TIDUF59 March   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 PFC Inductance Design
      2. 2.2.2 Configuration of CS pin in LMG3622
      3. 2.2.3 AHB Topology and the VCC Design
      4. 2.2.4 LMG2610 for AHB Topology
    3. 2.3 Highlighted Products
      1. 2.3.1 UCC28056
      2. 2.3.2 LMG3622
      3. 2.3.3 LMG2610
  9. 3Hardware, Test Requirements, and Test Results
    1. 3.1 Hardware
    2. 3.2 Test Setup
    3. 3.3 Test Results
      1. 3.3.1 Switching Waveform
        1. 3.3.1.1 Switching Waveform on the PFC Stage
        2. 3.3.1.2 Switching Waveform on the AHB Stage
      2. 3.3.2 Efficiency Test Result
      3. 3.3.3 Thermal Test Result
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 Layout Prints [Optional Section]
    2. 4.2 Tools
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

1 System Description

The TIDA-050074 reference design supports AC 100V–240V, 50Hz–60Hz input voltage, and provides DC 5V and 9V, 3A; 15V, 20V; and 28V, 5A output power. The design is based on low cost, high efficiency, and high power density with TM PFC + AHB topology. The ferrite core size was designed with RM10 for both PFC inductance and AHB transformer. The power supply dimensions are 50mm × 73mm × 23mm, and the power density is 27.33W/in3.

The UCC28056 is utilized for TM boost PFC topology which supports TM and discontinuous conduction mode (DCM) operation for the PFC stage. To simplify the circuit, the system was designed without AUX winding. This design employs the LMG3622 (120mΩ GaN HEMT with driver integrated) for overall device reliability.

The system can run at a higher frequency because of the lower switching loss on GaN devices. This ability leads to a lower inductance value with less turns and thicker wires to increase overall efficiency. The PFC is turned off at 5V and 9V output condition to provide a more efficiency result.

The TI GaN driver is integrated with overcurrent protection (OCP), short-circuit protection (SCP), and overtemperature protection (OTP) functions. These features make the system design easy, reliable, and safe with less external components.

For the AHB stage, the design supports zero-voltage switching (ZVS) with a wider operation range. This design employs TI's LMG2610, a half-bridge GaN device with level shift, bootstrap diode, and integrated gate drivers. The 170mΩ, 248mΩ GaN device with a QFN 7mm × 9mm package size helps developers shrink the PCB size.