The present disclosure provides a buck converter for achieving a high output and reducing cost. The buck converter includes: a MOSFET, including a first side connected to an application end of an input voltage; a rectifying element, connected to a second side of the MOSFET by a first connection node; a coil, having a first terminal connected to the first connection node; and an output capacitor, connected to a second terminal of the coil. The MOSFET is a super-junction MOSFET.