A battery-free energy harvesting system with the switch capacitor sampler (SCS) technique for high power factor in smart meter applications

This paper presented a battery-free energy harvesting system with an auto-startup mechanism to achieve AC power monitoring. The proposed switch capacitor sampler (SCS) technique suppresses the total harmonic distortion (THD) since the energy is derived from the AC power lines. It can improve the performance of the power factor correction (PFC) in the harvesting system to achieve high power utilization. As a result, the proposed method can be used as a smart meter for monitoring or controlling the power delivery decision. A battery-free energy harvesting system with the SCS control technique was implemented by using 0.25-μm CMOS process. The die area is 0.25 mm². The PF value can be raised to 0.98 with low THD of 17%.