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- Genre: Masters Thesis
- Creators: Arizona State University
- Creators: Chakraborty, Bijeta
- Creators: Peterson, Cory
- Member of: ASU Electronic Theses and Dissertations
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
Baruch de Spinoza (1632-1677) is most often treated as a secular philosopher in the literature. But the critical-historical and textual analyses explored in this study suggest that Spinoza wrote the Ethics not as a secular project intended to supersede monotheism for those stoic enough to plumb its icy depths, but rather, and as is much less often assumed, as a genuinely Judeo-Christian theological discourse accounting for the changing scientific worldviews and political realities of his time. This paper draws upon scholarship documenting Spinoza's involvement with Christian sects such as the Collegiants and Quakers. After establishing the largely unappreciated importance of Spinoza's religious or theological thought, a close reading of the Ethics demonstrates that friendship is the theme that ties together Spinoza's ethical, theological, political, and scientific doctrines.
ContributorsBelcheff, David (Author) / Samuelson, Norbert (Thesis advisor) / Clay, Eugene (Thesis advisor) / Foley, Peter (Committee member) / Arizona State University (Publisher)
Created2014
Description
Frederic Thrasher's early work with youth gangs in Chicago continues to influence contemporary gang research. Thrasher's basic premise, that conflict with outside groups facilitates strong interpersonal ties between adolescents, has yet to undergo quantitative analysis. Using data from Wave II of the National Longitudinal Study of Adolescent Health ("Add Health"), this conflict is measured by the aggregate number of juvenile arrests for property and violent crimes in a community. Multivariate regression is conducted to explore the impact of police threat on number of friendship nominations, while logistic regression is conducted to see if police threat is impacting relationship strength between respondent's first male and female friend. The results from both the multivariate and logistic regressions do not support Thrasher's hypothesis. Implications for future research are discussed.
ContributorsMoule, Richard K (Author) / Katz, Charles M. (Thesis advisor) / Ready, Justin T. (Committee member) / Pratt, Travis C. (Committee member) / Arizona State University (Publisher)
Created2011
Description
Class D Amplifiers are widely used in portable systems such as mobile phones to achieve high efficiency. The demands of portable electronics for low power consumption to extend battery life and reduce heat dissipation mandate efficient, high-performance audio amplifiers. The high efficiency of Class D amplifiers (CDAs) makes them particularly attractive for portable applications. The Digital class D amplifier is an interesting solution to increase the efficiency of embedded systems. However, this solution is not good enough in terms of PWM stage linearity and power supply rejection. An efficient control is needed to correct the error sources in order to get a high fidelity sound quality in the whole audio range of frequencies. A fundamental analysis on various error sources due to non idealities in the power stage have been discussed here with key focus on Power supply perturbations driving the Power stage of a Class D Audio Amplifier. Two types of closed loop Digital Class D architecture for PSRR improvement have been proposed and modeled. Double sided uniform sampling modulation has been used. One of the architecture uses feedback around the power stage and the second architecture uses feedback into digital domain. Simulation & experimental results confirm that the closed loop PSRR & PS-IMD improve by around 30-40 dB and 25 dB respectively.
ContributorsChakraborty, Bijeta (Author) / Bakkaloglu, Bertan (Thesis advisor) / Garrity, Douglas (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
The term “friend zone” has been used in various areas of social media and pop culture to define a situation where one individual covets a relationship with a close friend that never evolves; typically the situation includes a male seeking a potential romantic partner with a female. Although friendship is often viewed in a positive format and sometimes the foundation of a healthy relationship, this term has been stigmatized as an unfortunate situation and counterproductive to obtaining a fulfilling relationship.
To approach the multi-faceted concern of friend zone phenomena and the many areas damaging messages that occur, my thesis starts with the history of friend zone phenomena, establishing a definition of friend zone phenomena for future scholars. Next literature on friendship and love, and Galician’s work used for both the methodology and theoretical framework is introduced leading to the analysis. The methodology and theoretical framework for the analysis uses Mary-Lou Galician’s 7-Step-Reality-Check-Up, twelve Myths social media promoted as the preferred reading and the Twelve Prescriptions (Rxs) for Getting Real About Romance. Resources on the discourses of gender performativity, psychology, and sociology are also included in the theoretical framework.
I start with an introduction to retrograde misogyny, The Manosphere (including The Red Pill [TRP]), the Elliot Rodger case and rape culture. This initial segment is analyzed differently from the other texts to describe the crux of social justice issues within friend zone phenomena. I then analyze 10 online memes related to friend zone phenomena. Lastly, I analyze Jet and Star’s new book, How to Get out of the Friend Zone –their book is a textual version of the advice they give on their YouTube channel.
Throughout all the texts Myths 5 (Physical Attraction), 6 (Man = Stronger), and 13 (No Cross-Sexual Friends) were all proposed as the preferred reading. Myth 14 (Men Want Sex/Women Want Money) was prevalent across the memes and TRP/Rational Male. All four myths are laden with gender performativity with damaging perceptions of healthy and respectful relationships. Additional research on friend zone phenomena in the form of interviews and surveys is recommended as research is still sparse.
To approach the multi-faceted concern of friend zone phenomena and the many areas damaging messages that occur, my thesis starts with the history of friend zone phenomena, establishing a definition of friend zone phenomena for future scholars. Next literature on friendship and love, and Galician’s work used for both the methodology and theoretical framework is introduced leading to the analysis. The methodology and theoretical framework for the analysis uses Mary-Lou Galician’s 7-Step-Reality-Check-Up, twelve Myths social media promoted as the preferred reading and the Twelve Prescriptions (Rxs) for Getting Real About Romance. Resources on the discourses of gender performativity, psychology, and sociology are also included in the theoretical framework.
I start with an introduction to retrograde misogyny, The Manosphere (including The Red Pill [TRP]), the Elliot Rodger case and rape culture. This initial segment is analyzed differently from the other texts to describe the crux of social justice issues within friend zone phenomena. I then analyze 10 online memes related to friend zone phenomena. Lastly, I analyze Jet and Star’s new book, How to Get out of the Friend Zone –their book is a textual version of the advice they give on their YouTube channel.
Throughout all the texts Myths 5 (Physical Attraction), 6 (Man = Stronger), and 13 (No Cross-Sexual Friends) were all proposed as the preferred reading. Myth 14 (Men Want Sex/Women Want Money) was prevalent across the memes and TRP/Rational Male. All four myths are laden with gender performativity with damaging perceptions of healthy and respectful relationships. Additional research on friend zone phenomena in the form of interviews and surveys is recommended as research is still sparse.
ContributorsMichael, Cherish Krista (Author) / Elenes, C. Alejandra (Thesis advisor) / Hall, Deborah (Committee member) / Murphy-Erfani, Julie (Committee member) / Arizona State University (Publisher)
Created2015
Description
In this thesis, a digital input class D audio amplifier system which has the ability
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
to reject the power supply noise and nonlinearly of the output stage is presented. The main digital class D feed-forward path is using the fully-digital sigma-delta PWM open loop topology. Feedback loop is used to suppress the power supply noise and harmonic distortions. The design is using global foundry 0.18um technology.
Based on simulation, the power supply rejection at 200Hz is about -49dB with
81dB dynamic range and -70dB THD+N. The full scale output power can reach as high as 27mW and still keep minimum -68dB THD+N. The system efficiency at full scale is about 82%.
ContributorsBai, Jing (Author) / Bakkaloglu, Bertan (Thesis advisor) / Arizona State University (Publisher)
Created2015