SBOSA84 December   2022 OPT4048

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 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
  8. 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 CIE
      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
        3. 8.3.3.3 Threshold Detection
      4. 8.3.4 Device Functional Modes
        1. 8.3.4.1 Modes of Operation
        2. 8.3.4.2 Interrupt Modes of Operation
        3. 8.3.4.3 Light Range Selection
        4. 8.3.4.4 Selecting Conversion Time
        5. 8.3.4.5 Light and Color Measurement
        6. 8.3.4.6 Light Resolution
        7. 8.3.4.7 Programming
          1. 8.3.4.7.1 I2C Bus Overview
            1. 8.3.4.7.1.1 Serial Bus Address
            2. 8.3.4.7.1.2 Serial Interface
          2. 8.3.4.7.2 Writing and Reading
            1. 8.3.4.7.2.1 High-Speed I2C Mode
            2. 8.3.4.7.2.2 Burst Read Mode
            3. 8.3.4.7.2.3 General-Call Reset Command
            4. 8.3.4.7.2.4 SMBus Alert Response
    4. 8.4 Register Maps
      1. 8.4.1 ALL Register Map
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Electrical Interface
      2. 9.2.2 Design Requirements
        1. 9.2.2.1 Optical Interface
      3. 9.2.3 Detailed Design Procedure
        1. 9.2.3.1 Optomechanical Design
      4. 9.2.4 Application Curves
    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
      3. 9.5.3 Soldering and Handling Recommendations
  10. 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
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.4.3 Light Range Selection

The OPT4048 has an automatic full-scale-range setting mode that eliminates the need for a user to predict and set the best range for the device. This mode is entered when register RANGE is set to 0xC. The device determines the appropriate full-scale range to take the measurement based on a combination of current lighting conditions and the previous measurement.

If a measurement is towards the low side of full-scale, then the full-scale range is decreased by one or two settings for the next measurement. If a measurement is towards the upper side of full-scale, the full-scale range is increased by one setting for the next measurement.

If the measurement exceeds the full-scale range, resulting from a fast increasing optical transient event, then the current measurement is aborted. This invalid measurement is not reported. If the scale is not at the maximum, then the device increases the scale by one step and a new measurement is retaken with that scale. Therefore, during a fast increasing optical transient in this mode, a measurement can possibly take longer to complete and report than indicated by the configuration register CONVERSION_TIME.

The logic that determines the appropriate range settings for each channel is independent of each other, which verifies a support of a wide range of colors represented with the best accuracy.

TI highly recommends to use this feature, since the device selects the best range setting based on lighting condition. However, there is an option to manually set the range. Setting the range manually turns off the automatic full-scale selection logic and the device operates for a particular range setting.

Table 8-3 Range Selection Table
RANGE register setting Typical Full-scale Light level
0 2254 lux
1 4509 lux
2 9018 lux
3 18036 lux
4 36071 lux
5 72142 lux
6 144284 lux
12 Determined by automatic full-scale range logic