All-Digital Audio Amplifier

The approach presented in these pages processes the audio information digitally and generates a two-level pulse-width modulation (PWM) signal that is amplified by a switching power stage and finally low-pass filtered before it is sent to a speaker. The purpose of the digital signal processing (DSP) portion of the system is to transform the original audio information into a feasible, low-level PWM signal, with minimum possible degradation. The digital audio information is first upsampled, then converted from uniform to natural sampling to minimize distortion, and finally noise shaped to reduce the time resolution needed by the PWM edges without compromising the signal-to-noise (SNR) ratio. A PWM generator converts samples into pulses, and a switching stage creates a high-power replica of the PWM signal. Switching minimizes energy losses and introduces minimum extra degradation. The output low-pass filter extracts the audio information from the PWM signal and delivers it to the speaker. Each of the functional blocks required by this approach has been justified, implemented, and evaluated.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Pascual, Cesar

Contributors dc:contributor

• Krein, Philip T.

• Engineering, Electronics and Electrical

Language dc:language

eng

Identifier

(MiAaPQ)AAI9996671

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/81371