TIDUEY2 September   2021

 

  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 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 UCC28951-Q1
      2. 2.3.2 UCC27524-Q1
      3. 2.3.3 UCC21530-Q1
      4. 2.3.4 INA293-Q1
      5. 2.3.5 SN6505B-Q1
    4. 2.4 System Design Theory
      1. 2.4.1 Power Budget
      2. 2.4.2 Transformer Calculations
      3. 2.4.3 Primary Side MOSFET Losses
      4. 2.4.4 Shim Inductor
      5. 2.4.5 Output Inductor Selection
      6. 2.4.6 Selection of Synchronous MOSFETs
      7. 2.4.7 UCC28951-Q1 Configuration
        1. 2.4.7.1 Current Sense Network
        2. 2.4.7.2 Voltage and Current Regulation Loop
        3. 2.4.7.3 Adaptive Delay DELAB, DELCD, and ADEL
        4. 2.4.7.4 Adaptive Delay DELEF, ADELEF
        5. 2.4.7.5 Minimum Pulse (TMIN)
        6. 2.4.7.6 Switching Frequency
        7. 2.4.7.7 Slope Compensation
        8. 2.4.7.8 Dynamic SR ON and OFF Control
  8. 3Hardware, Testing Requirements, and Test Results
    1. 3.1 Hardware
    2. 3.2 Testing and Results
      1. 3.2.1 Test Setup
      2. 3.2.2 Test Results
        1. 3.2.2.1 Start-up and Power Down
        2. 3.2.2.2 Output Voltage Ripple
        3. 3.2.2.3 Full Bridge Primary Switch Node Voltages
          1. 3.2.2.3.1 Under 10-A Load
          2. 3.2.2.3.2 Under 100-A Load
        4. 3.2.2.4 Efficiency
        5. 3.2.2.5 Load Regulation (VIN = 250 V, VIN = 400 V)
        6. 3.2.2.6 Load Transient Response
        7. 3.2.2.7 Thermal Images
  9. 4Design Files
    1. 4.1 Schematics
    2. 4.2 BOM
    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
    7. 4.7 Support Resources
  10. 5Related Documentation
  11. 6Terminology
  12. 7About the Author

Description

This reference design is a 3.6-kW, automotive 400-V to 12-V Unidirectional Converter which converts the 200-V to 450-V DC input to 12-V, 300-A maximum output. A circuit breaker is applied for overcurrent and overvoltage protections. The converter is designed with SiC MOSFETs on the high-voltage side and driven by 5.7-kVRMS, reinforced isolated dual-channel gate drivers. The enhanced phase-shifted full-bridge controller implements programmable delays which ensure Zero Voltage Switching (ZVS) over a wide range of operating conditions. It offers multiple light-load management features including burst mode and dynamic SR on and off control when transitioning in and out of Discontinuous Current Mode (DCM) operation. The output implements synchronous rectification, which enables fast transient response and a high loop bandwidth.