David Baba
National Semiconductor

The design of the power architecture within the communications infrastructure market consists of many trade-offs and design considerations. Multiple factors such as input and output voltage, output current, space constraints, efficiency, as well as the priority the designer places on each of these needs, determine which topology should be used. This article addresses design considerations from a topology selection perspective, providing an overview of each topology's operation and the solution that is best implemented given the system's needs and the trade-offs involved.

Basic topology descriptions are provided along with waveforms. Equations are also provided which are useful for determining RMS ripple currents and losses in the pass elements.