A 233-MHz 80%-87% efficient four-phase DC-DC converter utilizing air-core inductors on package

A Distributed Filter Within a Switching Converter for Application to 3-D Integrated Circuits

“…7(d). The general trend for all output DC voltages is that the filter efficiency increases with higher , as evident from (18) and (20). From Figs.…”

“…To improve the quality factor of a 2 nH inductor and reduce the ripple current within the inductors, magnetic coupling between two on-chip inductors has been used in a dc-dc converter [17]. Although the size and magnitude of the on-chip inductors and capacitors required to implement a buck converter are reduced with increasing switching frequency, the on-chip passive devices comprising the filter are large and cannot be practically integrated in the megahertz frequency regime [18]- [20].…”

Energy Efficient Block-Partitioned Multicore Processors for Parallel Applications

“…For non-real-time applications, Donald et al concluded that the most effective approach for energy management in multicore-based systems is the combination of core throttling (i.e., powering off the unused cores) and per-core DVFS that adjusts the processing frequency and supply voltage of cores independently [16]. Although it is possible to provide a separate power supply voltage for each individual core to get the maximum flexibility, as the number of cores on a chip continues to increase (with tens [50] or even hundreds of cores [22]), the increased overhead [20] of such a feature may come with additional circuit complexity, stability, and power delivery problems [8,21,38].…”

“…and on-chip voltage regulators [20] would make it very costly to support a separate DVFS-enabled supply voltage for each core, especially considering that the number of cores on a single chip continues to increase (where extensive research activity is underway to build chips with potentially tens and even hundreds of cores [8,22,38]). Therefore, the problem of how to optimally place the cores on different voltage islands in a multicore chip for effective system-level power management remains open.…”

Efficiency optimization of integrated DC-DC buck converters

“…The target converter supports 2 volts to 1 volt conversion, a filter inductor of 3 nH embedded in a package [6], and a switching frequency in the range of hundreds of MHz. The maximum load is targeted at 1.5 amperes.…”