"CMOS technology has scaled aggressively over the past few decades in an effort to enhance functionality, speed and packing density per chip. As the feature sizes are scaling down to sub-100nm regime, leakage power is increasing significantly and is becoming the dominant component of the total power dissipation. Major contributors to the total leakage current in deep submicron regime are subthreshold and gate tunneling leakage currents. The leakage reduction technique developed so far were mostly devoted to reducing subthreshold leakage. However, at sub-65nm feature sizes, gate leakage current grows faster and is expectedd to surpass subthreshold leakage current. In this work, an extensive analysis of the circuit level characteristics of subthreshold and gate leakage currents is performed at 45nm and 32nm feature sizes. The analysis provides several key observations on the interdependency of gate and subthreshold leakages currents. Based on these observations, a new leakage reduction technique is proposed that optimizes both the leakage currents. This technique identifies minimum leakage vectors for a given circuit based on the number of transistors in OFF state and their position in the stack. The effectiveness of the proposed technique is compared to most of the mainstream leakage reduction techniques by implementing them on ISCAS89 benchmark circuits. The proposed leakage reduction technique proved to be more effective in reducing gate leakage current than subthreshold leakage current. However, when combined with dual-threshold and variable-threshold CMOS techniques, substantial subthreshold leakage current reduction was also achieved. A total savings of 53% for subthreshold leakage current and 26% for gate leakage current are reported."--Abstract.

Covers in detail promising solutions at the device, circuit, and architecture levels of abstraction after first explaining the sensitivity of the various MOS leakage sources to these conditions from the first principles. Also treated are the resulting effects so the reader understands the effectiveness of leakage power reduction solutions under these different conditions. Case studies supply real-world examples that reap the benefits of leakage power reduction solutions as the book highlights different device design choices that exist to mitigate increases in the leakage components as technology scales.

Power consumption of VLSI (Very Large Scale Integrated) circuits has been growing at an alarmingly rapid rate. This increase in power consumption, coupled with the increasing demand for portable/hand-held electronics, has made power consumption a dominant concern in the design of VLSI circuits today. Traditionally, dynamic (switching) power has dominated the total power consumption of an IC. However, due to current scaling trends, leakage power has now become a major component of the total power consumption in VLSI circuits. Leakage power reduction is especially important in portable/hand-held electronics such as cell-phones and PDAs. This book presents two techniques aimed at reducing leakage power in digital VLSI ICs. The first technique reduces leakage through the selective use of high threshold voltage sleep transistors. The second technique reduces leakage by applying the optimal Reverse Body Bias (RBB) voltage. This book also shows readers how to turn the leakage problem into an opportunity, through the use of sub-threshold logic.

The book provides a comprehensive coverage of different aspects of low power circuit synthesis at various levels of design hierarchy; starting from the layout level to the system level. For a seamless understanding of the subject, basics of MOS circuits has been introduced at transistor, gate and circuit level; followed by various low-power design methodologies, such as supply voltage scaling, switched capacitance minimization techniques and leakage power minimization approaches. The content of this book will prove useful to students, researchers, as well as practicing engineers.

The authors present readers with a compelling, one-stop, advanced system perspective on the intrinsic issues of digital system design. This invaluable reference prepares readers to meet the emerging challenges of the device and circuit issues associated with deep submicron technology. It incorporates future trends with practical, contemporary methodologies.

CD-ROM contains: AIM SPICE (from AIM Software) -- Micro-Cap 6 (from Spectrum Software) -- Silos III Verilog Simulator (from Simucad) -- Adobe Acrobat Reader 4.0 (from Adobe).