TIDUFC8 July   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Introduction
      2. 2.2.2 Basic Operation Principles and ZVS Requirements
    3. 2.3 Highlighted Products
      1. 2.3.1 UCC27288
      2. 2.3.2 UCC23513
      3. 2.3.3 TMS320F2800137
      4. 2.3.4 TLV9062
      5. 2.3.5 INA181
      6. 2.3.6 TPSM861252
      7. 2.3.7 AMC0311R
  9. 3System Design Theory
    1. 3.1 Design Theory
      1. 3.1.1 Resonant Tank Design
      2. 3.1.2 Full-Range ZVS Realization
      3. 3.1.3 Total Control Algorithm
      4. 3.1.4 Resonant Tank RMS Current Analysis
    2. 3.2 Hardware Design Theory
      1. 3.2.1 Resonant Capacitors
      2. 3.2.2 Power Stage
      3. 3.2.3 Voltage Sensing
      4. 3.2.4 Current Sensing
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Software Requirements
      1. 4.2.1 Simulation
    3. 4.3 Test Setup
    4. 4.4 Test Results
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
      3. 5.1.3 PCB Layout Recommendations
        1. 5.1.3.1 Layout Prints
    2. 5.2 Tools
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

3.1.3 Total Control Algorithm

The previous section analyzed that to make sure all switches implement ZVS, let θ = 2arctan(1/M); however, for this topology, this is not only necessary to provide soft switching to optimize efficiency, but also to control the charge and discharge current, that is, control power. This reflects the limitations of traditional single-phase-shift, single-degree-of-freedom control, which makes this impossible to control the current if the phase-shift angle is fixed.

This design has a second degree of freedom that can be controlled – the switching frequency – when the phase-shift angle is taken as a ZVS constraint. That is, the switching frequency can be introduced into the current closed loop to control the charge and discharge current. Figure 3-4 shows the total control block diagram.

The two degrees of freedom are calculated separately, the first is the phase-shift angle θ, which is calculated by sensing the input voltage and the output voltage to calculate the voltage gain M. The phase-shift angle is calculated by the formula (9) derived above, which is used to achieve ZVS.

Then is the switching frequency fs, fs is used to control the transferred power, which is generated by current loop. The charge/discharge current is sensed, and then the difference with the current reference value is made to generate an error signal, and then through a PI link, the PI output is used to calculate the switching frequency fs, which is used to control the power.

TIDA-010966 Total Control Block DiagramFigure 3-4 Total Control Block Diagram