Tim Hegarty
National Semiconductor

The Xilinx Virtex-5 and Altera Stratix III are families of advanced field programmable gate arrays (FPGAs) based on 65-nm cores that combine various platforms and speed grades, enabling a high level of performance and flexibility. This application note discusses FPGA power supply prerequisites in regard to multiple voltage rail and current level requirements, output sequencing, and startup characteristics. It also presents a power supply design based on National Semiconductor's LM1771 and LM3880, that combines high performance, power density and efficiency.