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

8.2 Control Loop Gain and Phase Measurement Procedure

The TPS51113-EVM contains a 20-Ω series resistor in the feedback loop for loop response analysis.

  1. Set up the EVM as described in Section 8.1 and Figure 7-2.
  2. Connect the isolation transformer to test points marked TP4 and TP3.
  3. Connect an input signal amplitude measurement probe (channel A) to TP4.
  4. Connect an output signal amplitude measurement probe (channel B) to TP3. Connect the ground lead of channel A and channel B to TP9 and TP10.
  5. Inject around 40-mV or less signal through the isolation transformer.
  6. Sweep the frequency from 100 Hz to 1 MHz with a 10-Hz or lower post filter. The control loop gain and phase margin can be measured.
  7. Disconnect the isolation transformer from the bode plot test points before making other measurements (Signal injection into feedback may interfere with accuracy of other measurements).