ZHCS823H March   2012  – March 2019 SN65HVD72 , SN65HVD75 , SN65HVD78

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      典型应用图
  4. 4 修订历史记录
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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
    6. 7.6  Power Dissipation
    7. 7.7  Switching Characteristics: 250 kbps Device (SN65HVD72) Bit Time ≥ 4 µs
    8. 7.8  Switching Characteristics: 20 Mbps Device (SN65HVD75) Bit Time ≥50 ns
    9. 7.9  Switching Characteristics: 50 Mbps Device (SN65HVD78) Bit Time ≥20 ns
    10. 7.10 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
        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
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 External Transient Protection
        2. 10.2.2.2 Isolated Bus Node Design
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13器件和文档支持
    1. 13.1 器件支持
      1. 13.1.1 第三方产品免责声明
    2. 13.2 文档支持
      1. 13.2.1 相关文档
    3. 13.3 相关链接
    4. 13.4 社区资源
    5. 13.5 商标
    6. 13.6 静电放电警告
    7. 13.7 术语表
  14. 14机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

10.2.1.3 Bus Loading

The RS-485 standard specifies that a compliant driver must be able to drive 32 unit loads (UL), where 1 unit load represents a receiver input current of 1 mA at 12 V, or a load impedance of approximately 12 kΩ. Because the SN65HVD72 and SN65HVD75 have a receiver input current of 150 µA at 12 V, they are 3/20 UL transceivers, and no more than 213 transceivers should be connected to the bus. Similarly, the SN65HVD78 has a receiver input current of 333 µA at 12 V and is a 1/3 UL transceiver, meaning no more than 96 transceivers should be connected to the bus.