A smart and simple PV charger for portable applications

A smart and simple PV charger circuit is presented in this paper for the portable applications, which is only composed of several analog chips to simplify the system structure. A three-mode charging solution is employed to meet the demands of the PV array and the lithium battery, which includes the maximum power point tracking (MPPT) mode, the constant-voltage mode and the current-limited mode. Suitable charging mode can be achieved automatically by the smart switch to improve the utilization of the PV array and to protect the battery. The fractional open-circuit voltage method is employed to realize the MPPT performance due to its simple implementation performance. Furthermore, the proposed charger can be integrated into an IC chip to reduce the size and make it more attractive in the portable applications. At last, a 60 W prototype is built and tested to verify the effectiveness of the proposed solution.