TIDUF22 January   2023

 

  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
      1. 2.2.1  6-W Auxiliary Power Supply
      2. 2.2.2  AC Input Current Sensing
      3. 2.2.3  DC Bus Voltage Sensing
      4. 2.2.4  AC Input Voltage Sensing
      5. 2.2.5  GaN Driving
      6. 2.2.6  Inrush Current Protection at Powering On
      7. 2.2.7  Overcurrent Protection
      8. 2.2.8  AC Input Undervoltage Protection
      9. 2.2.9  DC Bus Overvoltage Protection
      10. 2.2.10 GaN Temperature Monitor and Protection
      11. 2.2.11 Heat Sink Temperature Monitor and Protection
      12. 2.2.12 UART Heartbeat Report
      13. 2.2.13 Motor Control Interface
    3. 2.3 Highlighted Products
      1. 2.3.1 LMG352xR030
      2. 2.3.2 TMS320F28002x
      3. 2.3.3 UCC2871x
      4. 2.3.4 TLV906x
      5. 2.3.5 TPS54308
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements and Assembly
      1. 3.1.1 Test Equipment Requirements
    2. 3.2 Software Requirements
    3. 3.3 Test Setup
    4. 3.4 Test Results
      1. 3.4.1 Test Procedures
        1. 3.4.1.1 Test Procedures Under 90 VAC
        2. 3.4.1.2 Test Procedures Under 220 VAC
    5. 3.5 Performance Data: Efficiency, iTHD, and Power Factor
    6. 3.6 Functional Waveforms
      1. 3.6.1  Test Under 90 VAC, 800-Ω Load
      2. 3.6.2  Power-On Sequence Test Under 220 VAC
      3. 3.6.3  Waveform With Heavy Load
      4. 3.6.4  Buck Auxiliary Power Supply Tests
      5. 3.6.5  AC Drop Test
      6. 3.6.6  GaN Switching Performance
      7. 3.6.7  Thermal Test
      8. 3.6.8  Power-Off Sequence
      9. 3.6.9  Surge Test
      10. 3.6.10 Conducted Emission Test
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author

3.6.10 Conducted Emission Test

Figure 3-22 shows the conducted Emission test result with a 1.6-kw load. The board was tested with an additional CM choke at DC output (to overcome a long load cable and a large resistor load), and a shield layer for the boost inductor. The result shows the board can pass the Class B limit of EN55032. Noise level at 11.42 MHz is 59.17 (54.17 dBμV+5 dBμV of calibration), margin is a little small as usually 6 dB is needed; however, housing (the outdoor unit of air conditioner usually has a metal housing) and a short load cable further reduces noise to Line Impedance Stabilization Network (LISN), and gives much more margin.

GUID-20221208-SS0I-7JDR-8RN0-HBTZDS90R377-low.pngFigure 3-22 Conducted Emission Test, EN55032 Class B