International Science Index


Multi-Level Pulse Width Modulation to Boost the Power Efficiency of Switching Amplifiers for Analog Signals with Very High Crest Factor


The main goal of this paper is to develop a switching amplifier with optimized power efficiency for analog signals with a very high crest factor such as audio or DSL signals. Theoretical calculations show that a switching amplifier architecture based on multi-level pulse width modulation outperforms all other types of linear or switching amplifiers in that respect. Simulations on a 2 W multi-level switching audio amplifier, designed in a 50 V 0.35 mm IC technology, confirm its superior performance in terms of power efficiency. A real silicon implementation of this audio amplifier design is currently underway to provide experimental validation.

[1] A. R. Oliva, S. Ang, and T. V. Vo, “A multi-loop voltage-feedback filterless class-D switching audio amplifier using unipolar pulse-width-modulation,” IEEE Transactions on Consumer Electronics, vol. 50, no. 1, pp. 312-319, 2004.
[2] X. Jiang, “Fundamentals of audio class-D amplifier design: a review of schemes and architectures,” IEEE Solid-State Circuits Magazine, vol. 9, no. 3, pp. 14-25, 2017.
[3] V. De Gezelle, J. Doutreloigne, and A. Van Calster, “A 765mW high-voltage switching ADSL line-driver,” Solid-State Electronics, vol. 49, no. 12, pp. 1947-1950, 2005.
[4] H. Ertl, J. W. Kolar, and F. C. Zach, “Analysis of a multilevel multicell switch-mode power amplifier employing the “flying-battery” concept,” IEEE Transactions on Industrial Electronics, vol. 49, no. 4, pp. 816-823, 2002.
[5] J. Doutreloigne, “A new multi-level switching amplifier architecture with improved power efficiency,” Proceedings of the International Conference on Circuits and Systems (ICCS 2015) of the World Congress on Engineering and Computer Science (WCECS 2015), (San Francisco, USA), pp. 7-11, October 2015.
[6] J. Doutreloigne, H. De Smet, and A. Van Calster, “A versatile micropower high-voltage flat-panel display driver in a 100V 0.7m CMOS Intelligent Interface Technology,” IEEE Journal of Solid-State Circuits, vol. 36, no. 12, pp. 2039-2048, 2001.
[7] J. Doutreloigne, “A monolithic low-power high-voltage driver for bistable LCDs,” Microelectronics Journal, vol. 37, no. 11, pp. 1220-1230, 2006.