SLVAFI4 july 2023 LP5890 , LP5891 , TLC6983 , TLC6984
1 Introduction
Table 1-1 shows the typical, basic design parameters table for an LED cinema screen from the perspective of a product manager. Based on the key information of LED panel module resolution, frame rate, color depth, and refresh rate, the system engineer needs to design some basic parameters related to the LED driver that are discussed more in detail throughout this document.
| Type | Parameter | Value |
|---|---|---|
| Physical Parameter | LED Screen Resolution | 4K (3840 × 2160) |
| LED Screen Pitch (mm) | 2.5 | |
| LED Box Module Resolution (dots) | 384 × 216 | |
| LED Box Module Size (Width×Hight)/(mm) | 960 × 540 | |
| LED Panel Module Resolution (dots) | 96 × 108 | |
| LED Panel Module Size (Width×Hight)/(mm) | 240 × 270 | |
| Optical Parameter | Frame Rate (Hz) | 60/120 |
| PWM Resolution/Grayscale Intensity/Color depth (bits) | 14 to 16 | |
| Refresh Rate (Hz) | 1920 to 7680 | |
| Typ./Max Brightness (nit) | 48/300 (Max 500 nit at HDR cinema mode) | |
| Minimum Brightness (nit) | 0.03 | |
| Black level | 0.005 nit or match the black level of the DCI projector | |
| Contrast Ratio (In darkroom) | ∞ : 1 | |
| Color Temperature (K) | 6000 | |
| Color gamut | DCI-P3 | |
| White Point | D63 (Xw 0.3140, Yw 0.3510) | |
| Gamma coefficient | 2.6 |
Figure 1-1 shows a typical 4K resolution (3840 × 2160) LED Display screen and the corresponding breakdown drawing. Within the LED panel module (96 × 108), the LED panel module is further decomposed into 18 sub-blocks (6 groups with each group having 3 sub-blocks) with each block having 32 RGB channels and 18 scans (32 × 18). The TLC6983 48x16 Common Cathode Matrix LED Display Driver with Ultra Low Power data sheet specifies that the TLC6983 can use dual devices in stackable mode to supports 32 × 32 RGB pixels (32 RGB channels and 32 scans). Why does the system engineer only uses 18 scans? What are the design considerations to consider? These questions are discussed in depth throughout this application note.
Figure 1-1 A Typical 4K LED Display With
the Breakdown Drawing