A charging system that includes a switching control circuit coupled to four series-coupled MOSFET transistors; a flying capacitor coupled across two of the four series-coupled MOSFET transistors; and node between the two of the four series coupled transistors that couples to an output inductor to form a buck regulator is presented. Embodiments of the charging system can have increased efficiency, can reduce the size and inductance of the output inductor, and can be produced with a low voltage process.