how can the capacitor in DC-DC buck converter filter the ripple

The capacitor in a DC-DC buck converter acts as a filter for the ripple by smoothing out the voltage output. When the switch in the buck converter is closed, the capacitor charges up, storing energy. When the switch is opened, the capacitor discharges, providing energy to the load. This charging and discharging of the capacitor helps to smooth out the voltage output, reducing the ripple. The larger the capacitance of the capacitor, the better it can filter out the ripple. However, increasing the capacitance too much can increase the time required for the capacitor to charge and discharge, which can negatively affect the efficiency of the converter