SLLSE49E September   2010  – October 2024 SN65HVD1780-Q1 , SN65HVD1781-Q1 , SN65HVD1782-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings—AEC
    3. 5.3  ESD Ratings—IEC
    4. 5.4  Recommended Operating Conditions
    5. 5.5  Thermal Information
    6. 5.6  Electrical Characteristics
    7. 5.7  Power Dissipation Ratings
    8. 5.8  Switching Characteristics
    9. 5.9  Package Dissipation Ratings
    10. 5.10 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Bus Fault Conditions
      2. 7.3.2 Receiver Failsafe
      3. 7.3.3 Hot-Plugging
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Data Rate and Bus Length
        2. 8.2.1.2 Bus Loading
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Stub Length
        2. 8.2.2.2 Receiver Failsafe
      3. 8.2.3 Application Curve
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.4.1 Layout Guidelines

On-chip IEC-ESD protection is good for laboratory and portable equipment but often insufficient for EFT and surge transients occurring in industrial environments. Therefore robust and reliable bus node design requires the use of external transient protection devices.

Because ESD and EFT transients have a wide frequency bandwidth from approximately 3MHz to 3GHz, high-frequency layout techniques must be applied during PCB design.

  1. Place the protection circuitry close to the bus connector to prevent noise transients from entering the board.
  2. Use VCC and ground planes to provide low-inductance. High-frequency currents follow the path of least inductance and not the path of least impedance.
  3. Design the protection components into the direction of the signal path. Do not force the transient currents to divert from the signal path to reach the protection device.
  4. Apply 100nF to 220nF bypass capacitors as close as possible to the VCC pins of the transceiver, UART, or controller ICs on the board.
  5. Use at least two vias for VCC and ground connections of bypass capacitors and protection devices to minimize effective via inductance.
  6. Use 1kΩ to 10kΩ pullup and pulldown resistors for enable lines to limit noise currents in these lines during transient events.
  7. While pure TVS protection is sufficient for surge transients up to 1kV, higher transients require metal-oxide varistors (MOVs) which reduce the transients to a few hundred volts of clamping voltage, and transient blocking units (TBUs) that limit transient current to less than 1mA.