High Power Audio Amplifier with Variable Power Supply

• Main Authors: Yu-Chen Chang, 張佑丞
• Other Authors: Huang-Jen Chiu
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/u285tg

博士 === 國立臺灣科技大學 === 電子工程系 === 105 === Conventional audio power amplifiers are operating with fixed power supply. It means that the power losses caused by quiescent current are also fixed and regardless to output power. When power amplifier working in low power condition, the voltage across power devices will be larger than high power condition such that the losses on power devices increase. This dissertation presents an audio power amplifier with variable power supply controlled by input audio signal. In low-power output condition, the power supply will provide low voltage to reduce the power loss on power transistors and improve circuit efficiency. The power supply voltage of power amplifier can be controlled by the audio input signal used as the reference of power converter. The amplifier system is divided into two parts: the audio power amplifier adopting an integrated amplifier driving circuit with class AB topology and the power supply implemented with a full-bridge phase-shifted converter.