DLPS021 September   2019

PRODUCTION DATA.

1. Features
2. Applications
3. Description
1.     Device Images
4. Revision History
5. Pin Configuration and Functions
6. Specifications
7. Detailed Description
8. Application and Implementation
1. 8.1 Application Information
2. 8.2 Typical Application
3. 8.3 Temperature Sensor Diode
9. Power Supply Recommendations
10. 10Layout
1. 10.1 Layout Guidelines
2. 10.2 Layout Example
1. 10.2.1 Layers
2. 10.2.2 Impedance Requirements
3. 10.2.3 Trace Width, Spacing
11. 11Device and Documentation Support
12. 12Mechanical, Packaging, and Orderable Information

• FQN|250

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

During a given period of time, the nominal 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 experiences a landed duty cycle very close to 100/0 during that time period. Likewise, when displaying pureblack, the pixel experiences a landed duty cycle very close to 0/100.

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 5.

### Table 5. Grayscale Value and Landed Duty Cycle

GRAYSCALE VALUE NOMINAL 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.

Use Equation 1 to calculate the landed duty cycle of a given pixel during a given time period

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

where

• Red_Cycle_%, represents the percentage of the frame time that red is displayed to achieve the desired white point
• Green_Cycle_% represents the percentage of the frame time that green is displayed to achieve the desired white point
• Blue_Cycle_%, represents the percentage of the frame time that blue is displayed to achieve the desired white point

For example, assume 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 nominal landed duty cycle for various combinations of red, green, blue color intensities would be as shown in Table 6 and Table 7.

CYCLE PERCENTAGE
RED GREEN BLUE
50% 20% 30%

### Table 7. Example Landed Duty Cycle for Full-Color

SCALE VALUE NOMINAL LANDED DUTY CYCLE
RED GREEN BLUE
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