T25.2 - A Three-Phase Hybrid Converter with 6× Duty-Cycle Extension and Fast Transient Response for Direct 48V-to-Pol Conversion

Thursday, March 26, 2026

8:40 AM - 9:00 AM CT

Location: 214A

Technical Lecture Presenter(s)

Yuxiao Yang (he/him/his)

University of Electronic Science and Technology of China

Presentation Paper

Co-Author(s)

HT

Hanbo Tu

University of Electronic Science and Technology of China
ST

Sasa Tong

University of Electronic Science and Technology of China
ZW

Zhengxi Wang

University of Electronic Science and Technology of China
ZY

Zheng Yang

University of Electronic Science and Technology of China
WC

Wanjun Chen

University of Electronic Science and Technology of China
Zekun Zhou, PhD (he/him/his)

University of Electronic Science and Technology of China
BZ

Bo Zhang

UESTC

This paper presents a novel three-phase sextuple step-down hybrid buck converter (TSHB) for direct 48V-to-PoL conversion. By reducing the voltage stress of inductor switching nodes to 1/6 VIN, the proposed TSHB achieves 6× duty-cycle extension and high efficiency with high figure-of-merit (FoM) devices. Additionally, the TSHB features self-balancing flying capacitor voltages and inherent phase current equalization, enabling reliable operation with a large output current. During heavy load transients, the unique transient state of the TSHB overcomes the 1/3 duty-cycle limit, resulting in over triple the total inductor current slew rate and markedly faster transient response. Experimental results validate the TSHB’s performance, demonstrating 86.5% peak efficiency at 48V-to-1V conversion with 333kHz switching per phase. Under a 50A load step within 500ns, TSHB exhibits only 178mV output voltage undershoot with 198μF output capacitance.