The TPS61251 device provides a power supply solution for products powered by either a three-cell, NiCd or NiMH battery, or a one-cell Li-Ion or Li-polymer battery. The wide input voltage range is ideal to power portable applications like mobile phones, solid state drives (SSD) and wireless modems. The converter is designed to charge large capacitors in the Farad range to support battery back up applications. During capacitor charging the TPS61251 is working as a constant current source until VOUT has reached its programmed value. The charge current can be programmed by an external resistor RILIM and provides a 10% accuracy for the average input current limit.