A Dual-Inductor Ladder Buck Converter for Li-Ion Battery-Operated Sub-Volt SoCs

authored by: Arindam Mishra, Wei Zhu, Bernhard Wicht, Valentijn De Smedt
Abstract: This article presents a dual-inductor ladder (DIL) hybrid buck converter to support system-on-chip (SoC)-compatible subvolt (<inline-formula> <tex-math notation="LaTeX">$\le$</tex-math> </inline-formula>1 V) supply rails directly from a single-cell Li-ion battery (2.5–5 V). Facilitating an extreme downconversion (16.67<inline-formula> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula>) using scaled CMOS technology, the proposed topology presents a unique solution to address the active versus passive component utilization while still neutralizing the well-known efficiency versus power density (PD) trade-off for a hybrid converter. The balanced inductor currents help reduce the average switch currents, improving active switch utilization, while the natural soft-charging of the flying capacitors reduces the switch rms currents, improving passive component utilization and PD. The DIL, thus, presents an optimal two-inductor solution for similar applications achieving excellent efficiency and PD. Fabricated in a 65 nm bulk CMOS technology, the DIL obtains 90.6% peak efficiency, 0.93 W/mm<inline-formula> <tex-math notation="LaTeX">$^2$</tex-math> </inline-formula> peak active PD (PPD) with a maximum power delivery of 1.35 W occupying just 1.13 mm<inline-formula> <tex-math notation="LaTeX">$^2$</tex-math> </inline-formula> die area.
Organisation(s): Mixed-Signal Circuits Section
External Organisation(s): KU Leuven
Type: Article
Journal: IEEE Journal of Solid-State Circuits
Volume: 59
Pages: 563 - 573
No. of pages: 11
ISSN: 0018-9200
Publication date: 02.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electrical and Electronic Engineering
Electronic version(s): https://doi.org/10.1109/jssc.2023.3313963 (Access: Closed)