Matching Items (7)
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- Genre: Masters Thesis
- Creators: Arizona State University
- Creators: Chakraborty, Bijeta
- 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
This composition was commissioned by the Orgelpark to be performed in Amsterdam in September 2011 during Gaudeamus Muziekweek. It will be performed by the vocal group VocaalLab Nederland. It is scored for four vocalists, organ, tanpura, and electronic sound. The work is a culmination of my studies in South Indian Carnatic rhythm, North Indian classical singing, and American minimalism. It is a meditation on the idea that the drone and pulse are micro/macro aspects of the same phenomenon of vibration. Cycles are created on the macroscale through a mathematically defined scale of harmonic/pitch relationships. Cycles are created on the microscale through the subdivision and addition of rhythmic pulses.
ContributorsAdler, Jacob (Composer) / Rockmaker, Jody (Thesis advisor) / Feisst, Sabine (Committee member) / Etezady, Roshanne, 1973- (Committee member) / Arizona State University (Publisher)
Created2011
Description
In semiconductor physics, many properties or phenomena of materials can be brought to light through certain changes in the materials. Having a tool to define new material properties so as to highlight certain phenomena greatly increases the ability to understand that phenomena. The generalized Monte Carlo tool allows the user to do that by keeping every parameter used to define a material, within the non-parabolic band approximation, a variable in the control of the user. A material is defined by defining its valleys, energies, valley effective masses and their directions. The types of scattering to be included can also be chosen. The non-parabolic band structure model is used. With the deployment of the generalized Monte Carlo tool onto www.nanoHUB.org the tool will be available to users around the world. This makes it a very useful educational tool that can be incorporated into curriculums. The tool is integrated with Rappture, to allow user-friendly access of the tool. The user can freely define a material in an easy systematic way without having to worry about the coding involved. The output results are automatically graphed and since the code incorporates an analytic band structure model, it is relatively fast. The versatility of the tool has been investigated and has produced results closely matching the experimental values for some common materials. The tool has been uploaded onto www.nanoHUB.org by integrating it with the Rappture interface. By using Rappture as the user interface, one can easily make changes to the current parameter sets to obtain even more accurate results.
ContributorsHathwar, Raghuraj (Author) / Vasileska, Dragica (Thesis advisor) / Goodnick, Stephen M (Committee member) / Saraniti, Marco (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
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
Description
Patterns and Soundscapes explores the concept album format, popularized in the late 1960s and into modern times by artists such as the Who, Pink Floyd, and Frank Zappa. Specifically, I sought to adapt this format as a compositional process aimed towards the completion of a large-scale work that can be presented in album format and live performance. Further influenced by the concept album, I sought to create pieces consisting of similar musical techniques, motivic ideas, and harmonic language, so that each piece could be performed on its own or be combined as a multi-movement work.
I began writing this work in the spring of 2019, with “Colored Red Currents” for string quartet and “Conspiracy Wall” for two drum sets. After realizing that both pieces had a similar sound and style, I began to consider how they could function within an album format, and how they could also work together to form a large-scale musical work. I then decided that each subsequent piece, in addition to being composed of similar musical ideas, would be written in a manner that allowed for seamless transitions between the end of one and the beginning of another, and would also introduce the instrumentation making up the full ensemble in the last movement.
This work begins with the sparkling and rapid string quartet, “Colored Red Currents,” then moves to the energetic and groove based “Conspiracy Wall” for two drum sets, the meditative “Interlude” for solo viola and electronics, and the quick and mechanical “Beat Frequency” for alto saxophone, bass clarinet, and electronics. The work ends with “ALL IN,” where the full ensemble is finally formed, and all of the patterns and soundscapes come together to form a bombastic and wild finale.
I began writing this work in the spring of 2019, with “Colored Red Currents” for string quartet and “Conspiracy Wall” for two drum sets. After realizing that both pieces had a similar sound and style, I began to consider how they could function within an album format, and how they could also work together to form a large-scale musical work. I then decided that each subsequent piece, in addition to being composed of similar musical ideas, would be written in a manner that allowed for seamless transitions between the end of one and the beginning of another, and would also introduce the instrumentation making up the full ensemble in the last movement.
This work begins with the sparkling and rapid string quartet, “Colored Red Currents,” then moves to the energetic and groove based “Conspiracy Wall” for two drum sets, the meditative “Interlude” for solo viola and electronics, and the quick and mechanical “Beat Frequency” for alto saxophone, bass clarinet, and electronics. The work ends with “ALL IN,” where the full ensemble is finally formed, and all of the patterns and soundscapes come together to form a bombastic and wild finale.
ContributorsGrossman, Brendan Patrick (Author) / Rockmaker, Jody (Thesis advisor) / Norby, Christopher (Thesis advisor) / Bolanos, Gabriel (Committee member) / Arizona State University (Publisher)
Created2020
Description
This paper introduces an application space of Power over Ethernet to Universal Serial Bus (USB) Power Delivery, and develops 3 different flyback approaches to a 45 Watt solution in the space. The designs of Fixed Frequency Flyback, Quasi-Resonant Flyback, and Active Clamp Flyback are developed for the application with 37 Volts (V) to 57 V Direct Current (DC) input voltage and 5 V, 9 V, 15 V, and 20 V output, and results are examined for the given specifications. Implementation based concerns are addressed for each topology during the design process. The systems are proven and tested for efficiency, thermals, and output voltage ripple across the operation range. The topologies are then compared for a cost and benefit analysis and their highlights are identified to showcase each systems prowess.
ContributorsNasir, Anthony Michael (Author) / Ayyanar, Raja (Thesis advisor) / Lei, Qin (Committee member) / Hari, Ajay (Committee member) / Arizona State University (Publisher)
Created2021