论文信息 - 20.10 A 50nW-to-10mW output power tri-mode digital buck converter with self-tracking zero current detection for photovoltaic energy harvesting

20.10 A 50nW-to-10mW output power tri-mode digital buck converter with self-tracking zero current detection for photovoltaic energy harvesting

Photovoltaic energy harvesting is an attractive method of developing battery-free systems for wireless sensors, biomedicai electronics, and the internet of things (IoT). To obtain an energy-efficient system, low-power digital circuits operating in the near/sub-threshold region are widely used in such applications. Therefore, the design of a low-voltage buck converter, which converts the harvested energy to the regulated output is critical. Sub-1V buck converters have been implemented using a large inductor [1] to operate in a continuous conduction mode (CCM). Both CCM and discontinuous conduction mode (DCM) operation has been demonstrated in [2], using an analog zero current detection (ZCD) technique to extend the available output power range. However, the analog circuit limits the minimum output power to 50μW, and reduces the conversion efficiency under light load conditions.

Po-Hung Chen | Chung-Shiang Wu | Kai-Chun Lin

[1] Seok-Jun Lee,et al. Microwatt Embedded Processor Platform for Medical System-on-Chip Applications , 2011, IEEE Journal of Solid-State Circuits.

[2] Kazunori Watanabe,et al. A 0.6 V Input CCM/DCM Operating Digital Buck Converter in 40 nm CMOS , 2014, IEEE Journal of Solid-State Circuits.

[3] Kazunori Watanabe,et al. A 0.45-V input on-chip gate boosted (OGB) buck converter in 40-nm CMOS with more than 90% efficiency in load range from 2µW to 50µW , 2012, 2012 Symposium on VLSI Circuits (VLSIC).

[4] Anantha Chandrakasan,et al. Minimum Energy Tracking Loop with Embedded DC-DC Converter Delivering Voltages down to 250mV in 65nm CMOS , 2007, 2007 IEEE International Solid-State Circuits Conference. Digest of Technical Papers.