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

8.4.2.4 LED-Open Detection (LOD), LED-Short Detection (LSD), And Thermal Error Flag (TEF)

LOD detects a fault caused by an LED open circuit or a short from OUTRn, -Gn, -Bn to ground by comparing the OUTRn, -Gn, -Bn voltage to the LOD detection threshold voltage level set in the control data latch (Table 4). If the OUTRn, -Gn, -Bn voltage is lower than the programmed voltage, that output LOD bit is set to 1 to indicate an open LED. Otherwise, the LOD bit is set to 0. LOD data are only valid for outputs programmed to be on. LOD data for outputs programmed to be off are always 0.

LSD data detects a fault caused by a shorted LED by comparing the OUTRn, -Gn, -Bn voltage to the LSD detection threshold voltage level set in the control data latch (Table 4). If the OUTRn, -Gn, -Bn voltage is higher than the programmed voltage, that output LOD bit is set to 1 to indicate a shorted LED. Otherwise, the LSD bit is set to 0. LSD data are only valid for outputs programmed to be on. LSD data for outputs programmed to be off are always 0.

LOD and LSD data are not valid until 1 μs after the falling edge of BLANK. Therefore, BLANK must be low for at least 1 μs before going high. At the rising edge of BLANK, the LOD and LSD detection data are latched in the LOD-LSD holder. Changes in the LOD or LSD data while BLANK is low are directly connected to the output of the LOD-LSD holder, but are only valid 1 μs after the change. The rising edge of LAT transfers the output data of the LOD-LSD holder to the common shift register.

As shown in Table 5, LOD and LSD data cannot be checked simultaneously. LOD and LSD data are not valid when TEF is active because all outputs are forced off.

The TEF bit indicates that the device junction temperature exceeds the temperature threshold (TTEF = 165°C, typ). The TEF bit also indicates that the device has turned off all drivers to avoid overheating. The device automatically turns the drivers back on when the device temperature decreases to less than TTEF – THYS. The TEF data are held in the TEF holder latch until the TEF data are loaded into the common shift register by the rising edge of LAT. If the device temperature falls below TTEF – THYS when LAT goes high, the TEF data in the TEF holder become 0. If the device temperature is not below TTEF – THYS when LAT goes high, then the TEF data remain 1. Table 5 shows a truth table for LOD, LSD, and TEF. Figure 33 to Figure 36 show different examples of LOD, LSD, and TEF operation.

Table 5. LOD, LSD, and TEF Truth Table

SID DATA CONDITION
LED OPEN DETECTION
(LOD, Voltage Select Data =
0h to 3h)		 LED SHORT DETECTION
(LSD, Voltage Select Data = 4h to 7h)		 THERMAL ERROR FLAG (TEF)
0 LED is not open or the output is off
(VOUTRn/Gn/Bn is greater than the voltage selected by the detection voltage select bit in the
control data latch)		 LED is not shorted or the output is off
(VOUTRn/Gn/Bn is less than or equal to the voltage selected by the detection voltage select bit in the
control data latch)		 Junction temperature is lower than the detect temperature (TTEF) before TEF is undetected or the detect temperature (TTEF – THYS) after TEF is detected
1 LED is open or shorted to GND
(VOUTRn/Gn/Bn is less than or equal to the voltage selected by the detection voltage select bit in the
control data latch)		 LED terminal is short or OUTn is short to higher voltage (VOUTn is greater than The selected voltage by detection voltage select bit in the
control data latch)		 Junction temperature is higher than the detect temperature (TTEF)