A 0.02% THD and 80 dB PSRR filterless class D amplifier with direct lithium battery hookup in mobile application  

作　　者：Hao Zheng Zhangming Zhu Rui Ma 

机构地区：[1]School of Microelectronics, Xidian University, Xi'an 710071, China [2]High-Tech Institute of Xi'an, Xi'an 710025, China

出　　处：《Journal of Semiconductors》2017年第7期56-63,共8页半导体学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.61234002,61322405,61306044)

摘　　要：This paper presents a fully integrated CMOS filterless class D amplifier that can directly hook up lithium battery in mobile application The proposed amplifier embodies a 2-order feedback path architecture instead of direct feedback of output to input of the integrator to decrease the high frequency intermodulation distortion associated with direct feedback and eliminate the integrator input common mode disturbance from the output in ternary modulation. The prototype class D amplifier realized in 0.35 μm digital technology achieves a THD＋N of 0.02% when delivering 400 m W to an 8 Ω load from V_（DD） =3.6 V. The PSRR of the prototype class D amplifier is 80 dB at217 Hz. Furthermore a filterless method that can eliminate the external LC filter is employed which offers great advantages of saving PCB space and lowering system cost. In addition the prototype class D amplifier can operate in large voltage range with V_（DD）range from 2.5 to 4.2V in mobile application. The total area of the amplifier is 1.7mm^2.This paper presents a fully integrated CMOS filterless class D amplifier that can directly hook up lithium battery in mobile application The proposed amplifier embodies a 2-order feedback path architecture instead of direct feedback of output to input of the integrator to decrease the high frequency intermodulation distortion associated with direct feedback and eliminate the integrator input common mode disturbance from the output in ternary modulation. The prototype class D amplifier realized in 0.35 μm digital technology achieves a THD＋N of 0.02% when delivering 400 m W to an 8 Ω load from V_（DD） =3.6 V. The PSRR of the prototype class D amplifier is 80 dB at217 Hz. Furthermore a filterless method that can eliminate the external LC filter is employed which offers great advantages of saving PCB space and lowering system cost. In addition the prototype class D amplifier can operate in large voltage range with V_（DD）range from 2.5 to 4.2V in mobile application. The total area of the amplifier is 1.7mm^2.

关 键 词：class D amplifier filterless THD feedback loop PWM 

分 类 号：TN722[电子电信—电路与系统]