一种低压低功耗恒跨导轨到轨运算放大器设计  

Design of a rail-to-rail operational amplifier with constant transconductance under low-voltage and low-power

作　　者：谢海情[1] 陈玉辉 王振宇 XIE Haiqing;CHEN Yuhui;WANG Zhenyu(School of Physical and Electronic Sciences,Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学物理与电子科学学院,湖南长沙410114

出　　处：《电子元件与材料》2020年第10期65-69,共5页Electronic Components And Materials

基　　金：湖南省教育厅基金资助科研项目(17B007);长沙市科技计划重点项目(kq1901102)。

摘　　要：提出了一种恒跨导轨到轨运算放大器,输入级电路采用三倍电流镜结构,补偿输入差分对管的静态电流,降低输入级跨导变化率;中间级电路采用两个三层MOS管共源共栅结构代替传统轨到轨运算放大器中的四层MOS管套筒式共源共栅结构,实现四端输入转为双端输出,并降低电源电压;输出级电路采用交差耦合输出结构,实现轨到轨输出,同时完成双端输入转单端输出,设计一种恒跨导轨到轨运算放大器。基于TSMC 0.18μm工艺完成电路与版图设计,使用Spectre完成仿真。结果表明,在电源电压为1 V,输入电压从0 V变化到1 V时,该放大器可实现0~1 V的轨到轨输出,静态功耗仅为44μW,输入级跨导变化率为5.5%,实现了低电源电压、低功耗和恒跨导的性能指标。A rail-to-rail operational amplifier was designed with constant trans-conductance,which is operated at low-voltage and low-power.The input stage adopts a triple current mirror structure to compensate the static current of the input differential pair and reduce the trans-conductance variation.The intermediate stage adopts two three-layer cascade structures instead of traditional fourlayer structure.After that,the four input portals become two portals for the output,which reduced the power supply voltage.The output stage adopts a cross-coupled structure to realize rail-to-rail operation and differential-to-single ended conversion at the same time.The circuit and layout were designed with 0.18μm CMOS process and simulated by Spectre software.The result shows that the rail-to-rail input and output is realized at the power supply of 1 V.The static power consumption is 44μW.The input trans-conductance variation is smaller than 5.5%.This amplifier achieves low power supply voltage,low power consumption and constant transconductance.

关 键 词：运算放大器 恒跨导 轨到轨 低压低功耗 三倍电流镜 共源共栅 

分 类 号：TN43[电子电信—微电子学与固体电子学]