DLPS228D October   2021  – October 2024 DLP160CP

PRODUCTION DATA  

  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. 5.5  Thermal Information
    6. 5.6  Electrical Characteristics
    7. 5.7  Timing Requirements
    8. 5.8  Switching Characteristics
    9. 5.9  System Mounting Interface Loads
    10. 5.10 Micromirror Array Physical Characteristics
    11. 5.11 Micromirror Array Optical Characteristics
    12. 5.12 Window Characteristics
    13. 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 Power Interface
      2. 6.3.2 Low-Speed Interface
      3. 6.3.3 High-Speed 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
    7. 6.7 Micromirror Power Density Calculation
    8. 6.8 Micromirror Landed-On/Landed-Off Duty Cycle
      1. 6.8.1 Definition of Micromirror Landed-On/Landed-Off Duty Cycle
      2. 6.8.2 Landed Duty Cycle and Useful Life of the DMD
      3. 6.8.3 Landed Duty Cycle and Operational DMD Temperature
      4. 6.8.4 Estimating the Long-Term Average Landed Duty Cycle of a Product or Application
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Typical Application—nHD Mode
      2. 7.2.2 Typical Application—HD Mode
      3. 7.2.3 Design Requirements
      4. 7.2.4 Detailed Design Procedure
      5. 7.2.5 Application Curve
  9. 8 Power Supply Recommendations
    1. 8.1 Power Supply Power-Up Procedure
    2. 8.2 Power Supply Power-Down Procedure
    3. 8.3 Power Supply Sequencing Requirements
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
      2. 10.1.2 Device Nomenclature
      3. 10.1.3 Device Markings
    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
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

6.8.4 Estimating the Long-Term Average Landed Duty Cycle of a Product or Application

During a given period of time, the landed duty cycle of a given pixel follows from the image content being displayed by that pixel.

For example, in the simplest case, when displaying pure-white on a given pixel for a given time period, that pixel will experience close to a 100/0 landed duty cycle during that time period. Likewise, when displaying pure-black, the pixel will experience close to a 0/100 landed duty cycle.

Between the two extremes (ignoring for the moment color and any image processing that may be applied to an incoming image), the landed duty cycle tracks one-to-one with the gray scale value, as shown in Table 6-1.

Table 6-1 Grayscale Value and Nominal Landed Duty Cycle
Grayscale Value Landed Duty Cycle
0% 0/100
10% 10/90
20% 20/80
30% 30/70
40% 40/60
50% 50/50
60% 60/40
70% 70/30
80% 80/20
90% 90/10
100% 100/0

Accounting for color rendition (but still ignoring image processing) requires knowing both the color intensity (from 0% to 100%) for each constituent primary color (red, green, and/or blue) for the given pixel as well as the color cycle time for each primary color, where “color cycle time” is the total percentage of the frame time that a given primary must be displayed in order to achieve the desired white point.

During a given period of time, the landed duty cycle of a given pixel can be calculated as follows:

Equation 1. Landed Duty Cycle = (Red_Cycle_% × Red_Scale_Value) + (Green_Cycle_% × Green_Scale_Value) + (Blue_Cycle_%×Blue_Scale_Value)

where

Red_Cycle_%, Green_Cycle_%, and Blue_Cycle_% represent the percentage of the frame time that red, green, and blue are displayed (respectively) to achieve the desired white point.

For example, assuming that the red, green and blue color cycle times are 50%, 20%, and 30% respectively (in order to achieve the desired white point), then the landed duty cycle for various combinations of red, green, blue color intensities would be as shown in Table 6-2.

Table 6-2 Example Nominal Landed Duty Cycle for Full-Color Pixels
Red Cycle Percentage Green Cycle Percentage Blue Cycle Percentage
50% 20% 30%
Red Scale Value Green Scale Value Blue Scale Value Landed Duty Cycle
0% 0% 0% 0/100
100% 0% 0% 50/50
0% 100% 0% 20/80
0% 0% 100% 30/70
12% 0% 0% 6/94
0% 35% 0% 7/93
0% 0% 60% 18/82
100% 100% 0% 70/30
0% 100% 100% 50/50
100% 0% 100% 80/20
12% 35% 0% 13/87
0% 35% 60% 25/75
12% 0% 60% 24/76
100% 100% 100% 100/0

The last factor to account for in estimating the landed duty cycle is any applied image processing. Within the DLP controller DLPC3421ZVB, the two functions which affect the landed duty cycle are gamma and IntelliBright™.

Gamma is a power function of the form Output_Level = A × Input_LevelGamma, where A is a scaling factor that is typically set to 1.

In the DLPC3421ZVB controller, gamma is applied to the incoming image data on a pixel-by-pixel basis. A typical gamma factor is 2.2, which transforms the incoming data as shown in Figure 6-2.

DLP160CP Example of Gamma = 2.2 Figure 6-2 Example of Gamma = 2.2

From Figure 6-2, if the gray scale value of a given input pixel is 40% (before gamma is applied), then gray scale value will be 13% after gamma is applied. Therefore, it can be seen that since gamma has a direct impact displayed gray scale level of a pixel, it also has a direct impact on the landed duty cycle of a pixel.

The content adaptive illumination control (CAIC) and local area brightness boost (LABB) of the IntelliBright algorithm also apply transform functions on the gray scale level of each pixel.

But while the amount of gamma applied to every pixel of every frame is constant (the exponent, gamma, is constant), CAIC and LABB are both adaptive functions that can apply different amounts of either boost or compression to every pixel of every frame.

Consideration must also be given to any image processing which occurs before the DLPC3421ZVB controller.