TIDUFB1 December   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Terminology
    2. 1.2 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Control System Design Theory
        1. 2.2.1.1 PWM Modulation
        2. 2.2.1.2 Current Loop Model
        3. 2.2.1.3 DC Bus Regulation Loop
        4. 2.2.1.4 DC Voltage Balance Controller
    3. 2.3 Highlighted Products
      1. 2.3.1 TMS320F280013x
      2. 2.3.2 UCC5350
      3. 2.3.3 AMC1350
      4. 2.3.4 TMCS1123
      5. 2.3.5 UCC28750
      6. 2.3.6 LM25180
      7. 2.3.7 ISOTMP35
      8. 2.3.8 TLV76133
      9. 2.3.9 TLV9062
    4. 2.4 Hardware Design
      1. 2.4.1  Inductor Design
      2. 2.4.2  Bus Capacitor Selection
      3. 2.4.3  Input AC Voltage Sensing
      4. 2.4.4  Output DCBUS Voltage Sensing
      5. 2.4.5  Auxiliary Power Supply
      6. 2.4.6  Isolated Power Supply
      7. 2.4.7  Inductor Current Sensing
      8. 2.4.8  Gate Driver
      9. 2.4.9  Isolated Temperature Sensing
      10. 2.4.10 Overcurrent, Overvoltage Protection (CMPSS)
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 Getting Started Hardware
        1. 3.1.1.1 Board Overview
        2. 3.1.1.2 Test Equipment
    2. 3.2 Software Requirements
      1. 3.2.1 Getting Started GUI
        1. 3.2.1.1 Test Setup
        2. 3.2.1.2 Overview of a GUI Software
        3. 3.2.1.3 Procedures of Test With GUI
      2. 3.2.2 Getting Started Firmware
        1. 3.2.2.1 Opening the Project Inside Code Composer Studio™
        2. 3.2.2.2 Project Structure
        3. 3.2.2.3 Test Setup
        4. 3.2.2.4 Running Project
          1. 3.2.2.4.1 INCR_BUILD 1: Open Loop
            1. 3.2.2.4.1.1 Setting, Building, and Loading the Project
            2. 3.2.2.4.1.2 Setup Debug Environment Windows
            3. 3.2.2.4.1.3 Using Real-Time Emulation
            4. 3.2.2.4.1.4 Running Code (Build 1)
          2. 3.2.2.4.2 INCR_BUILD 2: Closed Current Loop
            1. 3.2.2.4.2.1 Running Code (Build 2)
            2. 3.2.2.4.2.2 Building and Loading the Project and Setting Up Debug
          3. 3.2.2.4.3 INCR_BUILD 3: Closed Voltage and Current Loop
            1. 3.2.2.4.3.1 Building and Loading the Project and Setting Up Debug
            2. 3.2.2.4.3.2 Running Code (Build 3)
          4. 3.2.2.4.4 INCR_BUILD 4: Closed Balance, Voltage, and Current Loop
            1. 3.2.2.4.4.1 Building and Loading the Project and Setting Up Debug
            2. 3.2.2.4.4.2 Running Code (Build 4)
    3. 3.3 Test Results
      1. 3.3.1  IGBT Gate Rising and Falling Time
      2. 3.3.2  Power On Sequence
      3. 3.3.3  PFC Started by GUI
      4. 3.3.4  Zero Crossing Under 380VAC, 9kW
      5. 3.3.5  Current Ripple Under 380VAC,10kW
      6. 3.3.6  10kW Load Test With Grid Power
      7. 3.3.7  9kW Load Test With AC Power Source
      8. 3.3.8  Power Analyzer Results
      9. 3.3.9  Thermal Performance
      10. 3.3.10 Voltage Short Interrupt Test
      11. 3.3.11 Efficiency, iTHD, and Power Factor Results
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 Bill of Material (BOM)
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

UCC28750

UCC28750 is a highly-integrated current-mode, continuous-conduction-capable, PWM controller optimized for high-performance, low standby power, and cost-effective offline flyback converter applications using an optocoupler. During light-load conditions, the device enters frequency foldback and burst modes, improving light-load efficiency. The burst-mode algorithm used in UCC28750 controls the minimum effective switching frequency to prevent audible noise during light-load conditions. Frequency dithering improves EMI performance, and is active in normal, frequency foldback, and power boost operations.

UCC28750 provides protection features that enable a robust converter design with minimal external components. Output over-power protection (OPP) and cycle-by-cycle overcurrent limit protect the load and power-stage components from electrical stress. Overvoltage and under-voltage lockout (OVLO and UVLO) prevent switching in unwanted input conditions. The FLT pin provides line brown-out sensing and protection, or external overtemperature and overvoltage protection, depending on the device variant. The FLT pin is also used to disable the device through external control by pulling the pin to ground, regardless of the device variant.