Introduction

Abstract

DC-DC converters have been around since the use of electricity became common practice. Over the years many technological developments have led to a wide variety of different types and applications for DC-DC converters. In the recent years a trend has emerged towards very compact low-power (100 mW–1 W) and low-voltage (1 V–80 V) DC-DC converters, mainly for use in battery-operated applications. The two key specifications for this recent breed of DC-DC converters are power conversion efficiency and power density. DC-DC converters featuring high power conversion efficiency, only requiring a limited number of off-chip (passive) components are considered the established state-of-the art. The next technological step is to integrate the remaining off-chip components of the DC-DC converter on-chip, causing both the required area and the costs to decrease. The technology of choice to achieve this ongoing on-chip integration is CMOS, as it is by far the most widely used and thus potentially the most economical chip technology. This chapter provides some basic considerations and a few historical notes, in Sect. 1.1. Examples of low power applications for DC-DC converters situate the relevance of the work, in Sect. 1.2. The challenges of creating monolithic inductive DC-DC are highlighted in Sect. 1.3. The outline of this book is provided in Sect. 1.4. The conclusions of this chapter are given in Sect. 1.5.