標題: A 94% Efficiency Near-Constant Frequency Self-Oscillating Class-D Audio Amplifier with Voltage Control Resistor
作者: Ng, Shao Siang
Lin, Kuei-Liang
Chen, Ke-Horng
Chen, Yu-Wen
電控工程研究所
Institute of Electrical and Control Engineering
關鍵字: self-oscillating audio amplifier;class-D;frequency stable technique;SoC system
公開日期: 2013
摘要: A self-oscillating constant frequency class-D audio amplifier with voltage control resistor (VCR) technique is proposed for system-on-a-chip (SoC) applications. The VCR control circuit is used to ensure stable switching frequency over a wide range of the modulation index. The proposed method also improves the THD performance at high output power condition. The proposed self-oscillating class-D amplifier can have extremely good performance since the carrier distortion is avoided and the intrinsic harmonic can be attenuated by the second-order loop filter. The VCR control can dynamically adjust the switching frequency according to distinct modulation index. In addition, stable frequency operation can reduce the switching frequency at low output amplitude to improve power efficiency. Experimental results demonstrate that the proposed class-D amplifier can delivers 1.4W to the 8 Omega load with a 5V supply. The power efficiency is achieved over 95% and the output THD can be smaller than 0.001%.
URI: http://hdl.handle.net/11536/24133
ISBN: 978-1-4673-5762-3; 978-1-4673-5760-9
ISSN: 0271-4302
期刊: 2013 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS)
起始頁: 602
結束頁: 605
Appears in Collections:Conferences Paper