A second-order class-D audio amplifier
Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to t...
| Main Authors: | , , |
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| Format: | Article |
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SIAM
2011
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| Online Access: | https://eprints.nottingham.ac.uk/1888/ |
| _version_ | 1848790680151785472 |
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| author | Cox, Stephen M. Tan, M.T. Yu, J. |
| author_facet | Cox, Stephen M. Tan, M.T. Yu, J. |
| author_sort | Cox, Stephen M. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to the audio signal. A mathematical model is developed here for a second-order class-D amplifier design (i.e., containing one second-order integrator) with negative feedback. We derive exact expressions for the dominant distortion terms, corresponding to a general audio input signal, and confirm these predictions with simulations. We also show how the observed phenomenon of “pulse skipping” arises from an instability of the analytical solution upon which the distortion calculations are based, and we provide predictions of the circumstances under which pulse skipping will take place, based on a stability analysis. These predictions are confirmed by simulations. |
| first_indexed | 2025-11-14T18:16:28Z |
| format | Article |
| id | nottingham-1888 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T18:16:28Z |
| publishDate | 2011 |
| publisher | SIAM |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-18882020-05-04T20:23:48Z https://eprints.nottingham.ac.uk/1888/ A second-order class-D audio amplifier Cox, Stephen M. Tan, M.T. Yu, J. Class-D audio amplifiers are particularly efficient, and this efficiency has led to their ubiquity in a wide range of modern electronic appliances. Their output takes the form of a high-frequency square wave whose duty cycle (ratio of on-time to off-time) is modulated at low frequency according to the audio signal. A mathematical model is developed here for a second-order class-D amplifier design (i.e., containing one second-order integrator) with negative feedback. We derive exact expressions for the dominant distortion terms, corresponding to a general audio input signal, and confirm these predictions with simulations. We also show how the observed phenomenon of “pulse skipping” arises from an instability of the analytical solution upon which the distortion calculations are based, and we provide predictions of the circumstances under which pulse skipping will take place, based on a stability analysis. These predictions are confirmed by simulations. SIAM 2011 Article PeerReviewed Cox, Stephen M., Tan, M.T. and Yu, J. (2011) A second-order class-D audio amplifier. SIAM Journal on Applied Mathematics, 71 (1). pp. 270-287. ISSN 0036-1399 http://dx.doi.org/10.1137/100788367 doi:10.1137/100788367 doi:10.1137/100788367 |
| spellingShingle | Cox, Stephen M. Tan, M.T. Yu, J. A second-order class-D audio amplifier |
| title | A second-order class-D audio amplifier |
| title_full | A second-order class-D audio amplifier |
| title_fullStr | A second-order class-D audio amplifier |
| title_full_unstemmed | A second-order class-D audio amplifier |
| title_short | A second-order class-D audio amplifier |
| title_sort | second-order class-d audio amplifier |
| url | https://eprints.nottingham.ac.uk/1888/ https://eprints.nottingham.ac.uk/1888/ https://eprints.nottingham.ac.uk/1888/ |