This application note describes the selection considerations of output capacitors, based on load transient and output impedance of processors power rails. Presently, there are no specific tools available for non-Intel processor output capacitors selection in multiphase designs. In Part 1, the minimum required output capacitance to meet low repetitive rate load transient specifications is discussed. Part 2 will describe capacitor types and value to meet output impendence requirements, and also high rate repetitive load transient specifications. Analytical and experimental results show that output capacitors selection is optimized for load transient and output impedance, to fulfill non-Intel processor requirements.