A 0.01%THD, 70dB PSRR Single Ended Class D using variable hysteresis control for headphone amplifiers

Switching audio amplifiers are widely used in HBridge topology thanks to their high efficiency; however low audio performances in single ended power stage topology is a strong weakness leading to not be used for headset applications. This paper explains the importance of efficient error correction in Single Ended Class-D audio amplifier. A hysteresis control for Class-D amplifier with a variable window is also presented. The analyses are verified by simulations and measurements. The proposed solution was fabricated in 0.13µm CMOS technology with an active area of 0.2mm2. It could be used in single ended output configuration fully compatible with common headset connectors. The proposed Class-D amplifier achieves a harmonic distortion of 0.01% and a power supply rejection of 70dB with a quite low static current consumption.

[1]  R. Adams,et al.  Integrated stereo ΔΣ class D amplifier , 2005, IEEE J. Solid State Circuits.

[2]  Simon S. Ang,et al.  A multi-loop voltage feedback filterless class-D switching audio amplifier using unipolar pulse-width-modulation , 2004, IEEE Transactions on Consumer Electronics.

[3]  Young-Hyun Jun,et al.  A 1.3-mW per-channel 103-dB SNR stereo audio DAC with class-D head-phones amplifier in 65nm CMOS , 2008, 2008 IEEE Symposium on VLSI Circuits.

[4]  Joseph Sylvester Chang,et al.  Bang–Bang Control Class-D Amplifiers: Power-Supply Noise , 2008, IEEE Transactions on Circuits and Systems II: Express Briefs.

[5]  R. Cellier,et al.  An integrated class D audio amplifier based on sliding mode control , 2008, 2008 IEEE International Conference on Integrated Circuit Design and Technology and Tutorial.

[6]  Michael A. E. Andersen,et al.  Hysteresis controller with constant switching frequency , 2005, IEEE Transactions on Consumer Electronics.

[7]  Joseph Sylvester Chang,et al.  Power Supply Noise in Bang-Bang Control Class D Amplifier , 2007, 2007 IEEE International Symposium on Circuits and Systems.

[8]  Pallab Midya,et al.  High Performance Digital Feedback for PWM Digital Audio Amplifiers , 2006 .

[9]  Meng Tong Tan,et al.  Design and analysis of a micropower low-voltage bang-bang control class D amplifier , 2005, 2005 IEEE International Symposium on Circuits and Systems.

[10]  Karsten Nielsen.  Linearity and Efficiency Performance of Switching Audio Power Amplifier Output Stages-A Fundamental Analysis , 1998 .

[11]  K. Sweetland,et al.  Integrated stereo /spl Delta//spl Sigma/ class D amplifier , 2005, IEEE Journal of Solid-State Circuits.

[12]  Edgar Sánchez-Sinencio,et al.  Design of a Class D Audio Amplifier IC Using Sliding Mode Control and Negative Feedback , 2007, IEEE Transactions on Consumer Electronics.

[13]  Ho-Young Lee,et al.  A 2W, 92% efficiency and 0.01% THD+N class-D audio power amplifier for mobile applications, based on the novel SCOM architecture , 2004, Proceedings of the IEEE 2004 Custom Integrated Circuits Conference (IEEE Cat. No.04CH37571).

[14]  Meng Tong Tan,et al.  Fourier Series Analysis for Nonlinearities Due to the Power Supply Noise in Open-Loop Class D Amplifiers , 2006, APCCAS 2006 - 2006 IEEE Asia Pacific Conference on Circuits and Systems.

[15]  Bah-Hwee Gwee,et al.  An investigation on the parameters affecting total harmonic distortion in class D amplifiers , 2000, 2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353).