TIDUF18A October   2022  – February 2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1 CLLLC System Description
    1. 1.1 Key System Specifications
  8. 2 CLLLC System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations and System Design Theory
      1. 2.2.1 Tank Design
        1. 2.2.1.1 Voltage Gain
        2. 2.2.1.2 Transformer Gain Ratio Design (NCLLLC)
        3. 2.2.1.3 Magnetizing Inductance Selection (Lm)
        4. 2.2.1.4 Resonant Inductor and Capacitor Selection (Lrp and Crp)
      2. 2.2.2 Current and Voltage Sensing
        1. 2.2.2.1 VPRIM Voltage Sensing
        2. 2.2.2.2 VSEC Voltage Sensing
        3. 2.2.2.3 ISEC Current Sensing
        4. 2.2.2.4 ISEC TANK and IPRIM TANK
        5. 2.2.2.5 IPRIM Current Sensing
        6. 2.2.2.6 Protection (CMPSS and X-Bar)
      3. 2.2.3 PWM Modulation
  9. 3 Totem Pole PFC System Description
    1. 3.1 Benefits of Totem-Pole Bridgeless PFC
    2. 3.2 Totem-Pole Bridgeless PFC Operation
    3. 3.3 Key System Specifications
    4. 3.4 System Overview
      1. 3.4.1 Block Diagram
    5. 3.5 System Design Theory
      1. 3.5.1 PWM
      2. 3.5.2 Current Loop Model
      3. 3.5.3 DC Bus Regulation Loop
      4. 3.5.4 Soft Start Around Zero-Crossing for Eliminating or Reducing Current Spike
      5. 3.5.5 Current Calculation
      6. 3.5.6 Inductor Calculation
      7. 3.5.7 Output Capacitor Calculation
      8. 3.5.8 Current and Voltage Sense
  10. 4 Highlighted Products
    1. 4.1 C2000 MCU TMS320F28003x
    2. 4.2 LMG352xR30-Q1
    3. 4.3 UCC21222-Q1
    4. 4.4 AMC3330-Q1
    5. 4.5 AMC3302-Q1
  11. 5 Hardware, Software, Testing Requirements, and Test Results
    1. 5.1 Required Hardware and Software
      1. 5.1.1 Hardware Settings
        1. 5.1.1.1 Control Card Settings
      2. 5.1.2 Software
        1. 5.1.2.1 Opening the Project Inside Code Composer Studio
        2. 5.1.2.2 Project Structure
    2. 5.2 Testing and Results
      1. 5.2.1 Test Setup (Initial)
      2. 5.2.2 CLLLC Test Procedure
        1. 5.2.2.1 Lab 1. Primary to Secondary Power Flow, Open Loop Check PWM Driver
        2. 5.2.2.2 Lab 2. Primary to Secondary Power Flow, Open Loop CheckPWM Driver and ADC with Protection, Resistive Load Connected on Secondary
          1. 5.2.2.2.1 Setting Software Options for Lab 2
          2. 5.2.2.2.2 Building and Loading the Project and Setting up Debug Environment
          3. 5.2.2.2.3 Using Real-time Emulation
          4. 5.2.2.2.4 Running the Code
          5. 5.2.2.2.5 Measure SFRA Plant for Voltage Loop
          6. 5.2.2.2.6 Verify Active Synchronous Rectification
          7. 5.2.2.2.7 Measure SFRA Plant for Current Loop
        3. 5.2.2.3 Lab 3. Primary to Secondary Power Flow, Closed Voltage Loop Check, With Resistive Load Connected on Secondary
          1. 5.2.2.3.1 Setting Software Options for Lab 3
          2. 5.2.2.3.2 Building and Loading the Project and Setting up Debug Environment
          3. 5.2.2.3.3 Running the Code
          4. 5.2.2.3.4 Measure SFRA for Closed Voltage Loop
        4. 5.2.2.4 Lab 4. Primary to Secondary Power Flow, Closed Current Loop Check, With Resistive Load Connected on Secondary
          1. 5.2.2.4.1 Setting Software Options for Lab 4
          2. 5.2.2.4.2 Building and Loading the Project and Setting up Debug
          3. 5.2.2.4.3 Running the Code
          4. 5.2.2.4.4 Measure SFRA for Closed Current Loop
        5. 5.2.2.5 Lab 5. Primary to Secondary Power Flow, Closed Current Loop Check, With Resistive Load Connected on Secondary in Parallel to a Voltage Source to Emulate a Battery Connection on Secondary Side
          1. 5.2.2.5.1 Setting Software Options for Lab 5
          2. 5.2.2.5.2 Designing Current Loop Compensator
          3. 5.2.2.5.3 Building and Loading the Project and Setting up Debug
          4. 5.2.2.5.4 Running the Code
          5. 5.2.2.5.5 Measure SFRA for Closed Current Loop in Battery Emulated Mode
      3. 5.2.3 TTPLPFC Test procedure
        1. 5.2.3.1 Lab 1: Open Loop, DC
          1. 5.2.3.1.1 Setting Software Options for BUILD 1
          2. 5.2.3.1.2 Building and Loading Project
          3. 5.2.3.1.3 Setup Debug Environment Windows
          4. 5.2.3.1.4 Using Real-Time Emulation
          5. 5.2.3.1.5 Running Code
        2. 5.2.3.2 Lab 2: Closed Current Loop DC
          1. 5.2.3.2.1 Setting Software Options for BUILD 2
          2. 5.2.3.2.2 Designing Current Loop Compensator
          3. 5.2.3.2.3 Building and Loading Project and Setting Up Debug
          4. 5.2.3.2.4 Running Code
        3. 5.2.3.3 Lab 3: Closed Current Loop, AC
          1. 5.2.3.3.1 Setting Software Options for Lab 3
          2. 5.2.3.3.2 Building and Loading Project and Setting Up Debug
          3. 5.2.3.3.3 Running Code
        4. 5.2.3.4 Lab 4: Closed Voltage and Current Loop
          1. 5.2.3.4.1 Setting Software Options for BUILD 4
          2. 5.2.3.4.2 Building and Loading Project and Setting up Debug
          3. 5.2.3.4.3 Running Code
      4. 5.2.4 Test Results
        1. 5.2.4.1 Efficiency
        2. 5.2.4.2 System Performance
        3. 5.2.4.3 Bode Plots
        4. 5.2.4.4 Efficiency and Regulation Data
        5. 5.2.4.5 Thermal Data
        6. 5.2.4.6 PFC Waveforms
        7. 5.2.4.7 CLLLC Waveforms
  12. 6 Design Files
    1. 6.1 Schematics
    2. 6.2 Bill of Materials
    3. 6.3 Altium Project
    4. 6.4 Gerber Files
  13. 7 Software Files
  14. 8 Related Documentation
    1. 8.1 Trademarks
  15. 9 Terminology
  16. 10About the Author
  17. 11Revision History

4.1 C2000 MCU TMS320F28003x

C2000™ 32-bit microcontrollers are optimized for processing, sensing, and actuation to improve closed-loop performance in real-time control applications such as industrial motor drives; solar inverters and digital power; electrical vehicles and transportation; motor control; and sensing and signal processing.

The TMS320F28003x (F28003x) is a powerful 32-bit floating-point microcontroller unit (MCU) that lets designers incorporate crucial control peripherals, differentiated analog, and nonvolatile memory on a single device.

The CLA allows significant offloading of common tasks from the main C28x CPU. The CLA is an independent 32-bit floating-point math accelerator that executes in parallel with the CPU. Additionally, the CLA has its own dedicated memory resources and it can directly access the key peripherals that are required in a typical control system. Support of a subset of ANSI C is standard, as are key features like hardware breakpoints and hardware task-switching.

High-performance analog blocks are integrated on the F28003x MCU to further enable system consolidation. Three separate 12-bit ADCs provide precise and efficient management of multiple analog signals, which ultimately boosts system throughput. Four analog comparator modules provide continuous monitoring of input voltage levels for trip conditions.

The TMS320C2000™ devices contain industry-leading control peripherals with frequency-independent Enhanced Pulse Width Modulator/High-Resolution Pulse Width Modulator (ePWM/HRPWM) and Enhanced Capture (eCAP) module allow for a best-in-class level of control to the system. The built-in Sigma-Delta Filter Module (SDFM) allows for seamless integration of an oversampling sigma-delta modulator across an isolation barrier.

Connectivity is supported through various industry-standard communication ports [such as Serial Peripheral Interface (SPI); Serial Communication Interface (SCI); Inter-integrated Circuit (I2C); and Controller Area Network (CAN)] and offers multiple multiplexing options for optimal signal placement in a variety of applications. New to the C2000™ platform is the fully compliant Power-Management Bus (PMBus). Additionally, in an industry first, the Fast Serial Interface (FSI) enables high-speed, robust communication to complement the rich set of peripherals that are embedded in the device.

A specially enabled device variant, TMS320F28003xC, allows access to the Configurable Logic Block (CLB) for additional interfacing features. See the Device Comparison table in the TMS320F28003x microcontrollers data manual for more information.

The Embedded Real-Time Analysis and Diagnostic (ERAD) module enhances the debug and system analysis capabilities of the device by providing additional hardware breakpoints and counters for profiling.

Following is the subset of features of the C2000 MCU that are highlighted on this design to enable control of high-frequency CLLLC topology:

  1. High-resolution PWM: With picosecond resolutions possible, the ePWM module on the C2000 MCU can generate high-frequency PWM with accuracy. With the Type-4 PWM high-resolution period control, high-resolution duty control, high-resolution dead-band control, along with high-resolution phase shift control, is possible. This enables generation of balanced pulses for the resonant tank excitation and is an enabling feature for high-frequency power converters.
  2. Comparator Subsystem (CMPSS) with ePWM for active synchronous rectification: Active synchronous rectification enables higher efficiency and for high-frequency resonant converters that operate both below and above the resonant point, it is a necessary feature for the topology. The C2000 MCUs' integrated CMPSS enables generation of the active synchronous rectification pulses by using the integrated comparators and the integrated Digital-to-Analog Converters (DACs). (See Section 2.2.2.4.)
  3. Blanking window: Due to noise, which is unavoidable in switching converters, the blanking window feature is used to suppress the CMPSS output during noisy switching events. This blanking window is provided by the ePWM time base and can be applied at different times during the PWM cycle. (See Section 2.2.3.)
  4. X-Bar: Multiple trip sources are possible in a power converter. The X-bar enables combining different trip actions from either different CMPSS or from GPIO to generate trip behavior desired in the ePWM without need of external logic.
  5. Control Law Accelerator (CLA) enables integration of control of multiple topologies on a single controller. The software provided with this design provides the option to run the control loop on the CLA or the C28x.
  6. Global Link feature in PWM module enables update to multiple PWMs through a single write, which reduces the CPU burden and enables higher-frequency converters to be controlled easily.