5kV surge transient and 4-kV EFT transient, both of which dwarf the 10-kV ESD transient visible in the lower-left corner. 500-V surge transients are representative of events that may occur in factory environments in industrial and process automations.

The right hand diagram shows the pulse-power of a 6-kV surge transient, relative to the same 0.5-kV surge transient. 6-kV surge transients are most likely to occur in power generation and power-grid systems.

SN65HVD70 SN65HVD71 SN65HVD73 SN65HVD74 SN65HVD76 SN65HVD77 power_comp_sllsei9.gifFigure 35. Power Comparison of ESD, EFT, and Surge Transients

In the case of surge transients, high-energy content is characterized by long pulse duration and slow decaying pulse power. The electrical energy of a transient that is dumped into the internal protection cells of a transceiver is converted into thermal energy, which heats and destroys the protection cells, thus destroying the transceiver. Figure 36 shows the large differences in transient energies for single ESD, EFT, surge transients, and an EFT pulse train that is commonly applied during compliance testing.

SN65HVD70 SN65HVD71 SN65HVD73 SN65HVD74 SN65HVD76 SN65HVD77 comp_trans_sllsei9.gifFigure 36. Comparison of Transient Energies