TIDUED7A November   2018  – November 2022

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 LM5155-Q1
      2. 2.2.2 TPS92610-Q1, TPS92611-Q1
    3. 2.3 System Design Theory
      1. 2.3.1  PCB and Form Factor
      2. 2.3.2  Input Protection
      3. 2.3.3  EMI Filter
      4. 2.3.4  LM5155-Q1 Voltage Regulator
      5. 2.3.5  Tail Light (2x TPS92611-Q1)
      6. 2.3.6  Stop Light (2x TPS92610-Q1)
      7. 2.3.7  Turn Light (TPS92610-Q1)
      8. 2.3.8  Backup Light
      9. 2.3.9  Enabling Light Functions
      10. 2.3.10 Diagnostic
      11. 2.3.11 LED Load
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware
    2. 3.2 Testing and Results
      1. 3.2.1 Startup / Shutdown
      2. 3.2.2 Steady State Operation
      3. 3.2.3 Load Transient Response
      4. 3.2.4 Stability
      5. 3.2.5 Efficiency
      6. 3.2.6 Electromagnetic Compatibility (EMC)
        1. 3.2.6.1 Conducted Emissions
        2. 3.2.6.2 Radiated Emissions
      7. 3.2.7 Thermal Performance
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 PCB Layout Recommendations
      1. 4.3.1 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Related Documentation
  11. 6Trademarks
  12. 7About the Author
  13. 8Revision History

2.3.9 Enabling Light Functions

In most vehicles, the different light functions get activated by providing a power signal coming from the body control module (BCM). The power signals provide power to the system and also control the enable pins of the LED driver ICs which results in independent function of the output channels by applying power to its input supply lines. Figure 2-11 shows the schematic of the circuit. Diodes D7 through D10 are for reverse polarity protection. The resistors and capacitors forms a LC-filter on each channel which creates a short delay for enabling the LED-drivers.

Figure 2-11 Schematic of Enabling Circuit

For systems where CAN or LIN communication is available, one power line from the BCM to the LED driver module is sufficient, and a microcontroller can be used to enable the individual light functions.