Due to the nature of the switching converter with a pulsating input current, a low-ESR input capacitor is required for best input-voltage filtering and for minimizing the interference with other circuits caused by high input-voltage spikes. For the PVINx pin, 2.5 µF of input capacitance (after derating) is required for most applications. A ceramic capacitor is recommended to achieve the low-ESR requirement. However, the voltage rating and DC-bias characteristic of ceramic capacitors must be considered. For better input-voltage filtering, the input capacitor can be increased without any limit.

The preferred capacitor for the converters is one Samsung CL05A106MP5NUNC: 10 µF, 0402, 10 V, ±20%, or similar capacitor.