SLLSFN5B June   2023  – September 2025 ISO1228

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
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Power Ratings
    6. 5.6  Insulation Specifications
    7. 5.7  Safety-Related Certifications
    8. 5.8  Safety Limiting Values
    9. 5.9  Electrical Characteristics—DC Specification
    10. 5.10 Switching Characteristics—AC Specification
    11. 5.11 Typical Characteristics
  7. 6 Parameter Measurement Information
    1. 6.1 Test Circuits
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Surge Protection
      2. 7.3.2  Field Side LED Indication
      3. 7.3.3  Serial and Parallel Output option
      4. 7.3.4  Cyclic Redundancy Check (CRC)
      5. 7.3.5  FAULT Indication
      6. 7.3.6  Digital Low Pass Filter
      7. 7.3.7  SPI Register Map
      8. 7.3.8  SPI Timing - Non-Daisy Chain
      9. 7.3.9  SPI Timing - Daisy Chain
      10. 7.3.10 SPI Timing - Burst Mode
    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 Sinking Type Digital Inputs
      2. 8.2.2 Sourcing Type Digital Inputs
      3. 8.2.3 Sink/Source Type Digital Inputs
      4. 8.2.4 Design Requirements
        1. 8.2.4.1 Detailed Design Procedure
          1. 8.2.4.1.1 Current Limit
          2. 8.2.4.1.2 Voltage Thresholds
          3. 8.2.4.1.3 Wire-Break Detection
    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 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.4.1 Layout Guidelines

The board layout for ISO1228 can be completed in two layers. On the field side, place RTHR, CIN, RPAR, RILIM, CFIL, RSURGE, and CSURGE on the top layer. Use the bottom layer as the field ground (FGND) plane. TI recommends using RPAR and CIN in 0603 footprints for a compact layout, although larger sizes (0805) can also be used. The CIN capacitor is a 50V capacitor and is available in the 0603 footprint. Keep CIN as close to the ISO1228 device as possible. TI recommends using RTHR, RSURGE, RILIM in MELF 0204 footprint surge-proof resistors and 0805 footprint 50V capacitors for CSURGE and CFIL. The placement of the RTHR resistor is flexible, although the resistor pin connected to external high voltage must not be placed within 4mm of the ISO1228 device pins or the CIN and RPAR pins to avoid flashover during EMC tests. The placement of LEDs is flexible to display the channel status on the field side.

Only a decoupling capacitor is required on side 1. Place this capacitor on the top-layer, with the bottom layer for GND1.

Layout Example shows the example layout.