TIDUFD2 May   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Terminology
    2. 1.2 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Input Capacitors Selection
      2. 2.2.2 DC Side
      3. 2.2.3 AC Side
    3. 2.3 Highlighted Products
      1. 2.3.1 TMDSCNCD28P55X - controlCARD Evaluation Module
        1. 2.3.1.1 Hardware Features
        2. 2.3.1.2 Software Features
      2. 2.3.2 LMG2100R026 - 100V, 53A GaN Half-Bridge Power Stage
      3. 2.3.3 LMG365xR035 - 650V 35mΩ GaN FET With Integrated Driver and Protection
      4. 2.3.4 TMCS1123 - Precision 250kHz Hall-Effect Current Sensor With Reinforced Isolation
      5. 2.3.5 TMCS1133 - Precision 1MHz Hall-Effect Current Sensor With Reinforced Isolation
      6. 2.3.6 INA185 - 26V, 350kHz, Bidirectional, High-Precision Current Sense Amplifier
      7. 2.3.7 LM5164 – 100V Input, 1A Synchronous Buck DC-DC Converter With Ultra-Low IQ
      8. 2.3.8 ISO6762 – General-Purpose Six-Channel Reinforced Digital Isolators With Robust EMC
  9. 3System Design Theory
    1. 3.1 Isolation for Solar Inverters
    2. 3.2 Topology Overview
    3. 3.3 Control Theory
      1. 3.3.1 Single and Extended Phase Shift Modulation Technique
      2. 3.3.2 Zero Voltage Switching and Circulating Current
      3. 3.3.3 Optimized Control Method
      4. 3.3.4 Dead-Time Compensation
      5. 3.3.5 Frequency Modulation
      6. 3.3.6 Controller Block Diagram
    4. 3.4 MPPT and Input Voltage Ripple
  10. 4Hardware, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Test Setup
      1. 4.2.1 Board Check
      2. 4.2.2 DC-DC Tests
      3. 4.2.3 DC-AC Tests
    3. 4.3 Test Results
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

2.2.3 AC Side

The AC side has a half-bridge cycloconverter developed with two AC switches. Figure 2-4 shows the AC switch schematic. The switch is made from two back-to-back LMG3650R035 devices connected in a common source configuration. This configuration allows two power stages to share a common bias power supply and a digital isolator.

TIDA-010954 High-Voltage AC Switch Schematic Figure 2-4 High-Voltage AC Switch Schematic

The isolated power supply is formed by generating a 5V output from the isolated UCC33421-Q1 module. This 5V voltage is then utilized to supply a digital isolator, and also serves as the input to a boost converter, specifically the TLV61046 device.

The TLV61046 boost converter subsequently generates 10V for powering the gate driver stage of the LMG3650R035 switching power stage

The AC side incorporates a half-bridge cycloconverter based on two AC switches. Figure 2-5 illustrates the AC switch schematic, which comprises two back-to-back connected LMG3650R035 devices in common source configuration.

TIDA-010954 AC Filtering and Measurement Figure 2-5 AC Filtering and Measurement

This particular configuration enables two power stages to share a common bias power supply and digital isolator, simplifying the circuit arrangement and improving overall efficiency.