V. Rabary

Publications (2)0 Total impact

• Conference Proceeding: Improved Class-K amplifier for headset applications

  E. Sturtzer, G. Pillonnet, A. Huffenus, N. Abouchi, F. Goutti, V. Rabary
  [show abstract] [hide abstract]
  ABSTRACT: This paper proposes an improved Class-K audio amplifier as an alternative solution to Class-AB and Class-G audio amplifiers for Headset applications. The Class-K architecture consists in a linear and a switching amplifier connected in parallel to the same speaker. The advantage of this solution is to associate the power efficiency of the switching amplifier with the linearity of a linear amplifier. However, the Class-K may suffer from static consumption. Three methods are presented in order to compensate the topology's disadvantages: a ternary modulation, a two-stage linear amplifier and a low idle switching amplifier. In this paper, we present the Class-K operating principle, a topological comparison and solutions to improve high static consumption. The simulation results prove the validity of these solutions, achieving less than 2mA of static current.
  NEWCAS Conference (NEWCAS), 2010 8th IEEE International; 07/2010
• Conference Proceeding: A phase-shift self-oscillating stereo class-D amplifier for battery-powered applications

  A. Huffenus, G. Pillonnet, N. Abouchi, F. Goutti, V. Rabary, C. Specq
  [show abstract] [hide abstract]
  ABSTRACT: This paper presents a highly efficient stereo audio amplifier, based on a self-oscillating modulator. This modulation scheme has been analyzed and shows to have a higher bandwidth and error correction than standard Pulse Width Modulation (PWM). A practical implementation in CMOS 0.25um technology has been done to validate our theoretical and simulation results, based on a modified PWM amplifier. Our amplifier demonstrated a Total Harmonic Distortion plus Noise (THD+N) as low as 0.007%, current consumption is 3.88mA at 3.6V (stereo) and the efficiency reaches 88% into 8Ohms. The integrated circuit measures 1.6×1.6mm and is able to work at supply voltages from 2.3V to 5.5V.
  Circuits and Systems (ISCAS), Proceedings of 2010 IEEE International Symposium on; 07/2010