Skip to main content

A 280 mW, 0.07% THD+N class-D audio amplifier using a frequency-domain quantizer

Analog Integrated Circuits and Signal Processing volume 72, pages 173–186 (2012)Cite this article

Abstract

Pulse density modulation (PDM) based class-D amplifiers can reduce non-linearity and tonal content due to carrier signal in pulse width modulation based amplifiers. However, their low-voltage analog implementations also require a linear loop filter and a quantizer. A PDM based class-D audio amplifier using a frequency-domain quantization is presented. The digital intensive frequency-domain approach achieves high linearity under low supply regimes. An analog comparator and a single-bit quantizer are replaced with a current controlled oscillator (ICO) based frequency discriminator. By using the ICO as a phase integrator, a third-order noise shaping is achieved using only two analog integrators. A single-loop, single-bit, class-D audio amplifier is presented with an H-bridge switching power stage, which is designed and fabricated on a 0.18 μm CMOS process with 6 layers of metal achieving a total harmonic distortion plus noise (THD+N) of 0.065% and a peak power efficiency of 80% while driving a 4-Ω loudspeaker load. The amplifier can deliver the output power of 280 mW.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

£ 29.95

Price includes VAT (United Kingdom)

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Fig. 21
Fig. 22
Fig. 23
Fig. 24
Fig. 25

References

  1. Pilloud, B., & Groeneweg, W. H. (2009) A 650 mW filterless class-D audio power amplifier for mobile applications in 65-nm technology. IEEE international symposium on circuits and systems (pp. 1173–1176), May 2009.

  2. Krabbenborg, B., & Berkhout, M. (2010). Closed-loop class-D amplifier with nonlinear loop integrators. IEEE Journal Solid-State Circuits, 45(7), 1389–1397.

    Article  Google Scholar 

  3. Shu, W., & Chang, J. S. (2008). THD of closed-loop analog PWM class-D amplifiers. IEEE Transactions on Circuits and Systems I, Regular Papers, 55(6), 1769–1777.

    Article  MathSciNet  Google Scholar 

  4. Yeh, M. L., Liou, W. R., Hsieh, H. P., & Lin, Y. J. (2010). An electromagnetic interference (EMI) reduced high-efficiency switching power amplifier. IEEE Transactions on Power Electronics, 25(3), 710–718.

    Article  Google Scholar 

  5. Adduci, P., Botti, E., Dallago, E., & Venchi, G. (2007). PWM power audio amplifier with voltage/current mixed feedback for high-efficiency speakers. IEEE Transactions on Industrial Electronics, 54(2), 1141–1149.

    Article  Google Scholar 

  6. Ertl, H., Kolar, J. W., & Zach, F. C. (1997). Basic considerations and topologies of switched-mode assisted linear power amplifiers. IEEE Transactions on Industrial Electronics, 44(1), 116–123.

    Article  Google Scholar 

  7. Gaalaas, E., Liu, B. Y., Nishimura, N., Adams, R., & Sweetland, K. (2005). Integrated stereo ΣΔ class D amplifier. IEEE Journal on Solid-State Circuits, 40(12), 2388–2397.

    Article  Google Scholar 

  8. Fujimoto, Y., Re, P. L., & Miyamoto, M. (2005). A delta-sigma modulator for a 1-bit digital switching amplifier. IEEE Journal on Solid-State Circuits, 40(9), 1865–1871.

    Article  Google Scholar 

  9. Lin, C. W., Lee, Y. P., & Chen, W. T. (2008). A 1.5 bit 5th order CT/DT delta sigma class D amplifier with power efficiency improvement. IEEE international symposium on circuits and systems (pp. 280–283), May 2008.

  10. Kang, K., Roh, J., Choi, Y., Roh, H., Nam, H., & Lee, S. (2008). Class-D audio amplifier using 1-bit fourth-order delta-sigma modulation. IEEE Transactions on Circuits and Systems II, 55(8), 728–732.

    Article  Google Scholar 

  11. Paramesh, J., & von Jouanne, A. (2001). Use of sigma-delta modulation to control EMI from switch-mode power supplies. IEEE Transactions on Industrial Electronics, 48(1), 111–117.

    Article  Google Scholar 

  12. Kim, J., & Cho, S. (2006). A time-based analog-to-digital converter using a multi-phase voltage-controlled oscillator. IEEE international symposium on circuits and systems (pp. 3934–3937), May 2006.

  13. Iwata, A., Sakimura, N., Nagata, M., & Morie, T. (1999). An architecture of delta sigma analog-to-digital converters using a voltage-controlled oscillator as a multi-bit quantizer. IEEE Transactions on Circuits and Systems II, 46(7), 941–945.

    Article  Google Scholar 

  14. Straayer, M. Z., & Perrott, M. H. (2008). A 12-bit, 10-MHz bandwidth, continuous-time ΣΔ ADC with a 5-bit, 950-MS/s VCO-based quantizer. IEEE Journal on Solid-State Circuits, 43(4), 805–814.

    Article  Google Scholar 

  15. Berkhout, M., & Dooper, L. (2010). Class-D audio amplifiers in mobile applications. IEEE Transactions on Circuits and Systems I, 57(5), 992–1002.

    Article  MathSciNet  Google Scholar 

  16. Park, M., & Perrott, M. H. (2009). A 78 dB SNDR 87 mW 20 MHz bandwidth continuous-time ΔΣ ADC with VCO-based integrator and quantizer implemented in 0.13 μm CMOS. IEEE Journal on Solid-State Circuits, 44(12), 3344–3358.

    Article  Google Scholar 

  17. Baird, R. T., & Fiez, T. S. (1994). Stability analysis of high-order delta-sigma modulation for ADC’s. IEEE Transactions on Circuits and Systems II, 41(1), 59–62.

    Article  Google Scholar 

  18. Ballan, H., & Declercq, M. (1995). 12 V Σ–Δ Class-D amplifier in 5 V CMOS technology. Proc. IEEE Custom Integrated Circuits Conf., paper 26.5 (pp. 559–562).

  19. Jeong, S.-G., & Park, M.-H. (1991). The analysis and compensation of dead time effects in PWM inverters. IEEE Transactions on Industrial Electronics, 38(2), 108–114.

    Article  MathSciNet  Google Scholar 

  20. Yavari, M., Shoaei, O., & Svelto, F. (2005). Hybrid cascode compensation for two-stage CMOS operational amplifiers. IEEE international symposium on circuits and systems (pp. 1565–1568), March 2005.

  21. Wisland, D. T., Hovin, M. E., & Lande, T. S. (2002). A novel multi-bit parallel ΔΣ FM-to-digital converter with 24-bit resolution. Proceedings of the 28th European solid-state circuits conference (pp. 687–690).

  22. Kwon, J., & Bakkaloglu, B. (2007). Impact of sampling clock phase noise on ΣΔ frequency discriminators. IEEE Transactions on Circuits and Systems II, 54(11), 949–953.

    Article  Google Scholar 

  23. NJU8721 class D headphone amplifier datasheet (2003). New Japan Radio Co. Ltd, August.

  24. Forejt, B., Rentala, V., Burra, G., & Arteaga, J. (2004). A 250 mW class D design with direct battery hookup in a 90 nm process. IEEE custom integrated circuits conference (pp. 169–172) Nov 2004.

  25. Li, S. C., Lin, V. C., Nandhasri, K., & Ngarmnil, J. (2005). New high-efficiency 2.5 V 0.45 W RWDM class-D audio amplifier for portable consumer electronics. IEEE Transactions on Circuits and Systems I, 52(9), 1767–1774.

    Article  Google Scholar 

  26. Ge, T., & Chang, J. S. (2008). Modeling and technique to improve PSRR and PS-IMD in analog PWM class-D amplifiers. IEEE Transactions on Circuits and Systems II, 55(6), 512–516.

    Article  Google Scholar 

  27. TPA2005D1 data sheet. Texas Instruments Incorporated.

  28. LM4861 data sheet. National Semiconductor Incorporated.

Download references

Author information

Authors and Affiliations

  1. Department of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, 85287, USA

    Junghan Lee, Tino Copani, Sayfe Kiaei & Bertan Bakkaloglu

  2. Texas Instruments Inc. High Volume Analog Group, Dallas, TX, 75243, USA

    Terry Mayhugh Jr. & Bhaskar Aravind

Authors
  1. Junghan Lee
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Tino Copani
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Terry Mayhugh Jr.
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Bhaskar Aravind
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Sayfe Kiaei
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Bertan Bakkaloglu
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Junghan Lee.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Lee, J., Copani, T., Mayhugh, T. et al. A 280 mW, 0.07% THD+N class-D audio amplifier using a frequency-domain quantizer. Analog Integr Circ Sig Process 72, 173–186 (2012). https://doi.org/10.1007/s10470-011-9813-4

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10470-011-9813-4

Keywords

  • Class-D amplifiers
  • Sigma-delta modulation
  • Audio amplifiers
  • Frequency discriminators