Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A 30nA Quiescent 80nW to 14mW Power Range Shock-Optimized SECE-based
  Piezoelectric Harvesting Interface with 420% Harvested Energy Improvement   Piezoelectric Energy Harvesters (PEH) are usually used to convert mechanical
energy (vibration, shocks) into electrical energy, in order to supply
energy-autonomous sensor nodes in industrial, biomedical or domotic
applications. Non-linear extraction strategies such as Synchronous Electrical
Charge Extraction (SECE) [1-2], energy investing [3] or Synchronized Switch
Harvesting on Inductor (SSHI) [4] have been developed to maximize the extracted
energy from harmonic excitations. However, in most of today's applications,
vibrations are not periodic and mechanical shocks occur at unpredictable rates
[4]. SSHI interfaces naturally seemed to be the most appropriate candidate for
harvesting shocks as they exhibit outstanding performance in periodic
excitations [4]. However, the SSHI strategy presents inherent weaknesses while
harvesting shocks, since the invested energy stored in the piezoelectric
capacitance cannot be recovered. In this work, we propose a self-starting,
battery-less, 0.55mm 2 integrated energy harvesting interface based on SECE
strategy which has been optimized to work under shock stimulus. Due to the
sporadic nature of mechanical shocks which imply long periods of inactivity and
brief energy peaks, the interface's average consumption is optimized by
minimizing the quiescent power. A dedicated energy saving sequencing has thus
been designed, reducing the static current to 30nA and enabling energy to be
extracted with only one single 8$\mu$J shock occurring every 100s. Our
SECE-based circuit features a shock FoM 1.6x greater than previous SSHI-based
interfaces [4]. The proposed system depicted in Fig.1 is made of a negative
voltage converter rectifying the PEH output voltage, and a SECE power path
controlled by a sequenced circuit. The sequencing is divided in 4 phases and
the associated time diagrams are illustrated in Fig.2. During the sleeping mode
T1, all blocks except the shock detection (SD) are turned off. During the
starting phase, the energy is stored in CASIC through a cold-start path,
increasing VASIC. This will progressively turn on the SD. Next, when stress
applied to the piezoelectric material leads to an increase in VREC, the SD
checks if the electrical energy

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The categories of this paper are: hep-ph
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The categories of this paper are: cs
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The categories of this paper are: eess
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The categories of this paper are: funct-an
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The categories of this paper are: cond-mat
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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: gr-qc
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The categories of this paper are: astro-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: hep-lat
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The categories of this paper are: cmp-lg