Implicit dc-dc conversion through charge-recycling for dynamic voltage scaling and high-voltage power delivery

This dissertation describes an energy-efficient means to achieve on-chip dc-dc conversion for digital CMOS circuits. This approach uses balanced voltage islands running at fractions of the off-chip supply voltage. Charge "discarded" by one domain is "recycled" to supply energy to another. When the domains are ideally balanced, all the energy dissipated by electrons in "dropping" to lower potentials is used for active computation. We achieve this implicit dc-dc conversion with very high energy efficiencies and little area overhead. We have demonstrated this implicit energy-efficient dc-dc conversion technique for two applications---dynamic voltage scaling and high-voltage power delivery.; In the dynamic voltage scaling application we have shown the ability to run the digital circuits at multiple voltage ranges with very little area overhead and high energy efficiency. The design has the ability to dynamically adjust itself to get maximum energy efficiency in the system.; A high-voltage power delivery system delivers power with reduced current demands and power-ground network impedances. The design consists of stacked thin-oxide CMOS logic domains operating at multiples of the supply voltage.; We describe the design and measurement of a prototype system in a 0.18 mu m CMOS process that provides active on-chip voltage regulation and controlled dc-dc conversion with this technique. We have shown 93% energy efficiency in the conversion.