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

4.1.4 Oscilloscope

A Digital or Analog Oscilloscope can be used to measure the ripple voltage on VOUT1 or VOUT2. The oscilloscope should be set for the following for taking output ripple measurements:

  • 1-MΩ impedance
  • 20-MHz Bandwidth
  • AC coupling
  • 1-μs/division horizontal resolution
  • 10-mV/division vertical resolution
TP3 and TP4 or TP18 and TP19 can be used to measure the output ripple voltages by placing the oscilloscope probe tip through TP3 or TP18 and holding the ground barrel to TP4 or TP19 as shown in Figure 4-2. For a hands free approach, the loop in TP4 or TP19 can be cut and opened to cradle the probe barrel. Using a leaded ground connection can induce additional noise due to the large ground loop area.