An integrated circuit includes a gated circuit configured to operate on a first or second voltage, a header circuit, a first power rail and a second power rail on a back-side of a wafer, a third power rail on the back-side of the wafer, and a fourth power rail on a front-side of the wafer. The first and second power rail extend in a first direction, and are separated from each other in a second direction. The third power rail is between the first and second power rail in the second direction. The third power rail is configured to supply the second voltage to the gated circuit. The fourth power rail includes a first set of conductors extending in the second direction. Each of the first set of conductors is configured to supply a third voltage to the header circuit, and is separated from each other in the first direction.