Title :
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
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;
Conference_Titel :
VLSI Design and Video Technology, 2005. Proceedings of 2005 IEEE International Workshop on
Print_ISBN :
0-7803-9005-9
DOI :
10.1109/IWVDVT.2005.1504557
