Fig. 1.
Typical architecture of a true digital class-D amplifier.
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| Citation: |
Shumeng Luo, Dongmei Li. A digital input class-D audio amplifier with sixth-order PWM[J]. Journal of Semiconductors, 2013, 34(11): 115001. doi: 10.1088/1674-4926/34/11/115001
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S M Luo, D M Li. A digital input class-D audio amplifier with sixth-order PWM[J]. J. Semicond., 2013, 34(11): 115001. doi: 10.1088/1674-4926/34/11/115001.
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A digital input class-D audio amplifier with sixth-order PWM
DOI: 10.1088/1674-4926/34/11/115001
More Information
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Abstract
A digital input class-D audio amplifier with a sixth-order pulse-width modulation (PWM) modulator is presented. This modulator moves the PWM generator into the closed sigma-delta modulator loop. The noise and distortions generated at the PWM generator module are suppressed by the high gain of the forward loop of the sigma-delta modulator. Therefore, at the output of the modulator, a very clean PWM signal is acquired for driving the power stage of the class-D amplifier. A sixth-order modulator is designed to balance the performance and the system clock speed. Fabricated in standard 0.18 μm CMOS technology, this class-D amplifier achieves 110 dB dynamic range, 100 dB signal-to-noise rate, and 0.0056% total harmonic distortion plus noise.-
Keywords:
- PWM,
- class-D digital audio,
- sigma-delta
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References
[1] Minsheng W, Xicheng J, Jungwoo S, et al. A 120 dB dynamic range 400 mW class-D speaker driver with fourth-order PWM modulator. IEEE J Solid-State Circuits, 2010, 45(8):1427 doi: 10.1109/JSSC.2010.2047426[2] Guanziroli F, Bassoli R, Crippa C, et al. A 1 W 104 dB SNR filter-less fully-digital open-loop class D audio amplifier with EMI reduction. IEEE J Solid-State Circuits, 2012, 47(3):686 doi: 10.1109/JSSC.2011.2178930[3] Lee Y H, Seok C K, Kim B J, et al. A 1.3 mW per-channel 103-dB SNR stereo audio DAC with class-D head-phones amplifier in 65 nm CMOS. IEEE Symposium on VLSI Circuits, 2008 http://ieeexplore.ieee.org/document/4585996/[4] Berkhout M, Dooper L. A 3.4 W digital-in class-D audio amplifier. Proceedings of the ESSCIRC, 2011[5] Ramaswamy S, Krishnan J, Forejt B, et al. A high-performance digital-input class-D amplifier with direct battery connection in a 90nm digital CMOS process. Digest of Technical Papers, IEEE International Solid-State Circuits Conference, 2008:436 http://ieeexplore.ieee.org/document/4523244/[6] Teplechuk M A, Gribben T, Amadi C. True filterless class-D audio amplifier. IEEE J Solid-State Circuits, 2011, 46(12):2784 doi: 10.1109/JSSC.2011.2162913[7] Gaalaas E, Liu B Y, Nishimura N. Integrated stereo delta-sigma class D amplifier. Digest of Technical Papers, IEEE International Solid-State Circuits Conference, 2005:120 http://ieeexplore.ieee.org/document/1493898/[8] Goldberg J M, Sandler M B. New high accuracy pulse width modulation based digital-to-analogue convertor/power amplifier. IEE Proceedings Circuits, Devices and Systems, 1994, 141(4):315 doi: 10.1049/ip-cds:19941102[9] Nielsen K, Olufsen B, Denmark. A review and comparison of pulse width modulation (PWM) methods for analog and digital input switching power amplifiers. AES E-Library, 1997, 102:4446 http://www.aes.org/e-lib/browse.cfm?elib=7333[10] Berkhout M, Dooper L. Class-D audio amplifiers in mobile applications. IEEE Trans Circuits Syst Ⅰ:Regular Papers, 2010, 57(5):992 doi: 10.1109/TCSI.2010.2046200[11] Berkhout M. An integrated 200-W class-D audio amplifier. IEEE J Solid-State Circuits, 2003, 38(7):1198 doi: 10.1109/JSSC.2003.813238 -
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