A novel method for audible noise suppression and enhanced efficiency using hybrid buck-pseudo-boost converter

In this paper, a Hybrid Buck–Pseudo-Boost (HBPB) converter with a closed-loop voltage-zero-cross detection (V-ZCD) control scheme was fabricated in a 0.13-μm Bipolar-CMOS-DMOS (BCD) process, which locks the minimum switching frequency and activates a pseudo-boost energy recycling mode. The HBPB achieves high efficiency and low noise operation under light loads and seamless mode transition across the full load range. The experimental results demonstrate that the HBPB converter maintains a switching frequency of 36 kHz under a 0.01 A load and achieves a peak conversion efficiency of 94% at a moderate load of 0.8 A. Additionally, adaptive switching among CCM, DCM, and buck-pseudo-boost modes is achieved over a 0–6 A load range, with transient voltage deviation constrained to within 100 mV. The HBPB energy-recycling architecture effectively mitigates the efficiency–audible noise trade-off inherent in conventional light-load buck operation and is well-suited for noise-sensitive portable and Internet-of-Things power management applications. Further improvements in reverse-current regulation accuracy and control-loop simplification will enhance integration scalability and practical deployment.