A Comparison of Phase-Shift Self- Oscillating and Carrier-based PWM Modulation for Embedded Audio Amplifiers
Huffenus , Alexandre
Pillonnet , Gaël
Abouchi , Nacer
Goutti , Frédéric
- Publisher: HAL CCSD
[ SPI ] Engineering Sciences [physics]
International audience; This paper compares two modulation schemes for Class-D amplifiers: Phase-Shift Self-Oscillating (PSSO) and Carrier-Based Pulse Width Modulation (PWM). Theoretical analysis (modulation, frequency of oscillation, bandwidth…), design procedure, and IC silicon evaluation will be shown for mono and stereo operation (on the same silicon die) on both structures. The design of both architectures will use as many identical building blocks as possible, to provide a fair, "all else being equal", comparison. THD+N performance and idle consumption went from 0.02% and 5.6mA in PWM to 0.007% and 5.2mA in Self-Oscillating. Other advantages and drawbacks of the Self-Oscillating structure will be explained and compared to the classical Carrier-Based PWM one, with a focus on battery-powered applications.