SBVS129A May   2009  – July 2018 TLC5952

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Circuit (Multiple Daisy-Chained TLC5952s)
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Pin Equivalent Input and Output Schematic Diagrams
    2. 7.2 Test Circuits
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Maximum Constant-Sink-Current Value
      2. 8.3.2 Global Brightness Control (BC) Function: Sink-Current Control
      3. 8.3.3 Constant-Current Output On-Off Control
    4. 8.4 Device Functional Modes
      1. 8.4.1 LOD, LSD, and TEF Operation
      2. 8.4.2 Register and Data Latch Configuration
        1. 8.4.2.1 Output On-Off Data Latch
        2. 8.4.2.2 Control-Data Latch
        3. 8.4.2.3 Status Information Data (SID)
        4. 8.4.2.4 LED-Open Detection (LOD), LED-Short Detection (LSD), And Thermal Error Flag (TEF)
        5. 8.4.2.5 Thermal Shutdown (TSD)
        6. 8.4.2.6 Noise Reduction
  9. 9 Power Supply Recommendations
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Community Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.2 Global Brightness Control (BC) Function: Sink-Current Control

The TLC5952 is able to adjust the output current of each of the three color groups OUTR0–OUTR7, OUTG0–OUTG7, and OUTB0–OUTB7. This function is called global brightness control (BC). The BC function allows users to adjust the global brightness of LEDs connected to the three output groups (OUTR0–OUTR7, OUTG0–OUTG7, and OUTB0–OUTB7). All color group output currents can be adjusted in 128 steps from 0% to 100% of the maximum output current, IOLCMax. The brightness control data are entered into the TLC5952 via the serial interface. When the BC data change, the output current also changes immediately. When the device is powered on, the data in the common shift register and the control data latch are not set to any default values. Therefore, BC data must be written to the control data latch before turning on the constant-current output.

Equation 2 determines the output sink current for each color group. Table 2 summarizes the BC data versus current ratio and set current value.

Equation 2. TLC5952 q_iout_ma_bvs129.gif

where

  • IOLCMax = the maximum channel current for each channel determined by R IREF
  • BCR, -G, -B = the global brightness control value in the control data latch for each output color group

Table 2. BC Data vs Current Ratio and Set-Current Value

BC DATA
(Binary)		 BC DATA
(Decimal)		 BC DATA
(Hex)		 RATIO OF OUTPUT CURRENT TO IOLCMax
(mA, Typical)		 IOUT, mA
(IOLCMax = 35 mA, Typical)		 IOUT, mA
(IOLCMax = 2 mA, Typical)
000 0000 0 00 0 0 0
000 0001 1 01 0.8 0.28 0.02
000 0010 2 02 1.6 0.55 0.03
... ... ... ... ... ...
111 1101 125 7D 98.4 34.45 1.97
111 1110 126 7E 99.2 34.72 1.98
111 1111 127 7F 100 35 2