TY - GEN
T1 - A 96.8%-Efficiency Continuous Input/Output-Current Step-Up/Down Converter Powering Disposable IoTs with Reconfigurable Multi-Cell-Balanced Alkaline Batteries
AU - Ko, Min Woo
AU - Kang, Gyeong Gu
AU - Kim, Ki Duk
AU - Lee, Ji Hun
AU - Koh, Seoktae
AU - Kong, Taehwang
AU - Kim, Sang Ho
AU - Lee, Sungyong
AU - Choi, Michael
AU - Shin, Jongshin
AU - Cho, Gyu Hyeong
AU - Kim, Hyun Sik
N1 - Publisher Copyright:
© 2020 IEEE.
PY - 2020/2
Y1 - 2020/2
N2 - As internet-of-things (IoT) devices continue to be installed everywhere, the concept of disposable IoT is emerging owing to better cost-efficiency and ease of maintenance without battery recharging. Lasting several years, IoTs powered with standard alkaline batteries can be a promising solution due to the long shelf life, low cost, and high reliability of these batteries as compared to the Li-ion type. As shown in the top portion of Fig. 11.8.1, a single alkaline cell has a maximum voltage of 1.5V, but it can decay down to 0.9V [1]. To power an IoT device operating with mathrm{V} {mathrm{DD}}=2mathrm{V}, a variety of design options can be considered, such as the battery configuration and the power conversion topology, as shown in Fig. 11.8.1 (bottom). The first approach is step-down conversion [2], [3] from multi-cell batteries (3×BATs) connected in series. In this configuration, cell-balancing must be carefully considered; otherwise, the energy of the BATs cannot be fully utilized if any weak cells exist among them. Considering the power conversion stage, the input RMS current mathrm{I} {mathrm{IN},mathrm{RMS}} becomes much higher than the average current mathrm{I} {mathrm{IN},mathrm{AVG}} due to the inherently discontinuous mathrm{I} {mathrm{IN}} supplied from batteries, resulting in a significant power loss in the series combination of the direct current resistance (mathrm{R} {mathrm{DCR}, mathrm{BAT}}) of batteries which in the case of 3 batteries in series is 3times mathrm{R} {mathrm{DCR}, mathrm{BAT}} (-300m Omega). Regarding step-up conversion [4], [5] with parallel-connected batteries, most of the energy imbalances are compelled to be uselessly wasted via reverse currents mathrm{I} {mathrm{B}} ' The mathrm{I} {mathrm{B}} also can cause explosion or leakage of corrosive substances. Furthermore, the inductor current mathrm{I} {mathrm{L}} is likely to be high, caused by the discontinuous mathrm{I} {mathrm{D}} delivered to the output; this significantly contributes to the power loss with a large mathrm{R} {mathrm{DCR},mathrm{IND}} of the inductor. In summary, the battery cell imbalance and the discontinuous input/output (I/O) current of converter are perhaps the major issues that prevent the full utilization of alkaline batteries in IoT applications.
AB - As internet-of-things (IoT) devices continue to be installed everywhere, the concept of disposable IoT is emerging owing to better cost-efficiency and ease of maintenance without battery recharging. Lasting several years, IoTs powered with standard alkaline batteries can be a promising solution due to the long shelf life, low cost, and high reliability of these batteries as compared to the Li-ion type. As shown in the top portion of Fig. 11.8.1, a single alkaline cell has a maximum voltage of 1.5V, but it can decay down to 0.9V [1]. To power an IoT device operating with mathrm{V} {mathrm{DD}}=2mathrm{V}, a variety of design options can be considered, such as the battery configuration and the power conversion topology, as shown in Fig. 11.8.1 (bottom). The first approach is step-down conversion [2], [3] from multi-cell batteries (3×BATs) connected in series. In this configuration, cell-balancing must be carefully considered; otherwise, the energy of the BATs cannot be fully utilized if any weak cells exist among them. Considering the power conversion stage, the input RMS current mathrm{I} {mathrm{IN},mathrm{RMS}} becomes much higher than the average current mathrm{I} {mathrm{IN},mathrm{AVG}} due to the inherently discontinuous mathrm{I} {mathrm{IN}} supplied from batteries, resulting in a significant power loss in the series combination of the direct current resistance (mathrm{R} {mathrm{DCR}, mathrm{BAT}}) of batteries which in the case of 3 batteries in series is 3times mathrm{R} {mathrm{DCR}, mathrm{BAT}} (-300m Omega). Regarding step-up conversion [4], [5] with parallel-connected batteries, most of the energy imbalances are compelled to be uselessly wasted via reverse currents mathrm{I} {mathrm{B}} ' The mathrm{I} {mathrm{B}} also can cause explosion or leakage of corrosive substances. Furthermore, the inductor current mathrm{I} {mathrm{L}} is likely to be high, caused by the discontinuous mathrm{I} {mathrm{D}} delivered to the output; this significantly contributes to the power loss with a large mathrm{R} {mathrm{DCR},mathrm{IND}} of the inductor. In summary, the battery cell imbalance and the discontinuous input/output (I/O) current of converter are perhaps the major issues that prevent the full utilization of alkaline batteries in IoT applications.
UR - http://www.scopus.com/inward/record.url?scp=85083846682&partnerID=8YFLogxK
U2 - 10.1109/ISSCC19947.2020.9062896
DO - 10.1109/ISSCC19947.2020.9062896
M3 - Conference contribution
AN - SCOPUS:85083846682
T3 - Digest of Technical Papers - IEEE International Solid-State Circuits Conference
SP - 204
EP - 206
BT - 2020 IEEE International Solid-State Circuits Conference, ISSCC 2020
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2020 IEEE International Solid-State Circuits Conference, ISSCC 2020
Y2 - 16 February 2020 through 20 February 2020
ER -