For most applications, a 22µF nominal ceramic capacitor is recommended. The input capacitor buffers the input voltage for transient events and also decouples the converter from the supply. A X7R or X7T multilayer ceramic capacitor (MLCC) is recommended for best filtering and must be placed between VIN and GND as close as possible to those pins. For applications with ambient temperatures below 85°C, a capacitor with X5R dielectric can be used. Ceramic capacitors have a DC-Bias effect, which has a strong influence on the final effective capacitance. Choose the right capacitor carefully in combination with considering the package size and voltage rating. The minimum required input capacitance is 5µF.