SLVSEB3A June   2018  – January 2019 TLC6946 , TLC6948

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic of TLC6948 With 48-Multiplexing
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin 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 Switching Characteristics
    7. 7.7 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Pin Equivalent Input and Output Schematic Diagrams
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Built-In 16Kb Display Memory (SRAM)
      2. 9.3.2  GCLK Dual-Edge Operation
      3. 9.3.3  Programmable Constant-Sink Channel Current
        1. 9.3.3.1 Global Brightness Control (BC)
        2. 9.3.3.2 Select RIREF for a Given BC
      4. 9.3.4  Grayscale (GS) Function (PWM Control)
      5. 9.3.5  Serial Data Interface
      6. 9.3.6  LED-Open Detection (LOD)
      7. 9.3.7  Caterpillar Removal
      8. 9.3.8  Precharge FET
      9. 9.3.9  Thermal Shutdown
      10. 9.3.10 IREF Resistor Short Protection (ISP)
    4. 9.4 Device Functional Modes
      1. 9.4.1 Normal Operating Mode
      2. 9.4.2 Power-Save Mode (PSM)
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedures
        1. 10.2.2.1 Power Supply Voltage
        2. 10.2.2.2 Channel Current and Brightness Control
        3. 10.2.2.3 SCLK and GCLK Frequency
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Examples
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Related Links
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

12.1 Layout Guidelines

Place the decoupling capacitor near the VCC pin and GND plane.

Place the current-programming resistor, RIREF, close to the IREF pin and the GND pin.

Make the GND trace as wide as possible for large GND currents.

Routing between the LED cathode and the device OUTn pin must be as short and straight as possible to reduce wire inductance.

The thermal pad (QFN package) must be connected to the GND plane. Because the thermal pad is used as a power ground pin internally, there is a large current flow through this pad when all channels turn on. Furthermore, connect the thermal pad to a heat sink layer by thermal vias to reduce device temperature. One suggested thermal via pattern is shown in Layout Examples. For more information about suggested thermal via pattern and via size, see PowerPAD Thermally Enhanced Package.

MOSFETs must be placed in the in the middle of the board, which should be laid out as symmetrically as possible.