SLVUBW7 May   2020

 

  1.   TPS7H4001QEVM-CVAL Evaluation Module User's Guide
    1.     Trademarks
    2. 1 TPS7H4001QEVM-CVAL Overview
      1. 1.1 Features
      2. 1.2 Applications
    3. 2 TPS7H4001QEVM-CVAL Default Configuration
    4. 3 TPS7H4001QEVM-CVAL Initial Setup
    5. 4 TPS7H4001QEVM-CVAL Testing
      1. 4.1 Output Voltage Regulation
      2. 4.2 Quadrature Phases
      3. 4.3 Output Voltage Ripple
      4. 4.4 Soft Startup
      5. 4.5 Transient Response to Positive/Negative Load Step (27 A to 67 A to 27 A)
      6. 4.6 Loop Frequency Response
      7. 4.7 Efficiency
      8. 4.8 Current Limiting
      9. 4.9 Current Sharing
    6. 5 TPS7H4001QEVM-CVAL EVM Schematic
    7. 6 TPS7H4001QEVM-CVAL Bill of Materials (BOM)
    8. 7 Board Layout
    9. 8 Appendix A

4.6 Loop Frequency Response

Measuring the frequency response of the feedback loop requires a unique test setup as well as physical changes to the EVM. 0-Ω resistor jumper R18, to the right of TP16 (BODE) test point and circled in yellow in the graphic below, must be lifted in order to break the loop. Both test points TP16 (BODE) and TP15 (VOUT1) will be used for connections to the Bode100 instruments.

TPS7H4001QEVM-CVAL 009_LOOP1.pngFigure 9. EVM Modification to Measure Frequency Response

The test setup which includes several connections to Picotest Bode100 test instruments is shown in Figure 10 with measurement results shown in Figure 11.

TPS7H4001QEVM-CVAL 010_LOOP3.jpgFigure 10. Frequency Response Measurement Setup
TPS7H4001QEVM-CVAL LoopResponse.pngFigure 11. Loop Frequency Response (Rcomp=2kohms, Ccomp=33nF, CHF=330pF)