Minimizing Leakage Power in CMOS Designs

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Project Summary: In many new designs, the leakage component of power consumption is comparable to the dynamic component. Many reports indicate that, in sub-65 nm CMOS technology node, 40% or even higher percentage of the total power consumption is due to the leakage of transistors and this percentage will increase with technology scaling unless effective techniques are used to bring leakage under control. This research focuses on minimizing leakage in CMOS VLSI circuits.

Minimizing Leakage Power in CMOS: Technology and Design Issues — This tutorial given at EPFL in July 2008 focuses on circuit techniques and design methods to accomplish this goal. The first part of the presentation provides an overview of basic physics and technology and scaling trends that have resulted in the significant increase in sub-threshold and gate leakage currents. The part provides an in-depth description of multiple, Vdd, multiple-Vt, and multiple Tox techniques for leakage minimization in light of process variations and substrate temperature changes. The second part of this presentation describes a number of design optimization techniques for controlling leakage current, including, state assignment, technology mapping, and precomputation-based signal guarding. It will also present runtime mechanisms for leakage control including body bias control, transition to minimum leakage state, and power gating.

Circuit and Design Automation Techniques for Leakage Minimization of CMOS VLSI Circuits — This tutorial given at Samsung Research in October 2006 focuses on circuit techniques and design methods to accomplish leakage minimization in CMOS VLSI circuits. The first part of the presentation provides an overview of basic physics and technology and scaling trends that have resulted in the significant increase in sub-threshold and gate leakage currents. The part provides an in-depth description of multiple, Vdd, multiple-Vt, and multiple Tox techniques for leakage minimization in light of process variations and substrate temperature changes. This part will address the use of high permittivity gate dielectric, metal gate, novel device structures and circuit-based techniques for controlling the gate tunneling current. The second part of this presentation describes a number of design optimization techniques for controlling leakage current, including, state assignment, technology mapping, and precomputation-based signal guarding. It will also present runtime mechanisms for leakage control including body bias control, transition to minimum leakage state, power gating, etc.