220.127.116.11.6 Input Capacitor Selection
Since a boost converter has continuous input current, the input capacitor senses only the inductor ripple current. The input capacitor value can be calculated by Equation 47 and Equation 48.
For this design to meet a maximum input ripple of 60 mV (1/2% of VIN nominal), a minimum 7.1-μF input capacitor with ESR less than 29 mΩ is needed. A 10-μF, X7R ceramic capacitor is selected.