基于传感器系统的低功耗运算放大器  

Low Power Operational Amplifier Based on Sensor System

作　　者：王健 钟问问 Wang Jian;Zhong Wenwen(College of Information Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China)

机构地区：[1]沈阳化工大学信息工程学院,沈阳110142

出　　处：《半导体技术》2023年第2期132-139,共8页Semiconductor Technology

摘　　要：为适应传感器系统向微型化发展的趋势,设计了一种低功耗运算放大器。放大器偏置电路以共源共栅电流镜结构为基础,输出稳定偏置电流;轨对轨输入级利用亚阈值技术,保证其跨导恒定;输出级采用电流镜结构,实现AB类工作;在求和电路和输出级之间添加电容电阻串联支路,对输出晶体管控制信号进行补偿。利用0.18μm工艺库对电路进行设计,在3 V电源电压、25℃条件下进行仿真,放大器低频增益为95 dB,单位增益带宽为6.15 kHz,输入失调电压小于45μV,在-40~85℃温度区间内,失调温漂为320 nV/℃,消耗功率始终低于2.28μW。目前该芯片已成功流片,实际测量芯片消耗功率为3.15μW。结果表明,该放大器能够满足传感器系统所要求的低功耗目标。In order to adapt to the development trend of sensor system to miniaturization,a low power operational amplifier was designed.The amplifier bias circuit was based on the structure of the cascode current mirror,which output stable bias current.The rail-to-rail input stage used subthreshold technology to ensure its constant transconductance.The output stage adopted current mirror structure for class AB operation.A capacitor resistance series branch was added between the sum circuit and the output stage to compensate the control signal of the output transistor.The circuit was designed by using 0.18μm process library and simulated under the conditions of 3 V power supply voltage and 25℃.The low frequency gain of the amplifier is 95 dB,the unit gain bandwidth is 6.15 kHz,the input offset voltage is less than 45μV,the offset temperature drift is 320 nV/℃in the temperature range of-40-85℃,and the power consumption is always less than 2.28μW.At present,the chip has successfully been fabricated,and the actual power consumption of the chip is 3.15μW.The results show that the amplifier can meet the requirement of low power consumption of sensor system.

关 键 词：传感器 低功耗 轨对轨 亚阈值技术 失调电压 

分 类 号：TN722.77[电子电信—电路与系统] TN433