【作者】 苏琴； 邓红辉； 尹勇生；

【Author】 Su Qin Deng Honghui Yin Yongsheng(Institute of VLSI Design,Hefei University of Technology Hefei 230009 China)

【机构】 合肥工业大学微电子设计研究所；

【摘要】 文章设计了一种低电压、恒定跨导、轨对轨的CMOS运算放大器。该运算放大器的差分输入级采用改进的电平移位方法实现了在轨对轨的共模输入范围内跨导的恒定;为了得到足够大的放大倍数,使用折叠式共源共栅结构作为前级放大;输出级采用AB类输出,扩大了输出摆幅,基本上达到满摆幅输出。用Cadence Hspice仿真器,基于SMIC 0.35 um模型仿真,该运算放大器的直流增益为90.1dB,相位裕度为59°,功耗为644uW。整个电路结构简单紧凑,输入输出线性动态范围宽,非常适合于低电压低功耗应用。更多还原

【Abstract】 A low voltage,constant transconductance,Rail-to-Rail,CMOS operational amplifier has been designed in this paper.It reaches to keep the total transconductor of the rail-to-rail common mode input stage constant,for it adopt a complementary input differential pairs which is controlled by an improved level shifter.In order to get enough gain,the folded-ascode structure is used as preamplifier.The Class-AB is used as the output stage,widen the output range,a rail-to-rail output range is achieved.I simulated the circuit using the Cadence Hspice based on SMIC 0.35um model.The simulation results shown that the dc gain of the operational amplifier is 90.1dB and which phase margin is 59°,it’s power dissipation is 644uW.For its structure is simple and compact,stable working and wider input-output linear dynamic range,this operational amplifier cell is suitable for low voltage low power dissipation application.更多还原