TIDT382 February   2024

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Considerations
    3. 1.3 Dimensions
  6. 2Testing and Results
    1. 2.1 Efficiency Graphs
      1. 2.1.1 LM25180-Q1 Efficiency Graph
      2. 2.1.2 SN6507-Q1 Efficiency Graph
      3. 2.1.3 UCC14130-Q1 Efficiency Graph
      4. 2.1.4 UCC25800-Q1 Efficiency Graph
      5. 2.1.5 Efficiency Comparison
    2. 2.2 Efficiency Data
      1. 2.2.1 LM25180-Q1 Efficiency Data
      2. 2.2.2 SN6507-Q1 Efficiency Data
      3. 2.2.3 UCC14130-Q1 Efficiency Data
      4. 2.2.4 UCC25800-Q1 Efficiency Data
    3. 2.3 Load Regulation
      1. 2.3.1 LM25180-Q1 Load Regulation
      2. 2.3.2 SN6507-Q1 Load Regulation
      3. 2.3.3 UCC14130-Q1 Load Regulation
      4. 2.3.4 UCC25800-Q1 Load Regulation
      5. 2.3.5 Load Regulation Comparison
    4. 2.4 Thermal Images
      1. 2.4.1 LM25180-Q1 Thermal Image
      2. 2.4.2 SN6507-Q1 Thermal Image
      3. 2.4.3 UCC14130-Q1 Thermal Image
      4. 2.4.4 UCC25800-Q1 Thermal Image
    5. 2.5 Common-Mode Current (CMI)
      1. 2.5.1 LM25180-Q1 CMI
      2. 2.5.2 SN6507-Q1 CMI
      3. 2.5.3 UCC14130-Q1 CMI
      4. 2.5.4 UCC25800-Q1 CMI
      5. 2.5.5 Common-Mode Current Comparison
  7. 3Waveforms
    1. 3.1 Switching
      1. 3.1.1 LM25180-Q1 Switching
      2. 3.1.2 SN6507-Q1 Switching
      3. 3.1.3 UCC25800-Q1 Switching
    2. 3.2 Output Voltage Ripple
      1. 3.2.1 LM25180-Q1 Output Voltage Ripple
      2. 3.2.2 SN6507-Q1 Output Voltage Ripple
      3. 3.2.3 UCC14130-Q1 Output Voltage Ripple
      4. 3.2.4 UCC25800-Q1 Output Voltage Ripple
      5. 3.2.5 Output Voltage Ripple Comparison
    3. 3.3 Input Voltage Ripple
      1. 3.3.1 LM25180-Q1 Input Voltage Ripple
      2. 3.3.2 SN6507-Q1 Input Voltage Ripple
      3. 3.3.3 UCC14130-Q1 Input Voltage Ripple
      4. 3.3.4 UCC25800-Q1 Input Voltage Ripple
      5. 3.3.5 Input Voltage Ripple Comparison
    4. 3.4 Load Transients
      1. 3.4.1 LM25180-Q1 Load Transients
      2. 3.4.2 SN6507-Q1 Load Transients
      3. 3.4.3 UCC14130-Q1 Load Transients
      4. 3.4.4 UCC25800-Q1 Load Transients
    5. 3.5 Start-Up Sequence
      1. 3.5.1 LM25180-Q1 Start-Up Sequence
      2. 3.5.2 SN6507 Q1 Start Up Sequence
      3. 3.5.3 UCC14130-Q1 Start-Up Sequence
      4. 3.5.4 UCC25800-Q1 Start-Up Sequence
    6. 3.6 Shutdown Sequence
      1. 3.6.1 LM25180-Q1 Shutdown Sequence
      2. 3.6.2 SN6507-Q1 Shutdown Sequence
      3. 3.6.3 UCC14130-Q1 Shutdown Sequence
      4. 3.6.4 UCC25800-Q1 Shutdown Sequence
    7. 3.7 Undervoltage Protection
      1. 3.7.1 LM25180-Q1 Undervoltage Protection
      2. 3.7.2 SN6507-Q1 Undervoltage Protection
      3. 3.7.3 UCC14130-Q1 Undervoltage Protection
      4. 3.7.4 UCC25800-Q1 Undervoltage Protection
  8. 4Summary
  9. 5References

2.5 Common-Mode Current (CMI)

Common-Mode Current (CMI) tests were done while running both isolated bias power supply converter circuits at 15V output and switching the GaN half-bridge at 400V. Common-mode current flows from the high-voltage side to the low-voltage side through the parasitic capacitance across the isolation barrier. Common mode current is generated due to switching of the high- and low-side GaN half bridge switches at a high slew rate. During the measurements, high- and low-voltage grounds were shorted using a wire (shown in Figure 2-15) to minimize the length of the common-mode current loop from high-voltage side to low-voltage side. This can be considered as a worst-case scenario for common-mode current and results in the highest possible common-mode current through the isolation barrier. CMI current measurements are taken on two different high slew rate values: 40V/ns and 100V/ns. CMI measurements are taken while bypassing the input filter. Using a potentiometer at the RDRV pin of the LMG3525R030Q, the slew rate can be varied with reference to the selected resistor value. Figure 2-15 shows the CMI test setup.

GUID-20240116-SS0I-XMLJ-9MSL-0B31QFS7GPXJ-low.pngFigure 2-15 Common-Mode Current (CMI) Test Setup