SLLSF86D May   2018  – August 2026 ISOW1412 , ISOW1432

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  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
    5. 6.5  Power Ratings
    6. 6.6  Insulation Specifications
    7. 6.7  Safety-Related Certifications
    8. 6.8  Safety Limiting Values
    9. 6.9  Electrical Characteristics
    10. 6.10 Supply Current Characteristics at VISOOUT = 3.3 V
    11. 6.11 Supply Current Characteristics at  VISOOUT = 5 V
    12. 6.12 Switching Characteristics at VISOOUT = 3.3 V
    13. 6.13 Switching Characteristics at VISOOUT = 5 V
    14. 6.14 Insulation Characteristics Curves
    15. 6.15 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Power Isolation
    3. 8.3 Signal Isolation
    4. 8.4 RS-485
    5. 8.5 Functional Block Diagram
    6. 8.6 Feature Description
      1. 8.6.1 Power-Up and Power-Down Behavior
      2. 8.6.2 Protection Features
      3. 8.6.3 Failsafe Receiver
      4. 8.6.4 Glitch-Free Power Up and Power Down
    7. 8.7 Device Functional Modes
    8. 8.8 Device I/O Schematics
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Data Rate, Bus Length and Bus Loading
        2. 9.2.2.2 Stub Length
      3. 9.2.3 Insulation Lifetime
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

8.6.3 Failsafe Receiver

The differential receiver of the ISOW14x2 devices has failsafe protection from invalid bus states caused by:

  • Open bus conditions such as a broken cable or a disconnected connector
  • Shorted bus conditions such as insulation breakdown of a cable that shorts the twisted-pair
  • Idle bus conditions that occur when no driver on the bus is actively driving.

The differential input of the RS-485 receiver is 0 in any of these conditions for a terminated transmission line. The receiver outputs a failsafe logic-high state on R pin so that the output of the receiver is determinate. The receiver thresholds are offset in the receiver design so that the indeterminate range does not include a 0V differential. See Receiver functional table for more details.