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

Application Curves

To validate that the design example now measures correctly, create a sequential number of different light intensities with the fluorescent light by using neutral density filters to attenuate the light. Different light intensities can also be created by changing the distance between the light source, and the measurement devices. However, these two methods for changing the light level have minor accuracy tradeoffs that are beyond the scope of this discussion. Measure each intensity with both the lux meter and the OPT3004 under the window, and compensate using Equation 5. The results are displayed in Figure 9-5, and show that the application accurately reports results very similar to the lux meter.

To validate that the design measures a variety of light sources correctly, despite the large ratio of infrared transmission to visible light transmission of the window, measure the application with a halogen bulb and an incandescent bulb. Use the physical location and light attenuation procedures that were used for the fluorescent light. The results are shown in Figure 9-6.

The addition of the dark window changes the results as seen by comparing the results of the same measurement with a window (Figure 9-6) and without a window (Figure 7-4). Even after the expected change, the performance is still good. All data are both within 15% of the correct answer, and within 15% of the other bulb measurements.

Results can vary at different angles of light because the OPT3004 does not match the lux meter at all angles of light.

If the measurement variation between the light sources is not acceptable, choose a different window that has a closer ratio of visible light transmission to infrared light transmission.

OPT3004 Uncompensated and Compensated Output of the OPT3004 Under a Dark Window Illuminated by Fluorescent Light SourceFigure 9-5 Uncompensated and Compensated Output of the OPT3004 Under a Dark Window Illuminated by Fluorescent Light Source
OPT3004 Compensated Output of the OPT3004 Under a Dark Window Illuminated by Fluorescent, Halogen, and Incandescent Light SourcesFigure 9-6 Compensated Output of the OPT3004 Under a Dark Window Illuminated by Fluorescent, Halogen, and Incandescent Light Sources