SLLSEY7F June   2017  – April 2020 ISO1211 , ISO1212

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.          Application Diagram
      2.      ISO121x Devices Reduce Board Temperatures vs Traditional Solutions
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
    2.     Pin Functions
  6. 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. 7 Parameter Measurement Information
    1. 7.1 Test Circuits
  8. 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. 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

9.2.1 Sinking Inputs

Figure 16 shows the design for a typical multichannel, isolated digital-input module with sinking inputs. Push-button switches, proximity sensors, and other field inputs connect to the host controller through an isolated interface. The design is easily scalable from a few channels, such as 4 or 8, to many channels, such as 256 or more. The RSENSE resistor limits the current drawn from the input pins. The RTHR resistor is used to adjust the voltage thresholds and limit the peak current during surge events. The CIN capacitor is used to filter noise on the input pins. For more information on selecting RSENSE, RTHR, and CIN, see the Detailed Design Procedure section.

The ISO121x devices derive field-side power from the input pins which eliminates the requirement for a field-side, 24-V input power supply to the module. Similarly, an isolated dc-dc converter creating a field-side power supply from the controller side back plane supply is also eliminated which improves flexibility of system design and reduces system cost.

For systems requiring channel-to-channel isolation on the field side, use the ISO1211 device as shown in Figure 17.

ISO1211 ISO1212 iso121x-typical-high-density-multi-channel-digital-input-module-with-iso1212.gifFigure 16. Typical Application Schematic With Sinking Inputs
ISO1211 ISO1212 iso121x-single-channel-or-channel-to-channel-isolated-designs-with-iso1211.gifFigure 17. Single-Channel or Channel-to-Channel Isolated Designs With ISO1211