A Rectifier-Reusing Bias-Flip Energy Harvesting Interface Circuit With Adaptively Reconfigurable SC Converter for Wind-Driven Triboelectric Nanogenerator

The energy harvesting interface circuit is proposed for wind-driven triboelectric nanogenerator (WD-TENG). To extract power from the WD-TENG maximally and deliver power to the output (battery) efficiently, a rectifier-reusing bias-flip (RRBF) technique and a multiphase reconfigurable switched-capacitor converter (MRSCC) are developed. In the RRBF, the low-side switches of the rectifier are reused as switches for bias-flip without additional components. The MRSCC delivers power to the battery efficiently by reducing switching loss including overlap loss. Furthermore, the MRSCC maintains a rectified voltage (
V
_RECT
) as high as a breakdown voltage (
V_BR
) of a switch by adaptive conversion control and multiphase operation to extract maximized power from the WD-TENG in a given process, even if the battery voltage is varied from 2.7 to 4.2 V. Owing to the proposed techniques, the maximum extracted power to the output is 238 μW and peak power delivering efficiency of the MRSCC is 79.3%. The chip was fabricated in 0.18 μm BCD process.