Biomedical implants, wearable technology, and Internet of Things (IoT) wireless sensor nodes continue to drive the need for high-efficiency, miniaturized, low-powered devices. These implantable and/or wearable miniaturized devices are typically implemented as system-on-chip packages that rely on micro-energy harvesting that uses DC-DC boost converters for maintaining optimal voltage and power conversion efficiencies.
Compared to an inductor-based converter, a capacitive-based converter, referred to as a charge pump (CP), is preferred since it does not require any bulky off-chip inductor and is suited for nanoscale implementation. CPs are DC-DC boost converters which take a voltage input and a combination of capacitors, diodes, and/or switches to deliver an output voltage several times higher than the input. While initially, CPs were used in systems such as flash memory, electrically erasable programmable read-only memory (EEPROM), and other low-power devices, they are now being pursued for use in biomedical and IoT applications. There are multiple designs for the implementation of CPs, and while some are simpler, each design has specific criteria to consider for the final circuit. Often, MOS transistors are used as diodes as they can be controlled more precisely, functioning as a switch.
This chapter will provide a review of different CP topologies, design considerations, and possible future nanoscale implementation when the output of the energy harvester is on the order of a few hundred millivolts.
- Charge pump circuits for biomedical and IoT applications in nanoelectronics
- Mohammad Karim - Department of Electrical and Computer EngineeringLeandro D. Neves
- Low-Dimensional Materials, Systems, and Applications, Volume 2, pp.85-109
- Elsevier Ltd
- Department of Electrical and Computer Engineering
- English
- Book chapter
- 044344594X; 9780443445934; 9780443445941; 0443445931
- https://doi.org/10.1016/B978-0-443-44593-4.00003-1
- 9914539679001301