SBOS929A December   2018  – December 2021 OPT3004

PRODMIX  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Revision History
  6. Description (continued)
  7. Pin Configuration and Functions
  8. 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 Timing Requirements
    7. 7.7 Typical Characteristics
  9. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Human Eye Matching
      2. 8.3.2 Automatic Full-Scale Range Setting
      3. 8.3.3 Interrupt Operation, INT Pin, and Interrupt Reporting Mechanisms
      4. 8.3.4 I2C Bus Overview
        1. 8.3.4.1 Serial Bus Address
        2. 8.3.4.2 Serial Interface
    4. 8.4 Device Functional Modes
      1. 8.4.1 Automatic Full-Scale Setting Mode
      2. 8.4.2 Interrupt Reporting Mechanism Modes
        1. 8.4.2.1 Latched Window-Style Comparison Mode
        2. 8.4.2.2 Transparent Hysteresis-Style Comparison Mode
        3. 8.4.2.3 End-of-Conversion Mode
        4. 8.4.2.4 End-of-Conversion and Transparent Hysteresis-Style Comparison Mode
    5. 8.5 Programming
      1. 8.5.1 Writing and Reading
        1. 8.5.1.1 High-Speed I2C Mode
        2. 8.5.1.2 General-Call Reset Command
        3. 8.5.1.3 SMBus Alert Response
    6. 8.6 Register Maps
      1. 8.6.1 Internal Registers
      2. 8.6.2 Register Descriptions
        1. 8.6.2.1 Result Register (offset = 00h)
        2. 8.6.2.2 Configuration Register (offset = 01h) [reset = C810h]
        3. 8.6.2.3 Low-Limit Register (offset = 02h) [reset = C0000h]
        4. 8.6.2.4 High-Limit Register (offset = 03h) [reset = BFFFh]
        5. 8.6.2.5 Manufacturer ID Register (offset = 7Eh) [reset = 5449h]
        6. 8.6.2.6 Device ID Register (offset = 7Fh) [reset = 3001h]
  10. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Electrical Interface
      2. 9.1.2 Optical Interface
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Optomechanical Design
        2. 9.2.2.2 Dark Window Selection and Compensation
      3. 9.2.3 Application Curves
    3. 9.3 Do's and Don'ts
  11. 10Power-Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Soldering and Handling Recommendations
    4. 11.4 DNP (S-PDSO-N6) Mechanical Drawings
    5. 11.5 DTS (SOT-5X3) Mechanical Drawings
  13. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Mechanical, Packaging, and Orderable Information
    1. 13.1 Tape and Reel Information

Electrical Interface

The electrical interface is quite simple, as illustrated in Figure 9-1. Connect the OPT3004 I2C SDA and SCL pins to the same pins of an applications processor, microcontroller, or other digital processor. If that digital processor requires an interrupt resulting from an event of interest from the OPT3004, then connect the INT pin to either an interrupt or general-purpose I/O pin of the processor. There are multiple uses for this interrupt, including signaling the system to wake up from low-power mode, processing other tasks while waiting for an ambient light event of interest, or alerting the processor that a sample is ready to be read. Connect pullup resistors between a power supply appropriate for digital communication and the SDA and SCL pins (because they have open-drain output structures). If the INT pin is used, connect a pullup resistor to the INT pin. A typical value for these pullup resistors is 10 kΩ. The resistor choice can be optimized in conjunction to the bus capacitance to balance the system speed, power, noise immunity, and other requirements.

The power supply and grounding considerations are discussed in the Power-Supply Recommendations section.

Although spike suppression is integrated in the SDA and SCL pin circuits, use proper layout practices to minimize the amount of coupling into the communication lines. One possible introduction of noise occurs from capacitively coupling signal edges between the two communication lines themselves. Another possible noise introduction comes from other switching noise sources present in the system, especially for long communication lines. In noisy environments, shield communication lines to reduce the possibility of unintended noise coupling into the digital I/O lines that could be incorrectly interpreted.