Title: A Low THD Clock-Free Class-D Audio Amplifier with an Increased Damping Resistor and Cross Offset Cancellation Technique
Authors: Chou, Ying-Wei
Chien, Meng-Wei
Chen, Shin-Chieh
Chen, Ke-Horng
Lin, Ying-Hsi
Tsai, Tsung-Yen
Huang, Chen-Chih
Lee, Chao-Cheng
Tai, Zhih Han
Cheng, Yi Hsuan
Tsai, Chi Chung
Luo, Hsin-Yu
Wang, Shih-Ming
Chen, Long-Der
Yang, Cheng-Chen
Hui, Huang Tian
Institute of Electrical and Control Engineering
Keywords: self-oscillating;audio amplifier;Class-D audio amplifier;mobile application;offset cancellation;clock-free
Issue Date: 1-Jan-2014
Abstract: an increased damping resistor (IDR) replaces high-order loop filter to simply reduce the total harmonic distortion (THD) of Class-D audio amplifier. Besides, cross offset cancellation (COC) technique minimizes the system offset voltage to avoid dc current flows to the speaker in the bridge tied load (BTL) structure. Furthermore, variable switching frequency characteristic in self-oscillating modulation spreads the electro-magnetic interference (EMI) impact out on the output frequency spectrum. Experimental results demonstrate that the proposed Class-D amplifier can deliver 0.55W to the 8 Omega load with a 3.3V supply voltage with 150-nm CMOS process. The power efficiency is over 90% and the output THD is smaller than 0.01% (80dB).
URI: http://hdl.handle.net/11536/124910
ISBN: 978-1-4799-3432-4
ISSN: 0271-4302
Begin Page: 2680
End Page: 2683
Appears in Collections:Conferences Paper