TIDUFC9 May   2025

 

  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 Codec Design
      2. 2.2.2 Class-D Amplifier
        1. 2.2.2.1 Audio Filter Design
      3. 2.2.3 Power Design
      4. 2.2.4 EMC, EMI Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 TAC5312-Q1
      2. 2.3.2 TAS5441-Q1
      3. 2.3.3 LMR43620-Q1
      4. 2.3.4 TPS7A52-Q1
      5. 2.3.5 TPD2E007
  9. 3Hardware, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 Board Connection
      2. 3.1.2 Configuring the Board
    2. 3.2 Software Requirements
      1. 3.2.1 Firmware for Bench Tests
    3. 3.3 Test Setup
    4. 3.4 Test Results
      1. 3.4.1 Audio Performance
      2. 3.4.2 Power Tests
      3. 3.4.3 EMI, EMC Test Results
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 Bill of Materials
      3. 4.1.3 PCB Layout Recommendations
        1. 4.1.3.1 Layout Prints
      4. 4.1.4 Altium Project
      5. 4.1.5 Gerber Files
      6. 4.1.6 Assembly Drawings
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  11. 5About the Author

2.2.4 EMC, EMI Design Considerations

The layout must be designed with EMC considerations. See Section 4.1.3 for more information. The LMR43620-Q1 switching frequency can be adjusted from 200kHz to 2.2MHz and in this design the switching frequency is set to 2.2MHz reduce EMI and avoid AM band interference. Additionally, the TAS5441-Q1 switching frequency can be programmed to be either 400kHz or 500kHz. Changing the switching frequency is useful to shift where the emissions occur. If multiple devices in the system operate at the same frequency, then it is more difficult to pass the radiated emissions limits.