Embedded control firmware optimization for power electronics

Abstract

Modern power converters face quicker input and load changes. With higher switching frequency and smaller inductors or capacitors, there is less stored energy to smooth disturbances. If the control reacts slowly, voltage or current overshoots or undershoots will take longer to settle, resulting in energy waste and potential damage to the device. Therefore, a faster response is needed in the power electronics system. Embedded control firmware plays a key role in improving closed-loop speed and system stability. In high-frequency DC-DC converters and automotive power electronics, firmware execution performance directly affects control accuracy, energy efficiency, and system robustness. In this thesis, we compare three automotive-grade MCUs—TI F29H85x, TI AM263x, and Infineon AURIX TC4x—under a unified closed-loop control framework. By dividing the control loop into stages such as ADC sampling, PID calculation, and PWM output, and by analyzing differences in interrupt systems, CPU architecture, peripheral interconnect, and compiler optimization, we systematically show their impact on execution delay. Delay is measured using GPIO toggling and interrupt timestamps, and platform-specific optimizations (such as DMA acceleration, early interrupt mode, memory mapping, compiler tuning, and CDSP/PPU offloading) are applied to explore the shortest possible execution time. Results show that all three MCUs achieved significant improvements over their baselines, with F29H85x reaching 710 ns, AM263x 793 ns, and TC4x 750 ns. The contribution of this project is not only to compare real-time performance across MCUs, but also to propose a unified cross-platform analysis method. By linking experimental results with structural differences, we show how interrupt paths, CPU pipelines, and peripheral interconnects determine real-time performance. This approach goes beyond single-platform studies, providing a systematic framework for analysis. It also offers practical guidance for MCU selection and firmware optimization in industrial applications.