This bypass operation mode helps optimizing battery utilization and achieving high efficiency while fresh batteries’ nominal voltage is in the same range with the converter’s output value. The MCP1641X can be powered by either single-cell, two-cell alkaline/NiMH batteries or single-cell Li-Ion/Li-Polymer batteries. A low-voltage designed architecture allows the regulator to start up without high inrush current or output voltage overshoot from a low input voltage.