INTRODUCTION
As system designers are forced to produce products with increased features while maintaining a flat or decreasing product cost, advancements in device technology must be considered. To produce Integrated Circuits (IC) with increased functionality at a reasonable cost, IC manufacturers need to reduce the overall silicon area. However, the functional and cost benefits associated with smaller areas can not be achieved without some system design trade-offs. These smaller geometry ICs typically have a maximum voltage rating of 3.0V or below, instead of the existing maximum 5.0V rating.

This application note is intended to provide the system designer with an overview of different options that could be used to down convert an existing 5.0V system rail to a regulated 3.0V.

The approaches discussed in this application note are the Low Dropout Regulator (LDO), charge pump and buck switch mode converter. Other options exist, but they do not provide a regulated 3.0V. A summary of these options, as well as a reference section containing detailed design application note titles and data sheets, appears at the end of the document.