SBOSA93C May   2023  – June 2024 OPT4001-Q1

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
  6. Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Timing Diagram
    8. 5.8 Typical Characteristics
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Spectral Matching to Human Eye
      2. 6.3.2 Automatic Full-Scale Range Setting
      3. 6.3.3 Error Correction Code (ECC) Features
        1. 6.3.3.1 Output Sample Counter
        2. 6.3.3.2 Output CRC
      4. 6.3.4 Output Register FIFO
      5. 6.3.5 Threshold Detection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Modes of Operation
      2. 6.4.2 Interrupt Modes of Operation
      3. 6.4.3 Light Range Selection
      4. 6.4.4 Selecting Conversion Time
      5. 6.4.5 Light Measurement in Lux
      6. 6.4.6 Threshold Detection Calculations
      7. 6.4.7 Light Resolution
    5. 6.5 Programming
      1. 6.5.1 I2C Bus Overview
        1. 6.5.1.1 Serial Bus Address
        2. 6.5.1.2 Serial Interface
      2. 6.5.2 Writing and Reading
        1. 6.5.2.1 High-Speed I2C Mode
        2. 6.5.2.2 Burst Read Mode
        3. 6.5.2.3 General-Call Reset Command
        4. 6.5.2.4 SMBus Alert Response (USON Variant)
  8. Register Maps
    1. 7.1 Register Descriptions
  9. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Electrical Interface
        1. 8.2.1.1 Design Requirements
          1. 8.2.1.1.1 Optical Interface
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Optomechanical Design (PicoStar Variant)
          2. 8.2.1.2.2 Optomechanical Design (USON Variant)
        3. 8.2.1.3 Application Curves (PicoStar Variant)
        4. 8.2.1.4 Application Curves (USON Variant)
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Soldering and Handling Recommendations (PicoStar Variant)
          1. 8.5.1.1.1 Solder Paste
          2. 8.5.1.1.2 Package Placement
          3. 8.5.1.1.3 Reflow Profile
          4. 8.5.1.1.4 Special Flexible Printed-Circuit Board (FPCB) Recommendations
          5. 8.5.1.1.5 Rework Process
        2. 8.5.1.2 Soldering and Handling Recommendations (USON Variant)
      2. 8.5.2 Layout Example
  10. Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Layout Guidelines

OPT4001-Q1 Placement Side View of
                    Packages Figure 8-9 Placement Side View of Packages

In the case of the USON package variant of the device, since the lighting sensitive area and the device pins are on opposite sides of each other, a conventional placement on the PCB provides good light collection. In the case of the PicoStar™ variant of the device, since the light sensitive area and the device pins are on the same side, a special arrangement as shown in Figure 8-9 is required to achieve good light collection. Typically, a thin flexible PCB with a hole or a cutout centered around the optical area is required for wide-angle light collection for the PicoStar™ variant. A regular PCB can be used but the amount of light collected and the field of view of light collection are not very good and generally not recommended. The cut out for the light collection can be of any shape with a large enough opening to let ample light fall on the light sensitive area. Figure 8-15 and Figure 8-16 show examples of two shapes which help maximize light collection. A circular cut out as large as manufacturing allows is acceptable but can restrict the field of view and reduce the light collection. Tools and documentation are available on TI's product folder to estimate the field of view based on the hole size.

TI highly recommends placing the decoupling capacitor close to the device, but remember that optically reflective surfaces of components also affect the performance of the design. Consider the three-dimensional geometry of all components and structures around the sensor to prevent unexpected results from secondary optical reflections. Placing capacitors and components at a distance of at least twice the height of the component is usually sufficient. The best optical layout is to place all close components on the opposite side of the PCB from the OPT4001-Q1. However, this approach is not practical for the constraints of every design.

The device layout is also critical for good SMT assembly. Two types of land pattern pads can be used for this package: solder mask defined pads (SMD) and non-solder mask defined pads (NSMD). SMD pads have a solder mask opening that is smaller than the metal pads, whereas, NSMD has a solder mask opening that is larger than the metal pad. Figure 8-10 illustrates these types of landing-pattern pads. SMD pads are preferred because these pads provide a more accurate soldering-pad dimension with the trace connections. For further discussion of SMT and PCB recommendations, see the Soldering and Handling Recommendations (USON Variant) section.

OPT4001-Q1 Solder Mask Defined Pad (SMD) and Non-Solder Mask Defined Pad (NSMD)Figure 8-10 Solder Mask Defined Pad (SMD) and Non-Solder Mask Defined Pad (NSMD)