与工艺无关的Rail-to-RailCMOS运算放大器

A Robust Rail-to-Rail CMOS Operational Amplifier

设计了一种与工艺无关的 Rail- to- Rail运算放大器 ,它采用一种新型的与工艺无关的恒跨导 Rail- to- Rail输入级结构 ,输入级的 P管对和 N管对的宽长比不需匹配特定的工艺。同时 ,还采用了前馈 AB类控制的 rail- to- rail输出级 ,以保证输出级有大的动态输出范围和较强的驱动负载的能力。在电源电压为 2 .7V时 ,整个运算放大器在 0 .3 5μm Alcatel工艺和 0 .6μm无锡上华工艺下模拟 ,其输入级跨导偏差分别为 7%和 1 4%,直流增益分别为 87.9d B和 78.4d B,单位增益带宽分别为 1 4MHz和 9MHz,相位裕度为 6 7度和 75度。

A robust rail-to-rail operational amplifier is presented, in which a new robust constant g m rail-to-rail input stage is employed. This new circuit is robust in that it does not require transconductance parameter matching n- and p-channel transistors for specific technology. Meanwhile, a front-feed Class AB control is aslo developed to ensure large dynamic range and strong driving capability. The whole circuit is simulated in 0.35 μm Alcatel and 0.6 μm Wuxi-Shanghua technology at 2.7 V power supply, respectively. The circuits have achieved a maximum transconductance deviation less than 7 % and 14 %, DC gain of 87.9 dB and 78.4 dB, unit gain bandwidth of 14 MHz and 9 MHz,and a phase margin of 67° and 75°, respectively.