SLUUCU5 June   2024 TPS544C27

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
      1. 1.1.1 Before You Begin
    2. 1.2 Electrical Performance Specifications
    3. 1.3 Device Information
  8. 2Hardware
    1. 2.1 Test Equipment
      1. 2.1.1 Voltage Source
      2. 2.1.2 Oscilloscope
      3. 2.1.3 Multimeters
      4. 2.1.4 Output Load
      5. 2.1.5 Fan
      6. 2.1.6 USB-to-GPIO Interface Adapter:
      7. 2.1.7 Recommended Wire Gauge
    2. 2.2 List of Test Points, Jumpers, and Connectors
    3. 2.3 Efficiency Measurement Test Points
    4. 2.4 Control Loop Gain and Phase Measurement
    5. 2.5 External 5V bias to enhance efficiency
    6. 2.6 Input Current Measurement
  9. 3Software
    1. 3.1 Opening the PMBus Fusion GUI
    2. 3.2 Monitor Page
    3. 3.3 Status Page
  10. 4Performance Data and Typical Characteristics Curves
  11. 5Hardware Design Files
    1. 5.1 Schematics
    2. 5.2 PCB Layout
    3. 5.3 BOM
  12. 6Trademarks

2.4 Control Loop Gain and Phase Measurement

The TPS544C27EVM includes a R7 10Ω series resistor in the feedback loop for VOUT. The resistor is accessible at the test points TP14 (BODE_CHA) and TP8 (VOUT/BODE_CHB) for loop response analysis. These test points must be used during loop response measurements as the perturbation injecting points for the loop . See the description in Table 3-5.

Table 2-5 List of Test Points for Loop Response Measurements
Test Point Node Name Description Comment
TP14 BODE_CHA Input to feedback divider of VOUT The amplitude of the perturbation at this node must be limited to less than 30mV
TP8 VOUT_BODE_CHB Resulting output of VOUT Bode can be measured by a network analyzer with a CHB/CHA configuration

Measure the loop response with the following procedure:

  1. Set up the EVM as described in Section 2.
  2. For VOUT, connect the isolation transformer of the network analyzer from TP14 to TP8.
  3. Connect the input signal measurement probe to TP14. Connect the output signal measurement probe to TP8.
  4. Connect the ground leads of both probe channels to TP16 (PGND_REG).
  5. On the network analyzer, measure the Bode as TP14/TP8 (In/Out).