SNVSC61A August   2022  – December 2022 LP5891-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Independent and Stackable Mode
        1. 8.3.1.1 Independent Mode
        2. 8.3.1.2 Stackable Mode
      2. 8.3.2 Current Setting
        1. 8.3.2.1 Brightness Control (BC) Function
        2. 8.3.2.2 Color Brightness Control (CC) Function
        3. 8.3.2.3 Choosing BC/CC for a Different Application
      3. 8.3.3 Frequency Multiplier
      4. 8.3.4 Line Transitioning Sequence
      5. 8.3.5 Protections and Diagnostics
        1. 8.3.5.1 Thermal Shutdown Protection
        2. 8.3.5.2 IREF Resistor Short Protection
        3. 8.3.5.3 LED Open Load Detection and Removal
          1. 8.3.5.3.1 LED Open Detection
          2. 8.3.5.3.2 Read LED Open Information
          3. 8.3.5.3.3 LED Open Caterpillar Removal
        4. 8.3.5.4 LED Short and Weak Short Circuitry Detection and Removal
          1. 8.3.5.4.1 LED Short/Weak Short Detection
          2. 8.3.5.4.2 Read LED Short Information
          3. 8.3.5.4.3 LSD Caterpillar Removal
    4. 8.4 Device Functional Modes
    5. 8.5 Continuous Clock Series Interface
      1. 8.5.1 Data Validity
      2. 8.5.2 CCSI Frame Format
      3. 8.5.3 Write Command
        1. 8.5.3.1 Chip Index Write Command
        2. 8.5.3.2 VSYNC Write Command
        3. 8.5.3.3 MPSM Write Command
        4. 8.5.3.4 Standby Clear and Enable Command
        5. 8.5.3.5 Soft_Reset Command
        6. 8.5.3.6 Data Write Command
      4. 8.5.4 Read Command
    6. 8.6 PWM Grayscale Control
      1. 8.6.1 Grayscale Data Storage and Display
        1. 8.6.1.1 Memory Structure Overview
        2. 8.6.1.2 Details of Memory Bank
        3. 8.6.1.3 Write a Frame Data into Memory Bank
      2. 8.6.2 PWM Control for Display
    7. 8.7 Register Maps
      1. 8.7.1  FC0
      2. 8.7.2  FC1
      3. 8.7.3  FC2
      4. 8.7.4  FC3
      5. 8.7.5  FC4
      6. 8.7.6  FC14
      7. 8.7.7  FC15
      8. 8.7.8  FC16
      9. 8.7.9  FC17
      10. 8.7.10 FC18
      11. 8.7.11 FC19
      12. 8.7.12 FC20
      13. 8.7.13 FC21
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 System Structure
        2. 9.2.1.2 SCLK Frequency
        3. 9.2.1.3 Internal GCLK Frequency
        4. 9.2.1.4 Line Switch Time
        5. 9.2.1.5 Blank Time Removal
        6. 9.2.1.6 BC and CC
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Chip Index Command
        2. 9.2.2.2 FC Registers Settings
        3. 9.2.2.3 Grayscale Data Write
        4. 9.2.2.4 VSYNC Command
        5. 9.2.2.5 LED Open, Short Read
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    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
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.3.5.4.3 LSD Caterpillar Removal

Figure 8-15 shows the LSD caterpillar issue caused by short LED. Suppose the LED0-1 is a short LED. When it scans to the line1 and the OUT1 is turned off, the OUT1 voltage is the same with scan line0 voltage because of the short path of the LED0-1. At this time, there is a current path from the line0 to the GND through the LED1-1 and SW1-1, which causes LED1-1 light unwanted.

Figure 8-15 LED Short Caterpillar

The LP5891-Q1 device implements internal circuits that can eliminate the caterpillar issue by short LEDs. As is shown in Figure 8-15, the LED short caterpillar is caused by the voltage of the Vclamp on the line. So it can be solved by adjusting the LSD_RM_EN (see FC3 for more details) to let the voltage drop of the LED1-1 be smaller than LED forward voltage.