At its essence, the buck topology operates on the fundamental principles of energy conversion and control. The central tenet involves the periodic switching of a semiconductor device, often a MOSFET (PWM Controlled), to modulate the input voltage applied to an inductor. During the ON state, energy is stored in the inductor, and during the OFF state, this energy is released to the load. This cyclical process results in a regulated output voltage that is a fraction of the input voltage, constituting the core functionality of the buck converter.

Figure 3: Buck Topology when MOSFET is On

Figure 4: Buck Converter when MOSFET is Off