8.2.2.5 Input and Output Capacitor Selection

The architecture of the TLV62585 allows use of tiny ceramic-type output capacitors with low equivalent series resistance (ESR). These capacitors provide low output voltage ripple and are thus recommended. To keep its resistance up to high frequencies and to achieve narrow capacitance variation with temperature, it is recommended to use X7R or X5R dielectric.

The input capacitor is the low impedance energy source for the converter that helps provide stable operation. A low ESR multilayer ceramic capacitor is recommended for best filtering. For most applications, 10-μF input capacitor is sufficient; a larger value reduces input voltage ripple.

The TLV62585 is designed to operate with an output capacitor of 10 μF to 47 μF, as outlined in Table 4.

A feed forward capacitor reduces the output ripple in PSM and improves the load transient response. A 22-pF capacitor is good for the 1.8-V output typical application.