A 121.4-dB DR Capacitively Coupled Chopper Class-D Audio Amplifier

Huajun Zhang, Marco Berkhout, Kofi A.A. Makinwa, Qinwen Fan*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

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This article presents a class-D amplifier (CDA) with high dynamic range (DR). To eliminate the typically dominant noise contribution of a resistive feedback network, the input and feedback signals are chopped and applied to a capacitive feedback network. However, this leads to high-voltage (HV) transients at the input of the loop filter, which, due to timing and impedance mismatch in the chopped feedback network, could degrade linearity and even overstress low-voltage (LV) core devices. Robust processing of the HV chopped feedback signal is guaranteed with chopper timing skew correction, chopper impedance matching, and deadbanding. The prototype, implemented in a 180-nm bipolar-CMOS-DMOS (BCD) process, achieves 121.4 dB of DR, 5.9 dB higher than state-of-the-art closed-loop CDAs, and 8-μVRMS output-referred noise (A-weighted). It also achieves a peak total harmonic distortion (THD) + N of -109.8 dB and a peak efficiency of 93%/88% while driving 15 W/26 W into an 8-4-Ω load.

Original languageEnglish
Pages (from-to)3736-3745
Number of pages10
JournalIEEE Journal of Solid-State Circuits
Issue number12
Publication statusPublished - 2022

Bibliographical note

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care
Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.


  • Audio power amplifier
  • capacitively coupled chopper amplifier
  • class-D amplifier (CDA)
  • dynamic range (DR)
  • noise

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