SBOS993A December   2021  – December 2022 OPT4001

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Description (continued)
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Spectral Matching to Human Eye
      2. 8.3.2 Automatic Full-Scale Range Setting
      3. 8.3.3 Output Register CRC and Counter
        1. 8.3.3.1 Output Sample Counter
        2. 8.3.3.2 Output CRC
      4. 8.3.4 Output Register FIFO
      5. 8.3.5 Threshold Detection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Modes of Operation
      2. 8.4.2 Interrupt Modes of Operation
      3. 8.4.3 Light Range Selection
      4. 8.4.4 Selecting Conversion Time
      5. 8.4.5 Light Measurement in Lux
      6. 8.4.6 Light Resolution
    5. 8.5 Programming
      1. 8.5.1 I2C Bus Overview
        1. 8.5.1.1 Serial Bus Address
        2. 8.5.1.2 Serial Interface
      2. 8.5.2 Writing and Reading
        1. 8.5.2.1 High-Speed I2C Mode
        2. 8.5.2.2 Burst Read Mode
        3. 8.5.2.3 General-Call Reset Command
        4. 8.5.2.4 SMBus Alert Response
    6. 8.6 Register Maps
      1. 8.6.1 ALL Register Map
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Electrical Interface
        1. 9.2.1.1 Design Requirements
          1. 9.2.1.1.1 Optical Interface
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Optomechanical Design (PicoStar Variant)
          2. 9.2.1.2.2 Optomechanical Design (SOT-5X3 Variant)
        3. 9.2.1.3 Application Curves (PicoStar Variant)
    3. 9.3 Do's and Don'ts
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
        1. 9.5.2.1 Soldering and Handling Recommendations (SOT-5X3 Variant)
        2. 9.5.2.2 Soldering and Handling Recommendations (PicoStar Variant)
          1. 9.5.2.2.1 Solder Paste
          2. 9.5.2.2.2 Package Placement
          3. 9.5.2.2.3 Reflow Profile
          4. 9.5.2.2.4 Special Flexible Printed-Circuit Board (FPCB) Recommendations
          5. 9.5.2.2.5 Rework Process
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information
    2. 11.2 Package Option Addendum

8.5.2.2 Burst Read Mode

OPT4001 supports I2C burst read mode which helps in minimizing 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 the output registers and FIFO registers which are in continuous locations, are writing the register pointer every 2 bytes, this takes up several clock cycles. With the burst mode enabled, the read pointer address is auto incremented after every register read (2 bytes), eliminating the need write operations to set the pointer for subsequent register reads.

Burst mode can be enabled by setting the register I2C_BURST. When a STOP command is issued the pointer resets to the original register address before the auto-increments.

OPT4001 I2C Operations Figure 8-8 I2C Operations