Statistics for Spatial Data.

Power dissipation is a fundamental problem for nanoelectronic circuits. Scaling the supply voltage reduces the energy needed for switching, but the field-effect transistors (FETs) in today's integrated circuits require at least 60 mV of gate voltage to increase the current by one order of magnitude at room temperature. Tunnel FETs avoid this limit by using quantum-mechanical band-to-band tunnelling, rather than thermal injection, to inject charge carriers into the device channel. Tunnel FETs based on ultrathin semiconducting films or nanowires could achieve a 100-fold power reduction over complementary metal-oxide-semiconductor (CMOS) transistors, so integrating tunnel FETs with CMOS technology could improve low-power integrated circuits.

Tunnel field-effect transistors as energy-efficient electronic switches

High leakage current in deep-submicrometer regimes is becoming a significant contributor to power dissipation of CMOS circuits as threshold voltage, channel length, and gate oxide thickness are reduced. Consequently, the identification and modeling of different leakage components is very important for estimation and reduction of leakage power, especially for low-power applications. This paper reviews various transistor intrinsic leakage mechanisms, including weak inversion, drain-induced barrier lowering, gate-induced drain leakage, and gate oxide tunneling. Channel engineering techniques including retrograde well and halo doping are explained as means to manage short-channel effects for continuous scaling of CMOS devices. Finally, the paper explores different circuit techniques to reduce the leakage power consumption.

Leakage current mechanisms and leakage reduction techniques in deep-submicrometer CMOS circuits

This ebook is the first authorized digital version of Kernighan and Ritchie's 1988 classic, The C Programming Language (2nd Ed.). One of the best-selling programming books published in the last fifty years, "K&R" has been called everything from the "bible" to "a landmark in computer science" and it has influenced generations of programmers. Available now for all leading ebook platforms, this concise and beautifully written text is a "must-have" reference for every serious programmers digital library.

As modestly described by the authors in the Preface to the First Edition, this "is not an introductory programming manual; it assumes some familiarity with basic programming concepts like variables, assignment statements, loops, and functions. Nonetheless, a novice programmer should be able to read along and pick up the language, although access to a more knowledgeable colleague will help."

The C programming language

As technology scales, variability in transistor performance continues to increase, making transistors less and less reliable. This creates several challenges in building reliable systems, from the unpredictability of delay to increasing leakage current. Finding solutions to these challenges require a concerted effort on the part of all the players in a system design. This article discusses these effects and proposes microarchitecture, circuit, and testing research that focuses on designing with many unreliable components (transistors) to yield reliable system designs.

Designing reliable systems from unreliable components: the challenges of transistor variability and degradation

Crosstalk analysis has become an essential part of high performance design in nanometer technologies. Interconnects in nanometer technology have increased resistance and coupling capacitance due to process scaling. The crosstalk pulses are complex and require a new modeling approach. We show that current models such as triangular and Weibull exhibit as much as 31% error in propagated pulse for some crosstalk waves in nanometer technology. We present a methodology based on wave fitting as a model for crosstalk waves. We compare the accuracy of the wave fitting model proposed with existing wave models such as: Weibull, isosceles triangular and trapezoidal. We present the simulation results for different gates in 65nm Bulk CMOS technology and provide a comparison in error statistics for propagated crosstalk pulse. We demonstrate that our approach has a average propagated pulse error of less than 5% and improves the overall crosstalk analysis results by at least 67%.

Crosstalk waveform modeling using wave fitting

An improved voltage reference generator is provided. The voltage reference generator comprises: a first transistor having a gate electrode biased to place the first transistor in a weak inversion mode; and a second transistor connected in series with said first transistor and having a gate electrode biased to place the second transistor in a weak inversion mode, where the threshold voltage of the first transistor is smaller than the threshold voltage of the second transistor and the gate electrode of the second transistor is electrically coupled to a drain electrode of the second transistor to form an output for a reference voltage.

Pico-power reference voltage generator

A duty-cycled bridge-to-digital converter (BDC) for small battery operated pressure sensing systems is presented and demonstrated in two complete microsystems. By heavily duty-cycling an excitation voltage for the bridge sensor, 6000× less excitation power is consumed compared with conventional DC biasing. The excitation voltage is sampled and used to generate an ADC reference voltage to avoid line voltage fluctuation. The BDC achieves 49.2 dB SNR and 2.5 nJ conversion energy with 10.6 pJ/c.s. FOM.

Low-Power Resistive Bridge Readout Circuit Integrated in Two Millimeter-Scale Pressure-Sensing Systems

Internet of Things (IoT) networks for smart sensor nodes in the next generation of smart wireless sensing systems require a distributed security scheme to prevent the passive (eavesdropping) or active (jamming and interference) attacks from untrusted sensor nodes. This paper concerns advancing the security of the IoT system to address their vulnerability to being attacked or compromised by the advancement of future supercomputers. In this work, a novel embedded architecture has been designed and implemented for a distributed IoT network that utilizes a master-slave full-duplex communication to exchange the random and continuous modulated phase shift as the secret key to be used in higher-layer encryptions.

Simultaneous Interference-Data Transmission for Secret Key Generation in Distributed IoT Sensor Networks.

Emerging loT applications, such as asset tracking and first-responder rescue operation, require a new localization solution that achieves decimeter-level accuracy for long range (km) in GPS-denied indoor non-line-of-sight (NLOS) scenarios. Impulse-response ultra-wideband radar (IR-UWB) [1]–[3] can achieve high precision, but cannot operate in long distance NLOS conditions due to FCC-regulated transmit-power limits and severe pathloss through walls. Moreover, IR-UWB requires very high instantaneous power (> 70mW [2]) rendering it impractical for energy-constrained loT with small batteries and high internal resistance. Lower-power solutions with narrower bandwidth, based on WiFi [4] or Bluetooth [5], typically have a limited range of < 100m or are not operable in NLOS. A proprietary 80MHz OFDM-based solution [6] using an active-reflection IC achieved decimeter-level accuracy in NLOS conditions. However, it requires relatively high power consumption (62.8mW) with a limited range up to ~100m. Addressing this technological gap, we propose a new crystal-less low-power RF receiver with -115dBm sensitivity for long-distance (up to 483m) ranging in NLOS conditions with decimeter-level (~0.6m) accuracy.

David Blaauw

Papers

Crosstalk waveform modeling using wave fitting

Pico-power reference voltage generator

Low-Power Resistive Bridge Readout Circuit Integrated in Two Millimeter-Scale Pressure-Sensing Systems

Simultaneous Interference-Data Transmission for Secret Key Generation in Distributed IoT Sensor Networks.

A Long-Range Narrowband RF Localization System with a Crystal-Less Frequency-Hopping Receiver