The input capacitor is the low-impedance energy source for the converters which helps to provide stable operation. A low-ESR multilayer ceramic capacitor is recommended for best filtering and must be placed between VIN and GND as close as possible to those pins. For most applications, 4.7 μF is sufficient, though a larger value reduces input current ripple.
The architecture of the device allows the use of tiny ceramic output capacitors with low equivalent series resistance (ESR). These capacitors provide low output voltage ripple and are recommended. To keep its low resistance up to high frequencies and to get narrow capacitance variation with temperature, TI recommends using X7R or X5R dielectrics. The recommended typical output capacitor value is 2 × 10 μF or 1 × 22 µF; this capacitance can vary over a wide range as outline in the output filter selection table.
A feedforward capacitor is required for the adjustable version, as described in Section 18.104.22.168. This capacitor is not required for the fixed output voltage versions.