Audio power amplifier using in cellular phone with improved PSRR

Author

Jianlong, Li ; Quanyuan, Feng

Author_Institution

Inst. of Microelectron., Southwest Jiaotong Univ., Chengdu, China

fYear

2005

fDate

28-30 May 2005

Firstpage

87

Lastpage

89

Abstract

A fully differential folded-cascode op-amp is applied into the audio power amplifier successfully. PSRR (power supply rejection ratio) of whole chip is higher than 60 dB between 20 Hz and 20 kHz, especially 82 dB at 217 Hz. Analysis and simulation has shown that PSRR of both op-amp and whole chip are improved. As a result, improved PSRR reduces the effect of noise on power supply lines being picked up and intensified by the audio power amplifier using cellular phone. The chip is manufactured by CSMC 0.6μm, 3.3 V/5 V, 2P2M, CMOS process.

Keywords

audio-frequency amplifiers; cellular radio; circuit noise; mobile handsets; operational amplifiers; power amplifiers; radiofrequency amplifiers; 0.6 mum; 217 Hz; 3.3 V; 5 V; 82 dB; CMOS process; audio power amplifier; cellular phone; differential folded-cascode operational amplifier; noise reduction; power supply lines; power supply rejection ratio; Analytical models; Cellular phones; Circuits; Differential amplifiers; Frequency; High power amplifiers; Noise reduction; Operational amplifiers; Power amplifiers; Power supplies;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Design and Video Technology, 2005. Proceedings of 2005 IEEE International Workshop on

Print_ISBN

0-7803-9005-9

Type

conf

DOI

10.1109/IWVDVT.2005.1504557

Filename

1504557