The invention relates to a buck converter including a first high-side switch circuit having an input terminal electrically connected to a first power input terminal, a control terminal electrically connected to a first control signal source, and an output terminal; a second high-side switch circuit having an input terminal electrically connected to a second power input terminal, a control terminal electrically connected to a second control signal source, and an output terminal electrically connected to the output terminal of the first high-side switch; a lower-side switch circuit having a first terminal electrically connected to the output terminal of the first high-side switch and a second terminal electrically connected to a reference power terminal; and a filter electrically connected to the output terminal of the first high-side switch and a power output terminal, wherein the first and second high-side switch circuits will not turn on at the same time.