3.1 C2000 Digital Power Supply Workshop
NOTE: This workshop is obsolete and the EVM is discontinued. The workshop materials on this page are no longer being updated or maintained, and are provided “as is”. However, the workshop materials can still be very useful and is provided here for reference. The CCS projects which are used with the lab exercise source files will need to be recreated for use with later versions of the software.
To design power supplies, a good understanding of power electronics and control is required. Traditionally, microcontrollers have been restricted to only performing supervisory and/or communications tasks in these systems. With the availability of high performing microcontrollers, it is possible to use them for closing control loops in addition to handling the traditional microcontroller functions. These systems can implement advanced control strategies to optimally control the power stage under different conditions and also provide system-level intelligence. This necessitates the power supply engineer to gain a good understanding of digital control as applied to power supplies. This hands-on 1-day DPS workshop is designed to help both analog and digital engineers get familiar with basic concepts and key care-abouts of digital control as applied to power supply design. This workshop uses the C2000 DPS Workshop EVM board with a TMS320F28035 controller.
This workshop is divided into 5 chapters. Each chapter is followed by a corresponding lab. The workshop starts with an introduction to C2000 microcontrollers and the development environment in the first chapter. This is followed by a discussion on some basic digital power supply concepts and open loop power stage excitation. More advanced topics like peak current mode control (PCMC), closing of control loops and using control law accelerator (CLA) are discussed in the following chapters. Each lab builds on the topics discussed in the accompanying chapter.
This workshop material enables the user to understand the challenges in designing a digital power supply. It also shows how C2000 MCUs can interface to and control different power stages used in these applications. C2000 DPS software libraries are used in the workshop labs. These enable the customers to shorten their product development cycle.
- C28x Controller Overview
- Lab1: Introduction to Code Composer Studio
Open loop operation
- Digital power library software structure and user interface
- Generating pulse width modulated (PWM) waveforms
- Lab2: Open loop control
Implementing Peak Current Mode Control (PCMC)
- Introduction to PCMC scheme
- PCMC challenges with digital implementations
- Lab 3: Open voltage loop PCMC
Closing the loop
- Analog to digital converter (ADC)
- Closed voltage loop block diagram (VMC and PCMC)
- Tuning a control loop
- Lab 4: Closed loop operation with VMC and PCMC
Control Law Accelerator (CLA)
- Introduction to CLA
- Sharing data with CPU
- Lab 5: Closed loop operation with PCMC on CLA and VMC on CPU
Requirements for running the DPS workshop lab exercises:
- C2000 DPS Workshop EVM (TMDSC2KWRKSHPKIT) - - DISCONTINUED
- Code Composer Studio v5 - is the version of the integrated development environment which was used for software development with this workshop.
- Download software package (includes workshop manual and lab files): Workshop Application Code (.zip file)
Unzip in a convenient location on the computer. The zip package is a standalone package with all the necessary files and manual needed to run the workshop. It is recommended to unzip the file under C:\TI, the unzipped folder will look as follows:
->device support (contains header files and other supporting files needed to program the controller)
->libs (contains libraries such as Solar Library, Digital Power Library, IQMath Library, SGEN Library)
->~Docs (DPS Workshop Hardware Guide, DPS Workshop Manual, and Board Schematics)
->Lab1 (Files for Lab 1)
->Lab2 (CCS Project for Lab2)
->Lab3 (CCS Project for Lab3)
->Lab4 (CCS Project for Lab4)
->Lab5 (CCS Project for Lab5)
The presentation slides for the different modules are included in the 'DPS Workshop Manual' under the '~Docs' folder.