Title :
Circuit techniques to overcome Class-D audio amplifier limitations in mobile devices
Author :
Jiang, Xicheng ; Song, Jungwoo ; Wang, Minsheng ; Chen, Jianlong ; Arunachalam, Sasi Kumar ; Brooks, Todd L.
Author_Institution :
Broadcom Corp., Irvine, CA, USA
Abstract :
Circuit techniques to overcome practical noise, reliability, and EMI limitations are reported. An auxiliary loop with ramping circuits suppresses pop-and-click noise to 1 mV for an amplifier with 4V achievable output voltage. Switching edge rate control enables the system to meet the EN55022 Class-B standard with a 15 dB margin. An enhanced scheme detects short-circuit conditions without relying on over-limit current events.
Keywords :
audio-frequency amplifiers; electromagnetic interference; mobile handsets; noise; reliability; EMI limitation; EN55022 class-B standard; auxiliary loop; circuit technique; class-D audio amplifier limitation; mobile device; noise figure 15 dB; over-limit current event; pop-and-click noise; practical noise; ramping circuit; reliability; short-circuit condition; switching edge rate control; voltage 1 mV to 4 V; Electromagnetic interference; Image edge detection; Noise; Pulse width modulation; Resistors; Standards; Switches;
Conference_Titel :
VLSI Circuits (VLSIC), 2012 Symposium on
Conference_Location :
Honolulu, HI
Print_ISBN :
978-1-4673-0848-9
Electronic_ISBN :
978-1-4673-0845-8
DOI :
10.1109/VLSIC.2012.6243768
