Solar Battery Charger in CMOS 0.25 um Technology

Abstract

A solar cell powered Li-ion battery charger in CMOS 0.25um is proposed. The solar battery charger consists of a DC/DC boost converter and a battery charger. The voltage generated by a solar cell is up converted from 0.65V to 1.8V, which is used as the VDD of the battery charger. In this way, the solar battery charger automatically converts solar energy to electricity and stores it directly to a Li-ion rechargeable battery. In this system, a super capacitor is needed as a charge buffer between the boost converter and the charger.

Design and Simulation of Low Power and Voltage Micro Photovoltaic Cell for Mobile Devices

“…Research conducted by Arima and Ehara, by designing a on-chip solar battery based on 0.35µm CMOS technology which is integrated so that it becomes a chip, the voltage obtained is 600-830mV [1]. Research conducted by Wang, by designing a solar cell using 0.25µm CMOS technology to charge a Li-ion battery with a capacity of 1,8V, the output voltage obtained is around 650mV [4]. In this study, with the design and simulation of the micro photovoltaic cell circuit, the voltage obtained when the value of shunt resistance negative is around 200mV while when the value of shunt resistance positive is around 199mV.…”

“…In research conducted by Ferri et al, designed and developed an equivalent circuit for a micro photovoltaic cell based on 0.35µm CMOS technology and the resulting voltage was around 494 mV [2] [3]. In addition, research conducted by Wang et al, designed and developed a solar cell to charge Li-ion batteries with a capacity of 1,8V used 0.25µm CMOS technology, the resulted voltage was around 650mV [4].…”

“…This study designed and simulated the sensor part of a photovolaic IC, namely a micro photovoltaic cell to charge the battery on a smartphone. The purpose of this research is to design a micro photovoltaic cell circuit based on the research circuit reference paper by modifying the resistor value, so that the output can reach a power of around 1.5µW and a voltage of around 200mV [2], with the support of reference [1][3] [4]. Later, the series of micro photovoltaic cell will be implemented into 0.35µm CMOS technology.…”