Design of a 3rd order 1.5-bit continuous-time fully differential sigma-delta (ƩΔ) modulator optimized for a class D audio amplifier using differential pairs

Nuno Pereira, João L. A. de Melo, Nuno Paulino

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

This paper presents a 3rd order 1.5-bit Continuous-Time Fully Differential ƩΔ modulator with distributed feedback for a class D audio amplifier, using BJT differential pairs to implement the integrator stages. By relying on simple gain blocks instead of operational amplifiers to build the loop filter, a simpler overall circuit is obtained, where the non-ideal effects are embedded in the loop filter transfer function. This leads to a more difficult design process for the loop filter circuit, solved through the use of an optimization procedure based on genetic algorithms. Simulations of the electrical circuit show that it is capable of achieving a SNDR value of 73.4 dB and THD+N of about -80 dB for a signal bandwidth of 20 kHz and a sampling frequency of 1.28 MHz.

Original languageEnglish
Title of host publicationTECHNOLOGICAL INNOVATION FOR THE INTERNET OF THINGS
EditorsL. M. Camarinha-Matos, S. Tomic, P. Graça
Place of PublicationBerlin, Heidelberg
PublisherSpringer-Verlag
Pages639-646
Number of pages8
ISBN (Electronic)978-3-642-37291-9
ISBN (Print)978-3-642-37290-2
DOIs
Publication statusPublished - 2013
Event4th IFIP WG 5.5/SOCOLNET Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2013 - Costa de Caparica, Portugal
Duration: 15 Apr 201317 Apr 2013

Publication series

NameIFIP Advances in Information and Communication Technology
PublisherSpringer-Verlag
Volume394
ISSN (Print)1868-4238

Conference

Conference4th IFIP WG 5.5/SOCOLNET Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2013
CountryPortugal
CityCosta de Caparica
Period15/04/1317/04/13

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Keywords

  • Audio
  • Class D Amplifier
  • Continuous-Time Sigma-Delta (ƩΔ)
  • Differential Pair

Cite this

Pereira, N., Melo, J. L. A. D., & Paulino, N. (2013). Design of a 3rd order 1.5-bit continuous-time fully differential sigma-delta (ƩΔ) modulator optimized for a class D audio amplifier using differential pairs. In L. M. Camarinha-Matos, S. Tomic, & P. Graça (Eds.), TECHNOLOGICAL INNOVATION FOR THE INTERNET OF THINGS (pp. 639-646). (IFIP Advances in Information and Communication Technology; Vol. 394). Berlin, Heidelberg: Springer-Verlag. https://doi.org/10.1007/978-3-642-37291-9_69