Title :
A 650mW filterless class-D audio power amplifier for mobile applications in 65-nm technology
Author :
Pilloud, Bernard ; Groeneweg, Willem H.
Author_Institution :
Cellular Syst. Div., ST-NXP Wireless, Zurich, Switzerland
Abstract :
A class-D audio power amplifier in a standard 65-nm CMOS technology is designed for direct battery hook-up in a mobile phone. Special circuit techniques are used to overcome the voltage limitations of standard devices for operation at battery voltage levels of 2.7 - 4.8 V. The amplifier is based on a PWM modulator with feedback and outputs a three-level pulse width modulated power signal that eliminates the external low-pass filter and reduces the system cost. The amplifier achieves a power efficiency of 84% while delivering an output power of 650 mW with 1% THD into 8 Omega from a 3.7 V power supply.
Keywords :
CMOS integrated circuits; audio-frequency amplifiers; mobile handsets; power amplifiers; CMOS technology; PWM modulator; class-D audio power amplifier; mobile phones; power 650 mW; size 65 nm; voltage 2.7 V to 4.8 V; Batteries; CMOS technology; Feedback circuits; Mobile handsets; Operational amplifiers; Power amplifiers; Power filters; Pulse amplifiers; Pulse width modulation; Voltage;
Conference_Titel :
Circuits and Systems, 2009. ISCAS 2009. IEEE International Symposium on
Conference_Location :
Taipei
Print_ISBN :
978-1-4244-3827-3
Electronic_ISBN :
978-1-4244-3828-0
DOI :
10.1109/ISCAS.2009.5117970
