Wu Xiao, Shi Yao, Jeloka Supreet, Yang Kaiyuan, Lee Inhee, Sylvester Dennis, Blaauw David
University of Michigan, Ann Arbor, MI.
Symp VLSI Circuits. 2016 Jun;2016. doi: 10.1109/VLSIC.2016.7573490. Epub 2016 Sep 22.
We present a discontinuous harvesting approach for switch capacitor DC-DC converters that enables ultra-low power energy harvesting. By slowly accumulating charge on an input capacitor and then transferring it to a battery in burst-mode, switching and leakage losses in the DC-DC converter can be optimally traded-off with the loss due to non-ideal MPPT operation. The harvester uses a 15pW mode controller, an automatic conversion ratio modulator, and a moving sum charge pump for low startup energy upon a mode switch. In 180nm CMOS, the harvester achieves >40% end-to-end efficiency from 113pW to 1.5μW with 66pW minimum input power, marking a >10× improvement over prior ultra-low power harvesters.
我们提出了一种用于开关电容DC-DC转换器的间断式采集方法，该方法能够实现超低功耗能量采集。通过在输入电容上缓慢积累电荷，然后以突发模式将其转移到电池中，可以在DC-DC转换器中的开关和泄漏损耗与非理想最大功率点跟踪（MPPT）操作所导致的损耗之间进行最佳权衡。该采集器采用一个15pW模式控制器、一个自动转换比调制器和一个移动求和电荷泵，以便在模式切换时实现低启动能量。在180nm互补金属氧化物半导体（CMOS）工艺中，该采集器在最低输入功率为66pW的情况下，实现了从113pW到1.5μW的端到端效率大于40%，相较于之前的超低功耗采集器有超过10倍的提升。
