T25.5 - Interphase LC-Oscillation Suppression with Fast Line-Transient Response in 48-V Series-Capacitor Buck Converters for Automotive Applications

Thursday, March 20, 2025

9:20 AM – 9:40 AM ET

Location: Level Three, A302

Technical Lecture Presenter(s)

Wan Lin Jiang, MASc

University of Toronto

Presentation Paper

Co-Author(s)

YL

Yongxi Liu

University of Toronto
Nameer Ahmed Khan

University of Toronto
University of Toronto
VC

Vikram Chaturvedi

NXP Semiconductors
John Pigott

NXP Semiconductors
HB

Henk Jan Bergveld

NXP Semiconductors
Olivier Trescases

University of Toronto

This work presents a 4:1 series-capacitor buck (SCB) converter for 48 V-to-0.8V automotive applications, designed with enhanced input transient response using current-mode control. In this work, interphase LC oscillations, characteristic of hybrid dc-dc converters, are damped through dynamic flying-capacitor voltage tracking. The proposed active tracking scheme is essential for current balancing in a current-mode controlled SCB converter. Unlike existing multiphase current balancing methods, the proposed solution employs a combination of two flying-capacitor voltage regulators to adjust each phase’s current command. The improved converter dynamics under a fast input voltage step are experimentally verified using a 50-W, 200-kHz prototype.