Efficient SSHI circuit for piezoelectric energy harvester uses one shot pulse boost converter

In this paper, a one shot pulse inductor boost converter is presented which provides 4 V output at 60 ms of delay using 0.15 V vibration source. Energy harvesting plays an important role in biomedical implants sensors where the extended life time is the most prominent factor. Synchronized switch harvesters on inductor (SSHI) comes into existence due to its highly efficient interface with energy harvesters. The main aim of this paper is to obtain high efficiency and maximum power extraction from piezoelectric energy harvester using SSHI and one shot pulse boost converter. This circuit does not require any external voltage and provides the controlled output with reduced power dissipation of approximately 10 nW and power consumption achieves between 1 and 10 mW. The start-up problem due to variable vibrational energy source is avoided by using one shot pulse inductor boost converter. This converter uses only one shot period for maximum charge transfer during first switching cycle. In 180 nm CMOS process, result shows that pulse boost converter can be directly powered from low voltage of 0.15 V with efficiency of ≈ 90% across the load of 6 µA current having switching frequency of 206 kHz. It also eliminates the problem of switching losses and reduces leakage current by saving board space and external components cost.