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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Design and Measurement of StrongARM Comparators

Whitehead, Nathan Robert 29 October 2019 (has links)
The StrongARM comparator is utilized in many analog-to-digital converters (ADCs) because of its high power efficiency and rail-to-rail outputs. The performance of the comparator directly affects the speed, power, and accuracy of an ADC. However, the StrongARM comparator performance parameters such as delay, noise, and offset measured directly from silicon prototypes are rare in literature and often consist of small sample sets. In addition, existing techniques to measure the comparator require large chip areas, making it impractical to characterize a large number of comparators to obtain stochastic parameters such as offset and noise. This work presents novel circuit techniques to measure a large number of comparators (4,000) in a compact chip area to directly obtain silicon data including delay, noise, offset, and power. The proposed techniques also relax the requirement on the test instruments to measure the small time values. Four comparators with different transistor size ratios have been designed and measured to study the performance tradeoffs. In addition, this work presents a method utilizing supercomputing resources to simulate the large design space of the StrongARM comparator to observe the performance trends. Measurements are compared to simulations showing their accuracy and, for the first time, detailed study on the performance trends with different transistor size ratios.
42

Ownership in passive and active movements : A systematic review and meta-analysis of the moving rubber hand illusion

Arntz, Joakim January 2021 (has links)
The rubber hand illusion is an experimental paradigm that induces the illusion of ownership over a fake hand. The illusion was originally induced using visuotactile stimulation but can also be induced using movements. Self-produced movements are active movements, and if they are produced by external force, they are passive movements. According to the comparator model, only active movements produce a sense of agency. As both passive and active movements can be used to induce the sense of ownership in the rubber hand illusion, but only active induce a sense of agency, they can be compared to determine the effect agency has on bodily ownership. This meta-analysis included nine studies with a total of 359 participants that compared the induced sense of ownership using active and passive movements in the rubber hand illusion to determine these effects. The results show that agency has a small but significant effect on body ownership.
43

Design of a 5-bit algorithmic A/D converter for potential use in a wireless neural recorder application

Ranjan, Nikhil 04 June 2019 (has links)
The constant endeavor to measure and record neural signals from the human brain and anticipate the results to figure out the mechanism which governs the functionality of our brain and its true behavior is the major driving force behind this thesis. Neural recording integrated circuits (ICs) are often inserted directly into the brain, with a set of probes for sensing these action potentials (and local field potentials), and appropriate circuitry for amplifying the neural signals (Pre-Amp), sampling and converting the analog signals to digital (ADC) and transmitting the resulting digital signal (Transmitter) to a nearby reader instrument (Receiver). Action potentials are comprised of signals typically looking like spikes having a peak voltage of 1-2mV, whereas local field potentials are continuous signals generally having an amplitude of around 100-200μV often with a dc component of several mV. Fourier analysis of action potentials and local field potentials show frequency components in the range of 0.1 Hz up to 10kHz. This thesis proposes a low-power 5-bit algorithmic A/D converter to feed a 5-stage serial shift register for use in sampling and converting a presumed neuron action potential signal at the rate of 20k samples/sec. In addition to that, a low-power preamp with at least 40dB gain and a low-pass type spectrum having a unity-gain frequency of at least 20MHz is used to amplify the input signal. The algorithmic A/D converter includes a sample-and-hold circuit for sampling the analog action potential spike at a rate of 20kHz. The ADC utilizes an X2 gain circuit based on a capacitive redistribution technique. A less complex circuit in terms of dependency on Capacitor sizing and their non-ideal effects is the key factor for selecting this type of ADC which can be used for neural recording applications. All the circuits are designed based on the IBM/Global Foundries 8HP 130nm BiCMOS technology.
44

A Report on the Statistical Properties of the Coefficient of Variation and Some Applications

Irvin, Howard P. 01 May 1970 (has links)
Examples from four disciplines were used to introduce the coefficient of variation which was considered to have considerable usage and application in solving Quality Control and Reliability problems. The statistical properties were found in the statistical literature and are presented, namely, the mean and the variance of the coefficient of variation. The cumulative probability function was determined by two approximate methods and by using the noncentral t distribution. A graphical method to determine approximate confidence intervals and a method to determine if the coefficients of variation from two samples were significantly different from each other are also provided (with examples). Applications of the coefficient of variation to solving some of the main problems encountered in industry that are included in this report are: (a) using the coefficient of variation to measure relative efficiency, (b) acceptance sampling, (c) stress versus strength reliability problem, and (d) estimating the shape parameter of the two parameter Weibull. (84 pages)
45

ASIC implemented MicroBlaze-based Coprocessor for Data Stream Management Systems

Balasubramanian, Linknath Surya 05 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The drastic increase in Internet usage demands the need for processing data in real time with higher efficiency than ever before. Symbiote Coprocessor Unit (SCU), developed by Dr. Pranav Vaidya, is a hardware accelerator which has potential of providing data processing speedup of up to 150x compared with traditional data stream processors. However, SCU implementation is very complex, fixed, and uses an outdated host interface, which limits future improvement. Mr. Tareq S. Alqaisi, an MSECE graduate from IUPUI worked on curbing these limitations. In his architecture, he used a Xilinx MicroBlaze microcontroller to reduce the complexity of SCU along with few other modifications. The objective of this study is to make SCU suitable for mass production while reducing its power consumption and delay. To accomplish this, the execution unit of SCU has been implemented in application specific integrated circuit and modules such as ACG/OCG, sequential comparator, and D-word multiplier/divider are integrated into the design. Furthermore, techniques such as operand isolation, buffer insertion, cell swapping, and cell resizing are also integrated into the system. As a result, the new design attains 67.9435 µW of dynamic power as compared to 74.0012 µW before power optimization along with a small increase in static power, 39.47 ns of clock period as opposed to 52.26 ns before time optimization.
46

Design and Implementation of an analog to digital conversion mechanism for an in-situ monitoring microelectrode SOC

Alla, Ravi Chandar January 2008 (has links)
No description available.
47

Design and Evaluation of an Ultra-Low Power Successive Approximation ADC

Zhang, Dai January 2009 (has links)
<p>Analog-to-digital converters (ADC) targeted for use in medical implant devices serve an important role as the interface between analog signal and digital processing system. Usually, low power consumption is required for a long battery lifetime. In such application which requires low power consumption and moderate speed and resolution, one of the most prevalently used ADC architectures is the successive approximation register (SAR) ADC.This thesis presents a design of an ultra-low power 9-bit SAR ADC in 0.13μm CMOS technology. Based on a literature review of SAR ADC design, the proposed SAR ADC combines a capacitive DAC with S/H circuit, uses a binary-weighted capacitor array for the DAC and utilizes a dynamic latch comparator. Evaluation results show that at a supply voltage of 1.2V and an output rate of 1kS/s, the SAR ADC performs a total power consumption of 103nW and a signal-to-noise-and-distortion ratio of 54.4dB. Proper performance is achieved down to a supply voltage of 0.45V, with a power consumption of 16nW.</p>
48

Design and Evaluation of an Ultra-Low Power Successive Approximation ADC

Zhang, Dai January 2009 (has links)
Analog-to-digital converters (ADC) targeted for use in medical implant devices serve an important role as the interface between analog signal and digital processing system. Usually, low power consumption is required for a long battery lifetime. In such application which requires low power consumption and moderate speed and resolution, one of the most prevalently used ADC architectures is the successive approximation register (SAR) ADC.This thesis presents a design of an ultra-low power 9-bit SAR ADC in 0.13μm CMOS technology. Based on a literature review of SAR ADC design, the proposed SAR ADC combines a capacitive DAC with S/H circuit, uses a binary-weighted capacitor array for the DAC and utilizes a dynamic latch comparator. Evaluation results show that at a supply voltage of 1.2V and an output rate of 1kS/s, the SAR ADC performs a total power consumption of 103nW and a signal-to-noise-and-distortion ratio of 54.4dB. Proper performance is achieved down to a supply voltage of 0.45V, with a power consumption of 16nW.
49

Study on Zero-Crossing-Based ADCs for Smart Dust Applications

Khan, Shehryar, Awan, Muhammad Asfandyar January 2011 (has links)
The smart dust concept is a fairly recent phenomenon to engineering. It assumes monitoring of a real natural environment in which motes or smart dust machines swarm in collective and coordinate information among themselves and/or to a backend control platform. In analog mixed signal field work on such devices is gaining momentum such that it is conceived to be one of the emerging fields in technology, and work was only possible once the technology for fabrication touched the nanoscale regions. Smart dust network involves remote devices connected in a hive sensing burst type datum signals from the environment and relaying information amongst themselves in an energy efficient manner to coordinate an appropriate response to a detected stimulus. The project presumed a RF based communication strategy for coordination amongst the devices through a wireless medium. That is less susceptible to stringent requirements of LOS and a base band processing system that comprised of an environment sensor, an AFE module, an ADC, a DSP and a DAC. Essentially a 10 bit, 2 Mega Hertz MHz pipelined ADC implemented in a STM 65nm technology. The ADC benefits the smart dust device in allowing it to process data in an energy efficient way and also focusing on reduced complexity as itsdesign feature. While it differs in the other ADC of the system by operating at a higher frequency and assuming a different design philosophy assuming a coherent system sensitive to a clock. The thesis work assumes that various features ofenergy harvesting, regulation and power management present in the smart dustmote would enable the system to contain such a diverse ADC. The ADCs output digital datum would be compatible to the rest of the design modules consisting mainly of DSP sections. The ADC novelty is based on the fact that it removes the necessity of employing a high power consuming OpAmp whose design parameters become more complex as technology scales to the nanoscale era and further down. A systematic, bottom up, test driven approach to design is utilized and various behaviours of the system are captured in Cadence design environment with verilogto layout models and MATLAB and Simulink models.
50

A Cyclic Analog to Digital Converter for CMOS image sensors

Levski Dimitrov, Deyan January 2014 (has links)
The constant strive for improvement of digital video capturing speeds together with power efficiency increase, has lead to tremendous research activities in the image sensor readout field during the past decade. The improvement of lithography and solid-state technologies provide the possibility of manufacturing higher resolution image sensors. A double resolution size-up, leads to a quadruple readout speed requirement, if the same capturing frame rate is to be maintained. The speed requirements of conventional serial readout techniques follow the same curve and are becoming more challenging to design, thus employing parallelism in the readout schemes appears to be inevitable for relaxing the analog readout circuits and keeping the same capturing speeds. This transfer however imposes additional demands to parallel ADC designs, mainly related to achievable accuracy, area and power. In this work a 12-bit Cyclic ADC (CADC) aimed for column-parallel readout implementation in CMOS image sensors is presented. The aim of the conducted study is to cover multiple CADC sub-component architectures and provide an analysis onto the latter to a mid-level of depth. A few various Multiplying DAC (MDAC) structures have been re-examined and a preliminary redundant signed-digit CADC design based on a 1.5-bit modified flip-over MDAC has been conducted. Three comparator architectures have been explored and a dynamic interpolative Sub-ADC is presented. Finally, some weak spots degrading the performance of the carried-out design have been analyzed. As an architectural improvement possibility two MDAC capacitor mismatch error reduction techniques have been presented.

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