CMOS Modified Differential Voltage Multiplier Co-integrated with Indoor Photovoltaic Energy Harvesting in 65nm CMOS Process for WSN Application

This circuit design presents a CMOS Modified Differential Voltage Multiplier co-integrated with indoor photovoltaic energy harvesting circuit for Wireless Sensor Node device in 65nm CMOS process. This work aims to supply power in Microsemi's ZL70250, a wireless sensor network transceiver. Extraction of high DC voltage from rectifier block is always a serious bottleneck for energy harvesting. Consequently in this work, a simple mechanism to eliminate (Vth) of the MOS transistor by adding an auxiliary Pmos is proposed. Also, an additional capacitor (Cs) has been split into two capacitors that have been connected to the differential output. For analysis and comparison, the traditional and proposed voltage multiplier circuit is simulated and implemented with 3 stages with load capacitance of 100pF. The proposed voltage multiplier obtains a higher voltage conversion ratio (Gv) of 3.96, much higher than the reference voltage multiplier. The Gv and the generated boosted rectifier output voltage was obtained from 0.5V single PV. The modified architecture is integrated in indoor photovoltaic energy harvesting circuit. Accordingly, with this modification and implementation, this work able to supply power for Microsemi's ZL70250 that requires 1.2V to 1.8V and less than 1.9mA to operate.