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

Package Options

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

8.5.1 I2C Bus Overview

The OPT4001 offers compatibility with both I2C and SMBus interfaces. The I2C and SMBus protocols are essentially compatible with one another. The I2C interface is used throughout this document as the primary example with the SMBus protocol specified only when a difference between the two protocols is discussed.

The device is connected to the bus with two pins: an SCL clock input pin and an SDA open-drain bidirectional data pin. The bus must have a controller device that generates the serial clock (SCL), controls the bus access, and generates start and stop conditions. To address a specific device, the controller initiates a start condition by pulling the data signal line (SDA) from a high logic level to a low logic level while SCL is high. All targets on the bus shift in the target address byte on the SCL rising edge, with the last bit indicating whether a read or write operation is intended. During the ninth clock pulse, the target being addressed responds to the controller by generating an acknowledge bit by pulling SDA low.

Data transfer is then initiated and eight bits of data are sent, followed by an acknowledge bit. During data transfer, SDA must remain stable while SCL is high. Any change in SDA while SCL is high is interpreted as a start or stop condition. When all data are transferred, the controller generates a stop condition, indicated by pulling SDA from low to high while SCL is high. The device includes a 28-ms timeout on the I2C interface to prevent locking up the bus. If the SCL line is held low for this duration of time, the bus state machine is reset.