Switched-Capacitor Power Management Integrated Circuit for Autonomous Internet of Things Node

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 65; no. 10; pp. 1455 - 1459
• Main Authors: Grasso, A. D., Palumbo, G., Pennisi, S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-10-2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Batteries; Capacitors; Circuit design; CMOS; Converters; DC-DC converter; DC-DC power converters; Energy conversion efficiency; energy harvesting; Energy management; Integrated circuits; IoT node; Lithium; Lithium batteries; Power management; Resistance; Semiconductor devices; switched-capacitor converter; Switches; Switching circuits; Thin films; Transistors
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2018.2856260

A power management integrated circuit for an energy autonomous device is presented. It is based on a configurable 2:1 switched capacitor converter that is capable of delivering a maximum current to always-on and duty-cycled loads equal to 5 <inline-formula> <tex-math notation="LaTeX"> \mu \text{A} </tex-math></inline-formula> and 2 mA, respectively, from a thin-film 4.2-V lithium battery. The circuit is designed and implemented using the 0.8-<inline-formula> <tex-math notation="LaTeX"> \mu \text{m} </tex-math></inline-formula> CMOS transistors of a BCD technology and exploits off-chip ceramic capacitors. Power conversion efficiency as high as 93% in the active mode and 80% in the sleep mode, despite the large variation range of the output current, is achieved.