TIDT222 April   2021

 

  1. 1Description
  2. 2Test Prerequisites
    1. 2.1 Voltage and Current Requirements
    2. 2.2 Required Equipment
    3. 2.3 Considerations
    4. 2.4 Dimensions
    5. 2.5 Test Setup
  3. 3Testing and Results
    1. 3.1 Efficiency and Loss Graphs
    2. 3.2 Efficiency Data
    3. 3.3 Thermal Images
    4. 3.4 Bode Plots
  4. 4Waveforms
    1. 4.1 Switching
    2. 4.2 Output Voltage Ripple
    3. 4.3 Load Transients
    4. 4.4 Start-up Sequence

3.4 Bode Plots

The following plot shows the loop gain and phase margin of the converter when loaded to 1.2 V at 40 A.

  • VIN = 12 V, Bandwidth = 23 kHz , Phase Margin = 68 degrees

The loop is set by pinstrap resistors using 550 kHz and compensation code 18 as the fastest loop allowed among the 32 pinstrap selections:

GUID-20210105-CA0I-F8VS-TRZR-G1JRLBW7GMJM-low.jpgFigure 3-7 Bode Plot, Pinstrap Resistors

Loop set up using Nonvolatile Memory (NVM) programming which allows for many more than 32 compensation selections.

  • Code11408458C2 used: 36-kHz bandwidth and 51 degrees of phase margin
GUID-20210105-CA0I-6FHK-0HM8-DK7LFWNXGSWB-low.jpgFigure 3-8 Bode Plot, NVM