The device is designed to operate from an input voltage supply range between 0.5 V to 4.4 V. This input supply must be well regulated. If the input supply is located more than a few inches from the converter, additional bulk capacitance may be required in addition to the ceramic bypass capacitors. A typical choice is a tantalum or aluminum electrolytic capacitor with a value of 100 µF. The input power supply’s output current needs to be rated according to the supply voltage, output voltage and output current of the TPS61021A.