A power management integrated circuit including: a clock generator that generates an input clock; a first phase delay controller that delays the input clock by a first phase and outputs a first supply clock to a first switching converter; a second phase delay controller that delays the input clock by a second phase and outputs a second supply clock to a second switching converter; and a third phase delay controller that delays the input clock by a third phase and outputs a third supply clock to a third switching converter, wherein the first phase, the second phase and the third phase have different phases from each other.