TY - JOUR
T1 - A Low-Profile High-Efficiency Fast Battery Charger With Unifiable Constant-Current and Constant-Voltage Regulation
AU - Qu, Yong
AU - Shu, Wei
AU - Qiu, Lei
AU - Kuan, Yen Cheng
AU - Chiang, Shiuh Hua Wood
AU - Chang, Joseph S.
PY - 2020
Y1 - 2020
N2 - Present universal serial bus (USB) battery chargers often suffer from limitations to meet the increasing demand for quick charging due to compromised power efficiency and complicated hardware implementation. In this paper, we propose a charge unifiable (QU) control scheme that enables a battery charger to improve power efficiency in a low-profile hardware manner. This scheme features fully soft-switching (vis-à-vis hard switching) and single control scheme (vis-à-vis multiple) for distinct constant current (CC) and constant voltage (CV) charging modes. To the best of authors' knowledge, the proposed QU control scheme is the first to simultaneously offer fully soft-switching, innate CC-and-CV regulation, and seamless CC-to-CV transition. To verify the proposed design, we monolithically realize a low-profile high-efficiency fast battery charger based on this scheme. The prototype embodying a tiny 470-nH output inductor supports a maximum input voltage of 16V, output voltage of 2.2-4.2 V, output current of 0.1-2 A, and peak power efficiency of 96.2%. When benchmarked against state-of-the-art counterparts, the proposed charger features at least 2.1x smaller inductor and 7.2% higher power efficiency at both the maximum and the minimum output power charging scenarios. Further, this charger is the only design that features ≥ 91% power efficiency in the whole load range.
AB - Present universal serial bus (USB) battery chargers often suffer from limitations to meet the increasing demand for quick charging due to compromised power efficiency and complicated hardware implementation. In this paper, we propose a charge unifiable (QU) control scheme that enables a battery charger to improve power efficiency in a low-profile hardware manner. This scheme features fully soft-switching (vis-à-vis hard switching) and single control scheme (vis-à-vis multiple) for distinct constant current (CC) and constant voltage (CV) charging modes. To the best of authors' knowledge, the proposed QU control scheme is the first to simultaneously offer fully soft-switching, innate CC-and-CV regulation, and seamless CC-to-CV transition. To verify the proposed design, we monolithically realize a low-profile high-efficiency fast battery charger based on this scheme. The prototype embodying a tiny 470-nH output inductor supports a maximum input voltage of 16V, output voltage of 2.2-4.2 V, output current of 0.1-2 A, and peak power efficiency of 96.2%. When benchmarked against state-of-the-art counterparts, the proposed charger features at least 2.1x smaller inductor and 7.2% higher power efficiency at both the maximum and the minimum output power charging scenarios. Further, this charger is the only design that features ≥ 91% power efficiency in the whole load range.
KW - Batteries
KW - Battery charger
KW - Battery chargers
KW - control scheme
KW - high power efficiency.
KW - Inductors
KW - quick charging
KW - small size
KW - Switches
KW - Universal Serial Bus
KW - Zero current switching
KW - Zero voltage switching
UR - http://www.scopus.com/inward/record.url?scp=85089293296&partnerID=8YFLogxK
U2 - 10.1109/TCSI.2020.3007827
DO - 10.1109/TCSI.2020.3007827
M3 - Article
AN - SCOPUS:85089293296
JO - IEEE Transactions on Circuits and Systems I: Regular Papers
JF - IEEE Transactions on Circuits and Systems I: Regular Papers
SN - 1549-8328
ER -