The demand for power- and cost-efficient, fully integrated chip solutions is unyielding in today’s world of mobile, battery-operated electronics, and power-conditioning circuits are slowly and painfully rising to the challenge by integrating both power-intensive and power-efficient supply circuits in a single chip package. In spite of the low noise, high speed, and simplicity of linear regulators, switching power supplies are increasingly more appealing to the designer because not only is power efficiency higher, which is critical for long battery life, but its integration is also becoming practical. Modern switching regulator chips, in fact, now incorporate drivers, switches, compensation, and most impressively, magnetics [1-2], overcoming the historical shortcomings of integration. Unfortunately, building switching supplies that are almost as practical and simple to the end-user as linear regulators is expensive.
All-in-one, state-of-the-art supplies co-package power inductors and other large passives into a single chip, but do so at high cost. Not only is the size of the chip larger but the technologies used to build it are also costly. Consequently, to reap the full benefits of cost-efficient integration, active inductor multiplier circuits, which are relatively cheap and simple to integrate, can ease the burden of co-packaging technologies by enhancing and amplifying the functional characteristics of smaller, more cost-effective inductors .