SLLSFN5A June   2023  – February 2024 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 Interface Timing - Non-Daisy Chain
      9. 7.3.9  SPI Interface Timing - Daisy Chain
      10. 7.3.10 SPI Interface 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 Design Requirements
        1. 8.2.3.1 Detailed Design Procedure
          1. 8.2.3.1.1 Current Limit
          2. 8.2.3.1.2 Voltage Thresholds
          3. 8.2.3.1.3 Wire-Break Detection
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Revision History
  14. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Tape and Reel Information

Package Options

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

7.3.9 SPI Interface Timing - Daisy Chain

Figure 7-6 shows an example of two ISO1228 devices in a daisy chain. Up to 8 devices can be daisy chained with ISO1228. Figure 7-7 shows the timing diagram for the SPI interface in daisy chain mode for this two device configuration. The bit W/Rn[x] (1/0) determines Write or Read operation. Ab[x] is a 7-bit register for read or write. Wb[x] is the 8-bit write data for Write operation and is ignored for Read operation. Rb[x] is the 8-bit read data from the register addressed by Ab[x] during Read operation, and should be ignored for Write operation. O8[x]-O1[x] is the state of the 8-digital inputs, IN8-IN1 and is always output on SDO in the address phase.

The Addresses and Data of the the device whose SDO connects to the controller (Device 2 in this example) are shifted in and out first, and those of the device whose SDI is connected to the controller (Device 1 in this example) are shifted in and out last.

If SDI is continously held at Low (0), the devices in the daisy chain will treat this as a Read operation from Address 0. Address 0 holds the state on IN8-IN1 (see SPI Register Map), so in this special case of read operation the SDO output will be IN8-IN1 in both Address and Read Phases. For applications that are only interested in the state of the digital inputs, and do not want to access other registers for Read/Write, this option may result in a simpler implementation.

GUID-20210921-SS0I-22HT-NQGC-KMKWHRBW1FV6-low.svg Figure 7-4 SPI Daisy Chain Block Diagram.
GUID-20210921-SS0I-CHBD-NSPK-THNRPLNP35XX-low.svg Figure 7-5 SPI Timing Daisy Chain .