This paper presents experimental results from a system that comprises a fully autonomous energy harvester with a solar cell of 1 mm² as energy transducer and a Power Management Unit (PMU) on the same silicon substrate, and an output voltage regulator. Both chips are implemented in standard $0.18~\mu \text{m}$ CMOS technology with total layout areas of 1.575 mm² and 0.0126 mm², respectively. The system also contains an off-the-shelf 3.2 mm $\times2.5$ mm $\times0.9$ mm supercapacitor working as an off-chip battery or energy reservoir between the PMU and the voltage regulator. Experimental results show that the fast energy recovery of the on-chip solar cell and PMU permits the system to replenish the supercapacitor with enough charge as to sustain Bluetooth Low Energy (BLE) communications even with input light powers of 510 nW. The whole system is able to self-start-up without external mechanisms at 340 nW. This work is the first step towards a self-supplied sensor node with processing and communication capabilities. The small form factor and ultra-low power consumption of the system components is in compliance with biomedical applications requirements.

中文翻译：

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用于生物医学应用的具有冷启动和调节输出电压的片上太阳能收集器和 PMU

本文介绍了一个系统的实验结果，该系统包括一个完全自主的能量收集器，带有一个 1 毫米²太阳能电池作为能量传感器，一个电源管理单元 (PMU) 位于同一硅基板上，以及一个输出电压调节器。两种芯片均以标准实现 $0.18~\mu \text{m}$ 总布局面积分别为 1.575 mm ²和 0.0126 mm ^{2 的}CMOS 技术。该系统还包含一个现成的 3.2 毫米 $\times2.5$ 毫米 $\times0.9$ mm 超级电容器用作 PMU 和稳压器之间的片外电池或能量储存器。实验结果表明，片上太阳能电池和 PMU 的快速能量回收允许系统为超级电容器补充足够的电荷，以维持低功耗蓝牙 (BLE) 通信，即使输入光功率为 510 nW。整个系统能够在 340 nW 的功率下在没有外部机制的情况下自启动。这项工作是迈向具有处理和通信能力的自供电传感器节点的第一步。系统组件的小尺寸和超低功耗符合生物医学应用要求。