SLLS562O august   2009  – july 2023 SN65HVD3082E , SN65HVD3085E , SN65HVD3088E , SN75HVD3082E

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information, SN65HVD308xE
    5. 6.5  Thermal Information, SNx5HVD3082E
    6. 6.6  Electrical Characteristics: Driver
    7. 6.7  Electrical Characteristics: Receiver
    8. 6.8  Electrical Characteristics
    9. 6.9  Switching Characteristics: Driver
    10. 6.10 Switching Characteristics
    11. 6.11 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
  10. 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
        4. 9.2.1.4 Receiver Fail-safe
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Power Usage in an RS-485 Transceiver
        2. 9.2.2.2 Low-Power Shutdown Mode
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations for IC Packages
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.1 Application Information

The SNx5HVD308xE devices are half-duplex RS-485 transceivers commonly used for asynchronous data transmissions. The driver and receiver enable pins allow the configuration of different operating modes.

GUID-120D2BA6-D8AC-4372-B9DD-CF77B01FED40-low.gifFigure 9-1 Half-Duplex Transceiver Configurations

Using independent enable lines provides the most flexible control, as it allows the driver and the receiver to be turned on and off individually. While this configuration requires two control lines, it allows selective listening into the bus traffic whether the driver is transmitting data or not.

Combining the enable signals simplify the interface to the controller, by forming a single direction-control signal. In this configuration, the transceiver operates as a driver when the direction-control line is high and as a receiver when the direction-control line is low.

Additionally, only one line is required when connecting the receiver-enable input to ground and controlling only the driver-enable input. In this configuration, a node not only receives the data from the bus, but also the data it sends and can verify that the correct data has been transmitted.