DLPS178C may   2020  – july 2023 DLP4710LC

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  Storage Conditions
    3. 6.3  ESD Ratings
    4. 6.4  Recommended Operating Conditions
    5. 6.5  Thermal Information
    6. 6.6  Electrical Characteristics
    7. 6.7  Timing Requirements
    8. 6.8  Switching Characteristics
    9. 6.9  System Mounting Interface Loads
    10. 6.10 Physical Characteristics of the Micromirror Array
    11. 6.11 Micromirror Array Optical Characteristics
    12. 6.12 Window Characteristics
    13. 6.13 Chipset Component Usage Specification
    14. 6.14 Software Requirements
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Power Interface
      2. 7.3.2 Low-Speed Interface
      3. 7.3.3 High-Speed Interface
      4. 7.3.4 Timing
    4. 7.4 Device Functional Modes
    5. 7.5 Optical Interface and System Image Quality Considerations
      1. 7.5.1 Optical Interface and System Image Quality
        1. 7.5.1.1 Numerical Aperture and Stray Light Control
        2. 7.5.1.2 Pupil Match
        3. 7.5.1.3 Illumination Overfill
    6. 7.6 Micromirror Array Temperature Calculation
    7. 7.7 Micromirror Power Density Calculation
    8. 7.8 Micromirror Landed-On/Landed-Off Duty Cycle
      1. 7.8.1 Definition of Micromirror Landed-On and Landed-Off Duty Cycle
      2. 7.8.2 Landed Duty Cycle and Useful Life of the DMD
      3. 7.8.3 Landed Duty Cycle and Operational DMD Temperature
      4. 7.8.4 Estimating the Long-Term Average Landed Duty Cycle of a Product or Application
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1.      46
      2. 8.2.1 Design Requirements
      3. 8.2.2 Detailed Design Procedure
      4. 8.2.3 Application Curve
  10. 9 Power Supply Recommendations
    1. 9.1 DMD Power Supply Power-Up Procedure
    2. 9.2 DMD Power Supply Power-Down Procedure
    3. 9.3 Power Supply Sequencing Requirements
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Device Nomenclature
      3. 11.1.3 Device Markings
    2. 11.2 Related Links
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.6 Micromirror Array Temperature Calculation

GUID-8A1C7D11-9FE3-4FBD-B341-811E07E7AC1F-low.gif Figure 7-1 DMD Thermal Test Points

Micromirror array temperature cannot be measured directly, therefore it must be computed analytically from measurement points on the outside of the package, the package thermal resistance, the electrical power, and the illumination heat load. The relationship between array temperature and the reference ceramic temperature (thermal test TP1 in Figure 7-1) is provided by the following equations:

TARRAY = TCERAMIC + (QARRAY × RARRAY-TO-CERAMIC)
QARRAY = QELECTRICAL + QILLUMINATION

where

  • TARRAY = Computed array temperature (°C)
  • TCERAMIC = Measured ceramic temperature (°C) (TP1 location)
  • RARRAY-TO-CERAMIC = Thermal resistance of package specified in Section 6.5 from array to ceramic TP1 (°C/Watt)
  • QARRAY = Total DMD power on the array (W) (electrical + absorbed)
  • QELECTRICAL = Nominal electrical power (W)
  • QINCIDENT = Incident illumination optical power (W)
  • QILLUMINATION = (DMD average thermal absorptivity × QINCIDENT) (W)
  • DMD average thermal absorptivity = 0.4

The electrical power dissipation of the DMD is variable and depends on the voltages, data rates and operating frequencies. A nominal electrical power dissipation to use when calculating array temperature is 0.25 Watts. The absorbed power from the illumination source is variable and depends on the operating state of the micromirrors and the intensity of the light source. The equations shown above are valid for a single chip or multichip DMD system. It assumes an illumination distribution of 83.7% on the active array, and 16.3% on the array border.

The sample calculation for a typical projection application is as follows:

QINCIDENT = 9.4 W (measured)
TCERAMIC = 55.0°C (measured)
QELECTRICAL = 0.25 W
QARRAY = 0.25 W + (0.40 × 9.4 W) = 4.01 W
TARRAY = 55.0°C + (4.01 W × 1.1°C/W) = 59.4°C