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ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


A dual-channel directional digital hearing aid (DHA) front end using Micro Electro Mechanical System (MEMS) microphones and an adaptive-power analog processing signal chain is presented. The analog front end consists of a double differential amplifier (DDA) based capacitance to voltage conversion circuit, 40dB variable gain amplifier (VGA) and a continuous time sigma delta analog to digital converter (CT - ΣΔ ADC). Adaptive power scaling of the 4th order CT - ΣΔ achieves 68dB SNR at 120μW, which can be scaled down to 61dB SNR at 67μW. This power saving will increse the battery life of the DHA. Dissertation/Thesis

Contributors
Deligoz, Ilker, Kiaei, Sayfe, Bakkaloglu, Bertan, et al.
Created Date
2010

A dual-channel directional digital hearing aid (DHA) front-end using a fully differential difference amplifier (FDDA) based Microphone interface circuit (MIC) for a capacitive Micro Electro Mechanical Systems (MEMS) microphones and an adaptive-power analog font end (AFE) is presented. The Microphone interface circuit based on FDDA converts the capacitance variations into voltage signal, achieves a noise of 32 dB SPL (sound pressure level) and an SNR of 72 dB, additionally it also performs single to differential conversion allowing for fully differential analog signal chain. The analog front-end consists of 40dB VGA and a power scalable continuous time sigma delta ADC, with …

Contributors
Naqvi, Syed Roomi, Kiaei, Sayfe, Bakkaloglu, Bertan, et al.
Created Date
2011

Power supply management is important for MEMS (Micro-Electro-Mechanical-Systems) bio-sensing and chemical sensing applications. The dissertation focuses on discussion of accessibility to different power sources and supply tuning in sensing applications. First, the dissertation presents a high efficiency DC-DC converter for a miniaturized Microbial Fuel Cell (MFC). The miniaturized MFC produces up to approximately 10µW with an output voltage of 0.4-0.7V. Such a low voltage, which is also load dependent, prevents the MFC to directly drive low power electronics. A PFM (Pulse Frequency Modulation) type DC-DC converter in DCM (Discontinuous Conduction Mode) is developed to address the challenges and provides a …

Contributors
Zhang, Xu, Chae, Junseok, Kiaei, Sayfe, et al.
Created Date
2012