SDAA184 June 2026 TMS320F28P550SG , TMS320F28P550SJ , TMS320F28P559SG-Q1 , TMS320F28P559SJ-Q1
This document provides the software documentation for a digitally controlled Asymmetrical Half Bridge (AHB) converter, a Flyback-derived resonant topology designed for high-efficiency and wide-output power conversion. The firmware implements zero-voltage switching (ZVS) control using a fast PWM on-time calculation and adaptive zero-voltage detection (ZVD) technique to maintain boundary ZVS across varying input and load conditions. It also includes programmable ZCD count control, adaptive soft-start, and inductance compensation algorithms to ensure stable performance under production variations.
The software has been validated on a 280 W AHB hardware prototype, achieving a peak efficiency of 97.8% at 28 V / 9A. This documentation details the software structure, control algorithms, and implementation methods that enable robust digital control of AHB converters, targeting high-power applications (>100 W) such as USB PD 3.1 adapters, industrial chargers, and power tools.