The power supply can be three-cell alkaline, NiCd or NiMH, or
one-cell Li-Ion or Li-Polymer battery. The input supply should be well regulated
with the rating of TPS61253x. If the input supply is located more than a few
inches from the device, additional bulk capacitance may be required in addition to
the ceramic bypass capacitors. An electrolytic or tantalum capacitor with a value of
47 µF is a typical choice.