Files in this item



application/pdfSTILLWELL-THESIS-2015.pdf (3MB)
(no description provided)PDF


Title:Differential power processing for series-stacked processors
Author(s):Stillwell, Andrew R
Advisor(s):Pilawa, Robert
Department / Program:Electrical & Computer Engineering
Discipline:Electrical & Computer Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Abstract:The series-stacked architecture provides a method to increase power delivery efficiency to multiple processors. With a series-stack, differential power processing (DPP) is needed to ensure that processor voltages remain within design limits as the individual loads vary. This work demonstrates a switched-capacitor (SC) converter to balance a stack of four ARM Cortex-A8 based embedded computers. A model of a series-stack with no DPP is first discussed for the case when loads can be controlled with no power electronics. We investigate hard-switched and resonant modes of operation in a ladder SC DPP converter, implemented with GaN transistors. Excellent 5 V regulation of each embedded computer is demonstrated in a 4-series-stack configuration, with realistic computational workloads. Moreover, we demonstrate hot-swapping of individual computers with maintained voltage regulation at all nodes. A peak stack power delivery of 99.8% is demonstrated, and DPP switching frequencies from 250 kHz to 2 MHz. Finally, the reliability of a series-stacked system is compared to an electrically parallel system.
Issue Date:2015-07-21
Rights Information:Copyright 2015 Andrew Stillwell
Date Available in IDEALS:2015-09-29
Date Deposited:August 201

This item appears in the following Collection(s)

Item Statistics