SLLSE11H March   2012  – March 2019 SN65HVD72 , SN65HVD75 , SN65HVD78

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Diagram
  4. 4 Revision History
  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. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Related Links
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

10.2.2.1 External Transient Protection

To protect bus nodes against high-energy transients, the implementation of external transient protection devices is necessary. Figure 26 suggests two circuits that provide protection against light and heavy surge transients, in addition to ESD and EFT transients. Table 4 presents the associated bill of materials.

Table 4. Bill of Materials

DEVICE FUNCTION ORDER NUMBER MANUFACTURER
XCVR 3.3-V, 250-kbps RS-485 Transceiver SN65HVD72D TI
R1, R2 10-Ω, Pulse-Proof Thick-Film Resistor CRCW060310RJNEAHP Vishay
TVS Bidirectional 400-W Transient Suppressor CDSOT23-SM712 Bourns
TBU1, TBU2 Bidirectional Surge Suppressor TBU-CA-065-200-WH Bourns
MOV1, MOV2 200-mA Transient Blocking Unit, 200-V, Metal-Oxide Varistor MOV-10D201K Bourns
SN65HVD72 SN65HVD75 SN65HVD78 prot_app_llse11.gifFigure 26. Transient Protections Against ESD, EFT, and Surge Transients

The left-hand circuit provides surge protection of ≥500-V surge transients, while the right-hand circuit can withstand surge transients of up to 5 kV.