Solar Battery Charger in CMOS 0.25 um Technology

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.