SLLSEY7F June   2017  – April 2020

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.          Application Diagram
      2.      ISO121x Devices Reduce Board Temperatures vs Traditional Solutions
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
    2.     Pin Functions
  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—DC Specification
    10. 6.10 Switching Characteristics—AC Specification
    11. 6.11 Insulation Characteristics Curves
    12. 6.12 Typical Characteristics
  7. Parameter Measurement Information
    1. 7.1 Test Circuits
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Sinking Inputs
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Setting Current Limit and Voltage Thresholds
          2. 9.2.1.2.2 Thermal Considerations
          3. 9.2.1.2.3 Designing for 48-V Systems
          4. 9.2.1.2.4 Designing for Input Voltages Greater Than 60 V
          5. 9.2.1.2.5 Surge, ESD, and EFT Tests
          6. 9.2.1.2.6 Multiplexing the Interface to the Host Controller
          7. 9.2.1.2.7 Status LEDs
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Sourcing Inputs
      3. 9.2.3 Sourcing and Sinking Inputs (Bidirectional Inputs)
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Related Links
    4. 12.4 Receiving Notification of Documentation Updates
    5. 12.5 Community Resource
    6. 12.6 Trademarks
    7. 12.7 Electrostatic Discharge Caution
    8. 12.8 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Multiplexing the Interface to the Host Controller

The ISO121x devices provide an output-enable pin on the controller side (EN). Setting the EN pin to 0 causes the output buffers to be in the high-impedance state. This feature can be used to multiplex the outputs of multiple ISO121x devices on the same host-controller input, reducing the number of pins on the host controller.

In the example shown in Figure 25, two sets of 8-channel inputs are multiplexed, reducing the number of input pins required on the controller from 16 to 10. Similarly, if four sets of 8-channel inputs are multiplexed, the number of pins on the controller is reduced from 32 to 12.

ISO1211 ISO1212 iso121x-using-the-output-enable-option-to-multiplex-interface-to-host-controller.gifFigure 25. Using the Output Enable Option to Multiplex the Interface to the Host Controller