SLVU356A January   2010  – October 2021 TPS54290 , TPS54291

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Description
    2. 1.2 Applications
    3. 1.3 Features
  3. 2TPS54291EVM-431 Electrical Performance Specifications
  4. 3Schematic
    1. 3.1 Enable Jumpers (JP1 and JP2)
    2. 3.2 Error Amplifier Outputs
    3. 3.3 Test Point Descriptions
      1. 3.3.1 Input Voltage Monitoring (TP1 and TP2)
      2. 3.3.2 Channel 1 Output Voltage Monitoring (TP3 and TP4)
      3. 3.3.3 Channel 1 Loop Analysis (TP5, TP6, TP7, and TP8)
      4. 3.3.4 Channel 1 Switching Waveforms (TP9 and TP10)
      5. 3.3.5 TPS54291 IC Ground (TP11)
      6. 3.3.6 Channel 2 Switching Waveforms (TP12 and TP13)
      7. 3.3.7 Channel 2 Loop Analysis (TP14, TP15, TP16, and TP17)
      8. 3.3.8 Output Voltage Monitoring (TP18 and TP19)
  5. 4Test Setup
    1. 4.1 Equipment
      1. 4.1.1 Voltage Source (VIN)
      2. 4.1.2 Meters
      3. 4.1.3 Loads
      4. 4.1.4 Oscilloscope
      5. 4.1.5 Recommended Wire Gauge
      6. 4.1.6 Other
    2. 4.2 Equipment Setup
      1. 4.2.1 Procedure
      2. 4.2.2 Diagram
    3. 4.3 Start-Up/Shutdown Procedure
    4. 4.4 Output Ripple Voltage Measurement Procedure
    5. 4.5 Control Loop Gain and Phase Measurement Procedure
    6. 4.6 Equipment Shutdown
  6. 5TPS54291EVM-431 Typical Performance Data and Characteristic Curves
    1. 5.1 Efficiency
    2. 5.2 Line and Load Regulation
    3. 5.3 Switch Node and Output Ripple Voltage
  7. 6EVM Assembly Drawings and Layout
  8. 7List of Materials
  9. 8Revision History

3.3.3 Channel 1 Loop Analysis (TP5, TP6, TP7, and TP8)

The TPS54291EVM-431 contains a 51-Ω series resistor (R1) in the feedback loop to allow for matched impedance signal injection into the feedback for loop response analysis. An isolation transformer should be used to apply a small (30 mV or less) signal across R1 through TP6 and TP8. By monitoring the AC injection level at TP8 and the returned AC level at TP6, the power supply loop response can be determined.