Voltage regulation of a series stacked system of digital loads by differential power processing

Das, Dipanjan

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https://hdl.handle.net/2142/98442 Copy

Description

Title

Voltage regulation of a series stacked system of digital loads by differential power processing

Author(s)

Das, Dipanjan

Issue Date

2016-04-28

Director of Research (if dissertation) or Advisor (if thesis)

Krein, Philip T.

Department of Study

Electrical & Computer Eng

Discipline

Electrical & Computer Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Differential Power Processing
• Series-stacked power delivery
• Series stacking
• Bidirectional power converters
• Light-load

Abstract

A modern high-end multi-core microprocessor has very stringent power supply requirements. It can draw hundreds of amperes of current at supply voltages as low as 0.8 V. As the supply voltages keep decreasing, the power delivery to meet the supply requirements is becoming increasingly difficult and inefficient. However, the presence of multiple cores in the microprocessor offers us a way to power it at a higher voltage by series-stacking the cores. Differential power processing has been shown to be an efficient way to series-stack server loads. In this work we study the dynamics of the element-to-element DPP topology implemented with bi-directional buck-boost converters. Some of its dynamic drawbacks are pointed out and a topological modification to counter those drawbacks is proposed. We then develop a linear control to regulate processor core voltages in a series stack of 4 cores. A hysteretic control to accommodate light load modes in the bi-directional regulating converters is also discussed. Both the linear and the hysteretic controller are implemented successfully in hardware and efficiency improvement due to light-load modes is demonstrated.

Graduation Semester

2016-05

Type of Resource

text

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http://hdl.handle.net/2142/98442

Copyright and License Information

Copyright 2016 Dipanjan Das

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