ZHCU578 October   2018

 

  1.    说明
  2.    资源
  3.    特性
  4.    应用
  5.    设计图像
  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 TPS92692-Q1
    3. 2.3 LM74700
    4. 2.4 System Design Theory
      1. 2.4.1 Design Procedure
        1. 2.4.1.1  Operating Parameters, Duty Cycle
        2. 2.4.1.2  Setting the Switching Frequency
        3. 2.4.1.3  Inductor Value Calculation
        4. 2.4.1.4  Peak Inductor Current
        5. 2.4.1.5  Calculating RIS (R9)
        6. 2.4.1.6  Minimum Output Capacitance
        7. 2.4.1.7  Setting the LED Current
        8. 2.4.1.8  Soft-Start Capacitor
        9. 2.4.1.9  Overvoltage Protection (OVP)
        10. 2.4.1.10 Main N-Channel MOSFET Selection
        11. 2.4.1.11 Rectifier Diode Selection
        12. 2.4.1.12 Thermal Protection
      2. 2.4.2 Designing for Low EMI
        1. 2.4.2.1 EMI Performance
        2. 2.4.2.2 EMI Filter Design
          1. 2.4.2.2.1 Additional EMI Considerations
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Required Hardware and Software
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 Nominal Operation Waveforms
          1. 3.2.2.1.1 Loop Stability Measurements Block Diagram
        2. 3.2.2.2 Efficiency and Line Regulation: Done for different power level for Boost (Hi Beam and Lo Beam) or Boost to Battery for Lo Beam only
        3. 3.2.2.3 Thermal Scan
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
    3. 4.3 Layout Prints
    4. 4.4 Altium Project
    5. 4.5 Gerber Files
    6. 4.6 Assembly Drawings
  10. 5Related Documentation
    1. 5.1 商标

3.2.2.3 Thermal Scan

Figure 19 shows a thermal scan of the board running at a room temperature (≈ 24°C) with no air flow. Table 2 lists measured temperatures of key components.

TIDA-050002 Thermal_24C.gifFigure 19. Thermal Scan With Heat Sink—Top-View (Power Components): VIN = 13 V, HB/LB Mode (55 W), ILED = 1.25 A

Table 2. Component Temperatures

CURSOR COMPONENT TEMPERATURE (°C)
1 Q3 66.2
2 D3 56.6
3 R9 52.3

Figure 21 shows a thermal scan of the board running at a elevated temperature (≈ 70°C) with no air flow. Table 3 lists measured temperatures of key components.

TIDA-050002 PCB_Heat_Sink.gifFigure 20. Picture of Heatsink on Board
TIDA-050002 Thermal_Picture.gifFigure 21. Thermal Scan—Top-View (Power Components): VIN = 13 V, HB/LB mode (55 W), ILED = 1.25 A

Table 3. Component Temperatures

CURSOR COMPONENT TEMPERATURE (°C)
1 Q3 114.3
2 D3 100.8
3 R9 91.3