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

3.2.4 Stability

Figure 3-14 through Figure 3-16 show the bode diagram of the LM5155-Q1 SEPIC voltage regulator in this reference design. All conditions show stable operation with enough phase margin. However, for a stable operation at minimum input voltage at high load current, TI recommends adding more output capacitance or placing an high ESR capacitor (for damping) in parallel to the SEPIC coupling capacitor.

GUID-57087D58-E5DF-4F3C-888C-BD655BCD2DEB-low.pngFigure 3-14 Bode Plot: 13.5-Vin, 0.8-A Load
GUID-DF90685F-78B1-41CD-910E-5C404F45726B-low.pngFigure 3-15 Bode Plot: 9-Vin, 0.8-A Load
GUID-892AD820-82A9-48D1-AF5C-ABE0B485536D-low.pngFigure 3-16 Bode Plot: 6-Vin, 0.8-A Load