A 1.5-Cycle Fast Sampling P-SSHC Piezoelectric Energy Harvesting Interface

This brief presents a 1.5-cycle fast sampling piezoelectric energy harvesting interface (PEHI) with the parallel synchronized switch harvesting on capacitor (P-SSHC) and leakage elimination. A 1.5-cycle fast sampling algorithm for the P-SSHC is proposed in this brief, which can quickly sample the open-circuit voltage and significantly reduce the power loss caused by the open-circuit sampling. Meanwhile, it ensures high tracking accuracy, and then increases the output power of the PEHI. Moreover, to solve the PEHI startup problem caused by the switch leakage of the P-SSHC, a leakage elimination switch (LES) is proposed. The proposed circuit is implemented in SMIC 0.18
$\mu \text{m}$
standard CMOS process, and the core area is
$1119\times 564\,\,\mu \text{m}^{2}$
. The sampling time of the proposed PEHI is 1.5 piezoelectric excitation cycles, and the power loss rate is 1.2%. The proposed PEHI can start up at the peak open-circuit voltage
$V_{POC}$
of 0.98 V, and the peak tracking efficiency can reach 99.1% in the range of
$V_{POC}$
from 1 V to 1.8 V. The maximum FOM of the proposed PEHI is improved by 1.4 times compared with the traditional FOCV PEHI.