SLUU359A April   2009  – February 2022 TPS51113

 

  1.   Trademarks
  2. 1 Introduction
  3. 2 Description
  4. 3 Typical Applications
  5. 4 Features
  6. 5 Electrical Performance Specifications
  7. 6 Schematic
  8. 7 Test Setup
    1. 7.1 Test Equipment
      1. 7.1.1 Voltage Source
      2. 7.1.2 Multimeters
      3. 7.1.3 Output Load
      4. 7.1.4 Oscilloscope
      5. 7.1.5 Fan
      6. 7.1.6 Recommended Wire Gauge
    2. 7.2 Recommended Test Setup
      1. 7.2.1 Input Connections
      2. 7.2.2 Output Connections
      3. 7.2.3 Other Connections
  9. 8 Test Procedure
    1. 8.1 Line/Load Regulation and Efficiency Measurement Procedure
    2. 8.2 Control Loop Gain and Phase Measurement Procedure
    3. 8.3 Test Points
    4. 8.4 Equipment Shutown Procedure
  10. 9 Performance Data and Typical Characteristic Curves
  11. 10EVM Assembly Drawing and PCB Layout
  12. 11List of Materials
  13. 12References
  14. 13Revision History

7.1.4 Oscilloscope

A digital or analog oscilloscope can be used to measure the output ripple. The oscilloscope should be set for the following:

  • 1-MΩ impedance
  • 20-MHz bandwidth
  • AC coupling
  • 2-μs/division horizontal resolution
  • 50-mV/division vertical resolution

Test points TP6 and TP8 can be used to measure the output ripple voltage. Place the oscilloscope probe tip through TP6 and rest the ground barrel on TP8 as shown in Figure 7-1. Using a leaded ground connection may induce additional noise due to the large ground loop.

GUID-4CDCA56B-B654-40DD-8567-F1E573AC8CC7-low.gifFigure 7-1 Tip and Barrel Measurement for VOUT Ripple