DLPS284 December   2025 DLP3940S-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  Storage Conditions
    3. 5.3  ESD Ratings
    4. 5.4  Recommended Operating Conditions
    5.     11
    6. 5.5  Thermal Information
    7. 5.6  Electrical Characteristics
    8. 5.7  Switching Characteristics
    9. 5.8  Timing Requirements
    10.     16
    11. 5.9  System Mounting Interface Loads
    12.     18
    13. 5.10 Micromirror Array Physical Characteristics
    14.     20
    15. 5.11 Micromirror Array Optical Characteristics
    16. 5.12 Window Characteristics
    17. 5.13 Chipset Component Usage Specification
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 SubLVDS Data Interface
      2. 6.3.2 Low Speed Interface for Control
      3. 6.3.3 Power Interface
      4. 6.3.4 Timing
    4. 6.4 Device Functional Modes
    5. 6.5 Optical Interface and System Image Quality Considerations
      1. 6.5.1 Numerical Aperture and Stray Light Control
      2. 6.5.2 Pupil Match
      3. 6.5.3 Illumination Overfill
    6. 6.6 Micromirror Array Temperature Calculation
      1. 6.6.1 Monitoring Array Temperature Using the Temperature Sense Diode
    7. 6.7 Micromirror Power Density Calculation
    8. 6.8 Window Aperture Illumination Overfill Calculation
    9. 6.9 Micromirror Landed-On/Landed-Off Duty Cycle
      1. 6.9.1 Definition of Micromirror Landed-On/Landed-Off Duty Cycle
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Application Overview
      2. 7.2.2 Input Image Resolution
      3. 7.2.3 Reference Design
      4. 7.2.4 Application Mission Profile Consideration
      5. 7.2.5 Design Requirements
      6. 7.2.6 Detailed Design Procedure
    3. 7.3 Temperature Sensing
      1. 7.3.1 Temperature Sensing Diode
        1. 7.3.1.1 Temperature Sense Diode Theory
  9. 8 Power Supply Recommendations
    1. 8.1 DMD Power Supply Power-Up Procedure
    2. 8.2 DMD Power Supply Power-Down Procedure
    3. 8.3 DMD Power Supply Sequencing Requirements
  10. 9 Layout
    1. 9.1 Layout Guidelines
  11. 10Device and Documentation Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Device Support
      1. 10.2.1 Device Nomenclature
      2. 10.2.2 Device Markings
    3. 10.3 Documentation Support
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

6.8 Window Aperture Illumination Overfill Calculation

The amount of optical overfill on the critical area of the window aperture cannot be measured directly. For systems with uniform illumination on the array the amount is determined using the total measured incident optical power on the DMD, and the ratio of the total optical power on the DMD that is on the defined critical area. The optical model is used to determine the percent of optical power on the window aperture critical area and estimate the size of the area.

  • QAP-ILL = [QINCIDENT × OPAP_ILL_RATIO] ÷ AAP_ILL (W/cm2)

where:

  • QAP-ILL = window aperture illumination overfill (W/cm2)
  • QINCIDENT = total incident optical power on the DMD (Watts) (measured)
  • OPAP_ILL_RATIO = ratio of the optical power on the critical area of the window aperture to the total optical power on the DMD (optical model)
  • AAP-ILL = size of the window aperture critical area (cm2) (data sheet)
  • OPCA_RATIO = percent of the window aperture critical area with incident optical power (%) (optical model)

Sample calculation:


DLP3940S-Q1

Figure 6-3 Window Aperture Overfill Example

See the above figure for the length of the critical aperture.

Equation 12. QINCIDENT = 12.1 W (measured)
Equation 13. OPAP_ILL_RATIO = 0.312% (optical model)
Equation 14. OVCA_RATIO = 25% (optical model)
Equation 15. Length of the window aperture for critical area = 0.9802 cm (data sheet)
Equation 16. Width of critical area = 0.050 cm (data sheet)
Equation 17. AAP-ILL = 0.9802 cm × 0.050 cm = 0.04901 cm2
Equation 18. QAP-ILL = (12.1 W × 0.00312) ÷ (0.04901 cm2 × 0.25) = 3.08 W/cm2 (W/cm2)