一种宽频带大摆幅的三级CMOS功率放大器  

With large-bandwidth and large-swing three-stage power amplifier of CMOS

作　　者：刘三清[1] 张诗娟[1] 余岳辉[1] 陈晓飞[1] 

机构地区：[1]华中科技大学电子科学与技术系,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2005年第5期95-97,共3页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50277016).

摘　　要：设计了一种用于耳机驱动的CMOS功率放大器,该放大器采用0.35μm双层多晶硅工艺实现,驱动32Ω的电阻负载.该设计采用三级放大两级密勒补偿的电路结构,通过提高增益带宽来提高音频放大器的性能.仿真结果表明,该电路的开环直流增益为70dB,相位裕度达到86.6°,单位增益带宽为100MHz.输出级采用推挽式AB类结构,能有效地提高输出电压的摆幅,从而得到电路在低电源电压下的高驱动能力.结果表明,在3.3V电源电压下,电压输出摆幅为2.7V.A power amplifier of CMOS for headphone driver was designed and realized by using a 0.35?μm double-poly COMS technology. A tree-stage amplifier with double Miller compensation was used and the performance of audio power amplifier improved through increasing gain-bandwidth. According to the simulation, the dc gain of open loop is 70?dB and unity gain-bandwidth product of 100?MHz with 86.6° of phase margin can be achieved. The output swing can be improved efficiently with push-pull class-AB output stage, thus high-drive capability with low power supply is obtained. The result shows that the output swing is 2.7?V with 3.3?V single supply.

关 键 词：CMOS 功率放大器 单位增益带宽 输出摆幅 

分 类 号：TN722.1[电子电信—电路与系统]