Fast Digital Cross–Coupled Phase Control to Maintain 180° Interleaving in BCM/DCM Boost PFC

This paper presents a cross-coupled, closed-loop digital phase control strategy for two-phase interleaved boost power factor correction (PFC) converters operating in boundary conduction mode (BCM) and discontinuous conduction mode (DCM). Implemented on a DE1-SoC platform, the proposed control scheme utilizes a non-master-slave architecture that integrates per-cycle period measurement with a predictive scheduling algorithm. A key advantage of this approach is its capability to achieve deadbeat-like phase response and maintain a highly stable 180° phase shift. Unlike open-loop methods, the proposed controller derives timing constraints from the slower phase to effectively mitigate phase drifting caused by component mismatches and switching frequency variations. Experimental results from a 300 W prototype confirm the design's effectiveness: the precise interleaving maximizes input current ripple cancellation, achieving a 50% reduction in peak-to-peak ripple compared to non-interleaved operation. This stability significantly reduces stress on passive components and optimizes electromagnetic interference (EMI) performance, validating the solution for compact, high-performance front-end power supplies.