Introduction

This reference design is useful for implementing a digitally peak current mode controlled (PCMC) phase shifted full bridge (PSFB) DC-DC converter which converts a 400V DC input to a regulated 12V DC output and vice-versa. Although the design is capable of performing bi-directional power conversion, the scope of this application note is limited to illustrate only high voltage to low voltage conversion i.e step down operation. Novel PCMC waveform generation based on type-5 PWM and internal slope compensation, and simple PCMC implementation are the highlights of this design.

Below images show the block diagram of the converter and the actual hardware respectively:-

Block Diagram of PSFB DC/DC converter of TIDM-02009 design

Hardware image of PSFB DC/DC converter of TIDM-02009 design

Features Supported

This version of reference design supports:

Example has to be executed from R5F Core0 to have real time debug capability
Open loop testing
Closed current open voltage loop testing
Closed current closed voltage loop testing
Testing with synchronous rectification(SR) mode enabled

Features Not Supported

Testing has been done upto 250W. Hardware has not been tested upto rated capacity yet.

Benchmark Results

A benchmark on R5F core has been conducted to observe the following results when running the following functions:

Function	Clock Cycles with Level-s Compiler Optimization	Clock Cycles without Compiler Optimization	CPU Loading with Level-s Compiler Optimization	CPU Loading without Compiler Optimization
ISR2- PCMC control	532	1582	13.3%	39.55%

Provided Examples

The following example has been provided to demonstrate this reference design:

TIDM-02009 DC/DC Converter Test

Useful Links

Useful links for the application to run are provided below:

Design guide of TIDM-02009 can be found in TIDM-02009 Design Guide
Application Note on TIDM-02009 PSFB Converter implementation using AM263x MCU can be found in TIDM-02009 DC/DC Converter Application Note