New types of sophisticated field-programmable devices (FPDs), have dramatically changed the process of digital design over the past few years. Unlike previous generations of technology, in which board-level designs included large numbers of SSI chips containing basic gates, virtually every digital design produced today consists mostly of high-density devices. When such circuits need to be used for high-volume systems they have been integrated into high-density gate arrays. As the complexity of these programmable devices increase their power supply design also required careful considerations. The purpose of this paper is to provide an insight into the power supply requirements for these devices along with a few reference designs.