A reconfigurable switched-capacitor DC-DC converter for millimiter-scale energy harvesting sensor nodes
- Wireless sensor nodes are the key building blocks for realizing the Internet of Everything (IoE). Conventionally, batteries have been utilized to power IoE-type devices; however, batteries have a limited lifetime and therefore need to be re-placed or recharged. They also increase the size and cost of the sensor node. Therefore, batteries do not offer a viable solution to power billions of IoE devices in the future. An alternative approach to power wireless sensors is ambient energy harvest-ing. In an ambient energy harvesting sensor node, a transducer converts a form of ambient energy such as light, vibration, or temperature difference to electrical en-ergy. Then, a power management circuit converts the volatile electrical power generated by the harvester to a regulated supply for sensor circuits. This talk presents the design, implementation and measurements of a power management IC for mm-scale energy harvesting wireless sensor nodes. Our pow-er management IC uses the series-parallel switched-capacitor architecture and has the following characteristics. First, to support the wide input voltage range of the energy harvester, the converter is designed to be reconfigurable: It adjusts its voltage gain dynamically to regulate the output voltage of the converter within a target window. Second, our design automatically adjusts its operating frequency based on the current consumption of the load circuits to achieve high efficiency. This power management IC has been fabricated in a 0.25-μm CMOS process and operates with an input voltage ranging from 0.6 V to 2.4 V, from which the con-verter generates a regulated 1.2 V output rail with a maximum load current of 100 μA. The maximum power conversion efficiency is 78% and remains above 60% across a wide range of input voltages and load currents.
|Type of resource
|electronic; electronic resource; remote
|1 online resource.
|Stanford University, Department of Electrical Engineering.
|Statement of responsibility
|Submitted to the Department of Electrical Engineering.
|Thesis (Ph.D.)--Stanford University, 2015.
- © 2015 by Seyed Mahmoudreza Saadat
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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