An All-1.8-V-Switch Hybrid Buck–Boost Converter for Li-Battery-Operated PMICs Achieving 95.63% Peak Efficiency Using a 288-m DCR Inductor

authored by: Arindam Mishra, Wei Zhu, Bernhard Wicht, Valentijn De Smedt
Abstract: A hybrid step up/down converter is presented with improved efficiency, smaller form factor and enhanced reliability for Li-ion battery operated power management integrated circuits (PMICs). Utilizing a hybrid structure with one inductor and two flying capacitors, the dual-path buck-boost (DPBB) converter reduces the average inductor current, switch currents, and the required blocking voltage for the power switches. To support a mid-3V output from a Li-ion battery, the converter can be realized using 1.8V rated devices, solely. Additionally, the DPBB facilitates a continuous input and output current delivery, thus improving the reliability of the converter significantly. Besides, leveraging the Li-ion battery charge profile, the topology provides an optimal performance during down-conversion, in which the converter operates for most of its usage time. With reduced inductor current and smaller voltage rated switches, a more compact inductor with a large dc resistance (DCR) can be used to maintain similar efficiency, which in turn helps reducing the converter board-space and associated manufacturing cost. Fabricated in a 180 nm BCD technology, the prototype achieves a peak efficiency of 95.63<inline-formula><tex-math notation="LaTeX">$\%$</tex-math></inline-formula> even for a large 288 m<inline-formula><tex-math notation="LaTeX">$\Omega$</tex-math></inline-formula> inductor DCR with an output ripple below 20mV for a load current up to 700mA.
Organisation(s): Mixed-Signal Circuits Section
External Organisation(s): KU Leuven
Type: Article
Journal: IEEE Transactions on Power Electronics
Volume: 38
Pages: 3444-3454
No. of pages: 11
ISSN: 0885-8993
Publication date: 31.10.2022
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electrical and Electronic Engineering
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1109/tpel.2022.3218376 (Access: Closed)