A Power Management Integrated Circuit (PMIC) that includes a substrate, a high-side (HS) region on the substrate, a low-side (LS) region spaced from the first region, a device isolation layer interposed between the HS region and the LS region, a metal interconnection connected to the HS region across the device isolation layer and configured to permit a high-voltage current to flow in the HS region, and at least one electric field shield between the metal interconnection and the device isolation layer. Since the electric field shield is disposed under the metal interconnection, a sufficient breakdown voltage can be ensured for the HS region and the LS region.