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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
ABSTRACT Since 1910, Mexico has been a supplier and path for the migrating people, including Central Americans, in search of better living conditions. In fact, the flow of currencies from immigrants to their native country constitutes a lure for the dependent economic systems that they leave behind. During several migratory waves, men, particularly young ones, constituted the great migratory exodus. Beginning in the 1970s, women and children joined the waves of immigrants, and since 1994, the number of migrant children and adolescents has risen substantially. This latest immigration phenomenon is symbolized in the collection of short stories El oro del desierto (2005) by Cristina Pacheco (2005) and the documentaries Two Americans (2012) by Daniel DeVivo and Valeria Fernández and Sin país / Without Country (2011) by Theo Rigby, among others, where migrant subjects experience trauma, disappearance, and death. In addition to a sociohistorical context, these phenomena are revealed by the theoretical approaches in the works "The Intrusive Past: The Flexibility of Memory and the Engraving of Trauma" (1995) by Bessel A. van der Kolk, Unclaimed Experience: Trauma, Narrative, and History (1996) by Cathy Caruth, and Nomadic Subjects: Embodiment and Sexual Difference in Contemporary Feminist Theory (2011) by Rosi Braidotti. The reference work Diagnostic and Statistical Manual of Mental Disorders: Dsm-5. (2013) by the American Psychiatric Association was also helpful. Cited examples of literary and cinematographic representations show the psychological effects on children and adolescents migrants whose nomadic condition is shared with all human beings. To interpret this particular condition, we offer the history of immigration waves from Mexico and Central America into the United States and a psychological approach to interpret child and adolescent immigration experiences as presented in the literary and cinematic texts. Related to the migrant subjects, the selected texts highlight nomadism, traumatic event (including PTSD), and death. In addition, an identity emerges related to the nomadic subjects and those characters that live on the periphery and are framed by the hegemonic power.
ContributorsMuñoz, Aurora (Author) / Hernández-G, Manuel Jesús (Thesis advisor) / Rosales, Jesus (Thesis advisor) / Tompkins, Cynthia (Committee member) / Arizona State University (Publisher)
Created2014
Description
Reduced space is an important theme in the works of the Marquis de Sade including his epic novel The New Justine and his pornographic performance piece Philosophy in the Bedroom including the political/social treatise "Frenchmen, yet another effort is needed if you want to be a Republic". Through out his life Sade attempted to overcome reduction of space with writing. Tragically, his writing often prolonged the reduction of his space by sending him to or keeping him in prison. It is my theory that his violent, pornographic writing style is "une écriture de surjouissance" or "a writing of over-coming". Surjouissance is my theory for Sade's method, based on textual analysis of Sade's main works, that he combines through his syntactic structure, narrative voice, and semantic themes the orgasm of the mind represented by philosophical discourse with the orgasm of the body represented textually by orgiastic scenes and the language of orgasm to reach an ultimate state of complete freedom. In the political pamphlet "Frenchmen yet another effort..."Sade attempts to set this theory of sur-jouissance, or this transcendent state reached through the combination of physical and philosophical orgasm, as the political foundation for a new republic. Does he succeed in creating a viable political formula for a sustainable republic? My argument states absolutely not. His aristocratic elitism narrows his voice. But he does propose the combination of sexual, literary, and intellectual freedoms as a possible polemic against any form of reduced space.
ContributorsSwankie, Ryan James (Author) / Mullet, Isabelle (Thesis advisor) / Canovas, Frédéric (Committee member) / Bahtchevanova, Mariana (Committee member) / Arizona State University (Publisher)
Created2011
Description
This creative thesis is a work of narrative and lyric poetry. Death and Nature are two complex themes that emerge frequently in the poems and work as well across the breadth of the manuscript. The speakers' perspectives vary and are indebted to two sub-genres of poetry, namely--The Poetry of Witness, and Ekphrastic Poetry. Their psycho-analytic underpinnings are at times indisputable, and at other times, purely subjective. Many poems address political and human rights issues in the Middle East, and in the rest of the world. It is here that the poems depend and reveal flexibility with diction and varying structures. Overall, the poems reflect and investigate possible restraints and choices, both internally by the details and images, and externally by multiple experiments with free verse forms.
ContributorsHassan, Eman (Author) / Dubie, Norman (Thesis advisor) / Hogue, Cynthia (Committee member) / Savard, Jeannine (Committee member) / Arizona State University (Publisher)
Created2012
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 poems in To Name a Cat intend to capture certain abstractions—grief, love, betrayal, wonder, relativity, and, of course, expectation—in approachable anecdotes that, when brought together, create a narrative about loss that is, nevertheless, laced with hope. The work often relies on an animal, particularly the cat, as a vehicle to, and arbiter between the abstractions. Animals tend to illicit a certain innocence that is, perhaps, present in humans, but altogether tougher to find. Still, it is a noble errand to search, which is, at its heart, what To Name a Cat strives to do.
ContributorsConner, Reese (Author) / Ball, Sally (Thesis advisor) / Dubie, Norman (Committee member) / Rios, Alberto (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