SNVU773A March   2021  – April 2022 LM25148 , LM25148-Q1 , LM25149 , LM25149-Q1 , LM5148 , LM5148-Q1 , LM5149 , LM5149-Q1

 

  1.   Trademarks
  2. 1High Density EVM Description
    1. 1.1 Typical Applications
    2. 1.2 Features and Electrical Performance
  3. 2EVM Characteristics
  4. 3Application Circuit Diagram
  5. 4EVM Photo
  6. 5Test Setup and Procedure
    1. 5.1 EVM Connections
    2. 5.2 Test Equipment
    3. 5.3 Recommended Test Setup
      1. 5.3.1 Input Connections
      2. 5.3.2 Output Connections
    4. 5.4 Test Procedure
      1. 5.4.1 Line and Load Regulation, Efficiency
  7. 6Test Data and Performance Curves
    1. 6.1 Conversion Efficiency
    2. 6.2 Operating Waveforms
      1. 6.2.1 Switching
      2. 6.2.2 Load Transient Response
      3. 6.2.3 Line Transient Response
      4. 6.2.4 Start-Up and Shutdown With ENABLE ON and OFF
      5. 6.2.5 Start-Up and Shutdown with EN Tied to VIN
    3. 6.3 Bode Plot
    4. 6.4 CISPR 25 EMI Performance
    5. 6.5 Thermal Performance
  8. 7EVM Documentation
    1. 7.1 Schematic
    2. 7.2 Bill of Materials
    3. 7.3 PCB Layout
    4. 7.4 Component Drawings
  9. 8Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
        1. 8.2.1.1 PCB Layout Resources
        2. 8.2.1.2 Thermal Design Resources
  10. 9Revision History

6.4 CISPR 25 EMI Performance

Figure 6-14 presents the EMI performance of the LM25149-Q1 EVM at 12-V input with and without the EMI mitigation techniques enabled. Conducted emissions are measured over a frequency range of 150 kHz to 30 MHz using a 5-µH LISN according to the CISPR 25 low-frequency specification. CISPR 25 class 5 peak and average limit lines are denoted in red. The yellow and blue spectra are measured using peak and average detection, respectively.

Figure 6-14 CISPR 25 Class 5 Conducted Emissions Plot, 150 kHz to 30 MHz, VIN = 12 V, IOUT = 8 A Resistive Load, (a) No EMI Mitigation, (b) Active EMI and Spread-Spectrum Enabled