SBOSA93C May   2023  – June 2024 OPT4001-Q1

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 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Timing Diagram
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Spectral Matching to Human Eye
      2. 6.3.2 Automatic Full-Scale Range Setting
      3. 6.3.3 Error Correction Code (ECC) Features
        1. 6.3.3.1 Output Sample Counter
        2. 6.3.3.2 Output CRC
      4. 6.3.4 Output Register FIFO
      5. 6.3.5 Threshold Detection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Modes of Operation
      2. 6.4.2 Interrupt Modes of Operation
      3. 6.4.3 Light Range Selection
      4. 6.4.4 Selecting Conversion Time
      5. 6.4.5 Light Measurement in Lux
      6. 6.4.6 Threshold Detection Calculations
      7. 6.4.7 Light Resolution
    5. 6.5 Programming
      1. 6.5.1 I2C Bus Overview
        1. 6.5.1.1 Serial Bus Address
        2. 6.5.1.2 Serial Interface
      2. 6.5.2 Writing and Reading
        1. 6.5.2.1 High-Speed I2C Mode
        2. 6.5.2.2 Burst Read Mode
        3. 6.5.2.3 General-Call Reset Command
        4. 6.5.2.4 SMBus Alert Response (USON Variant)
  8. 7 Register Maps
    1. 7.1 Register Descriptions
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Electrical Interface
        1. 8.2.1.1 Design Requirements
          1. 8.2.1.1.1 Optical Interface
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Optomechanical Design (PicoStar Variant)
          2. 8.2.1.2.2 Optomechanical Design (USON Variant)
        3. 8.2.1.3 Application Curves (PicoStar Variant)
        4. 8.2.1.4 Application Curves (USON Variant)
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Soldering and Handling Recommendations (PicoStar Variant)
          1. 8.5.1.1.1 Solder Paste
          2. 8.5.1.1.2 Package Placement
          3. 8.5.1.1.3 Reflow Profile
          4. 8.5.1.1.4 Special Flexible Printed-Circuit Board (FPCB) Recommendations
          5. 8.5.1.1.5 Rework Process
        2. 8.5.1.2 Soldering and Handling Recommendations (USON Variant)
      2. 8.5.2 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

6.5.2.2 Burst Read Mode

The OPT4001-Q1 supports I2C burst read mode, which helps minimize the number of transactions on the bus for efficient data transfer from the device to the controller.

Before considering the burst mode, a regular I2C read transaction involves an I2C write operation to the device read pointer, followed by the actual I2C read operation. If regular I2C read transactions are performed when reading from the output registers and FIFO registers, which are in continuous locations, then the register pointer is written every two bytes and this process takes up several clock cycles. With the burst mode enabled, the read pointer address is auto incremented after every register read (two bytes), eliminating the need to write operations to set the pointer for subsequent register reads.

Set the I2C_BURST register to enable burst mode. When a stop command is issued, the pointer resets to the original register address before the auto-increments. Figure 6-8 shows a diagram of the I2C write, single read, and burst mode read operation.

OPT4001-Q1 I2C Operations Figure 6-8 I2C Operations