为了满足低电压低功耗的应用需求,本文利用MOSFET在亚阈区的超低功耗特性,实现了一种带共模反馈的亚阈运算放大器.该亚阈运算放大器结构简单,采用TSMC 0.18μm工艺实现,且工作于1.2 V电源电压下.通过Synopsys Hspice仿真,结果表明,该电路在输出负载为0.5pF时直流增益为70.97 dB、单位增益带宽6.346 MHz、相位裕度85.76°、正负压摆率分别为3.58V/μs和-3.58 V/μs,功耗仅为4.80μW.
To meet the requirements of low-voltage and low-power,a sub-threshold operation amplifier(op-amp) with common-mode feedback is designed,using the ultra-low power feature of MOSFET which works in sub-threshold region.The subthreshold op-amp is implemented under TSMC 0.18 μm process with a single 1.2 V supply and simulated by Synopsys Hspice.The simulation results show that the subthreshold op-amp whth a 0.5 pF output load has a DC gain of 70.97 dB,a unity gain bandwidth of 6.346 MHz,a phase margin of 85.76°,positive and negative slew rate of 3.58 V/μs and-3.58 V/μs respectively,and its power consumption is only 4.80 μW.