A buck converter (buck converter) is a DC-DC power converter that steps down a voltage from its input to its output. High-efficiency variable step-down switch-mode DC-DC converters are used to design switching power supplies. The essential operation of a buck converter is that the current in the inductor is controlled by two switches (usually a transistor and a diode). Since DC/DC step-down (buck) converters have a controller with one or more integrated FETs and an external inductor, they strike a balance between flexibility and ease of use. Both non-synchronous (integrated high-side FET and external diode) and synchronous (integrated high-side and low-side FET) buck converters can simplify the design process by reducing the number of external components. Simultaneously, controlling the choice of external inductor allows you to optimize the power supply's efficiency, size, or cost.