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)

8.5.2.4 SMBus Alert Response

The SMBus alert response provides a quick identification for which device issued the interrupt. Without this alert response capability, the processor does not know which device pulled the interrupt line when there are multiple target devices connected.

OPT4001 is designed to respond to the SMBus alert response address, when in the latched window-style comparison mode. The OPT4001 does not respond to the SMBus alert response when in transparent mode.

The response behavior of the device to the SMBus alert response is shown in Figure 8-9. When the interrupt line to the processor is pulled to active, the controller can broadcast the alert response target address. Following this alert response, any target devices that generated an alert identify themselves by acknowledging the alert response and sending respective I2C address on the bus. The alert response can activate several different target devices simultaneously. If more than one target attempts to respond, bus arbitration rules apply. The device with the lowest address wins the arbitration. If the OPT4001 loses the arbitration, the device does not acknowledge the I2C transaction and the INT pin remains in an active state, prompting the I2C controller processor to issue a subsequent SMBus alert response. When the OPT4001 wins the arbitration, the device acknowledges the transaction and sets the INT pin to inactive. The controller can issue that same command again, as many times as necessary to clear the INT pin. See Section 8.4.2 for additional details of how the flags and INT pin are controlled. The controller can obtain information about the source of the OPT4001 interrupt from the address broadcast in the above process. The FLAG_H value is sent as the final LSB of the address to provide the controller additional information about the cause of the OPT4001 interrupt. If the controller requires additional information, the result register or the configuration register can be queried. The FLAG_H and FLAG_L fields are not cleared upon an SMBus alert response.

OPT4001 Timing Diagram for SMBus Alert Response
A. FH is the FLAG_H register
B. A1 and A0 are determined by the ADDR pin (only on SOT-5X3 version)
Figure 8-9 Timing Diagram for SMBus Alert Response