SLVU192B February   2007  – January 2022 TPS40077

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Description
    2. 1.2 Applications
    3. 1.3 Features
  3. 2TPS40077EVM-001 Electrical Performance Specifications
  4. 3Schematic
    1. 3.1 Adjusting Output Voltage (R3 and R13)
    2. 3.2 Disable (J3)
    3. 3.3 Test Set Up
      1. 3.3.1 Equipment
        1. 3.3.1.1 Voltage Source
        2. 3.3.1.2 Meters
        3. 3.3.1.3 Loads
        4. 3.3.1.4 Oscilloscope
        5. 3.3.1.5 Recommended Wire Gauge
    4. 3.4 Equipment Setup
      1. 3.4.1 Procedure
      2. 3.4.2 Diagram
    5. 3.5 Start-Up/Shut Down Procedure
    6. 3.6 Control Loop Gain and Phase Measurement Procedure
    7. 3.7 Equipment Shutdown
  5. 4TPS40077EVM Typical Performance Data and Characteristic Curves
    1. 4.1 Efficiency
    2. 4.2 Line and Load Regulation
    3. 4.3 Output Ripple
    4. 4.4 Transient Response
    5. 4.5 Bode Plot
  6. 5EVM Assembly Drawings and Layout
  7. 6List of Materials
  8. 7Revision History

3.6 Control Loop Gain and Phase Measurement Procedure

  1. Connect a 1-kHz to 1-MHz isolation transformer to TP3 and TP6 as shown in Figure 3-4.
  2. Connect an .input-signal amplitude-measurement probe (channel A) to TP3 as shown in Figure 3-4
  3. Connect an output-signal amplitude measurement probe (channel B) to TP6 as shown in Figure 3-4.
  4. Connect the ground lead of channel A and channel B to TP8 as shown in Figure 3-4.
  5. Inject 25-mV or less signal across TP3 and TP6 through an isolation transformer.
  6. Sweep frequency from 1 kHz to 1 MHz with 10 Hz or lower post filter.
  7. Control-loop gain can be measured by GUID-4352BECE-8C97-47B5-BD7E-229F72C32B75-low.gif.
  8. Control-loop phase is measured by the phase difference between channel A and channel B.
  9. Disconnect an isolation transformer from TP3 and TP6 before making other measurements (signal injection into feedback can interfere with accuracy of other measurements).