High efficiency class-I audio power amplifier using a single adaptive supply

A high efficiency class-1 linear audio power amplifier （PA） with an adaptive supply is presented. Its efficiency is improved by a dynamic supply to reduce the power transistors＇ voltage drop. A gain compression technique is adopted to make the amplifier accommodate a single positive supply. Circuit...

Full description

Saved in:
Bibliographic Details
Published in:Journal of semiconductors 2012-09, Vol.33 (9), p.95-101
Main Author: 彭振飞 杨姗姗 冯勇 刘洋 洪志良
Format: Article
Language:English
Subjects:
Amplifiers
Charge pumps
Electric potential
Electromagnetic interference
Nonlinearity
Power amplifiers
Semiconductors
Switching
功率晶体管
开关放大器
最大输出功率
线性放大器
自适应
负电源
非线性度
音频功率放大器
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A high efficiency class-1 linear audio power amplifier （PA） with an adaptive supply is presented. Its efficiency is improved by a dynamic supply to reduce the power transistors＇ voltage drop. A gain compression technique is adopted to make the amplifier accommodate a single positive supply. Circuit complicity and chip area are reduced because no charge pump is necessary for the negative supply. A common shared mode voltage and a symmetric layout pattern are used to minimize the non-linearity. A peak efficiency of 80% is reached at peak output power. The measured THD＋N before and after the supply switching point are 0.01% and 0.05%, respectively. The maximum output power is 410 mW for an 8 f2 speaker load. Unlike switching amplifiers, the class-I amplifier operates as a linear amplifier and hence has a low EMI. The advantage of a high efficiency and low EMI makes the class-1 amplifier suitable for portable and RF sensitive applications.
ISSN:1674-4926
DOI:10.1088/1674-4926/33/9/095002