高性能Rail-to-Rail恒定跨导CMOS运算放大器  

High-Performance Rail-to-Rail Constant-gm CMOS Operational Amplifier

作　　者：张强[1] 李攀[1] 田泽[1] 陈贵灿[2] 刘宁[1] 

机构地区：[1]西北大学信息学院,陕西西安710127 [2]西安交通大学微电子研究所,陕西西安710049

出　　处：《微电子学与计算机》2008年第3期166-171,共6页Microelectronics & Computer

基　　金：陕西省科技攻关项目(2004k05-G11);美国应用材料创新基金项目(ZX05097-XA-AM-200514)

摘　　要：基于UMC的0.6μm BCD 2P2M工艺,探讨了一种高性能Rail-to-Rail恒定跨导CMOS运算放大器.该运算放大器的输入级采用互补差分对,其尾电流由共模输入信号来控制,以此来保证输入级的总跨导在整个共模范围内保持恒定.输出级采用ClassAB类控制电路,并且将其嵌入到求和电路中,以此减少控制电路电流源引起的噪声和失调.为了优化运算放大器低频增益、频率补偿、功耗及谐波失真,求和电路采用了浮动电流源来偏置.该运算放大器采用米勒补偿实现了18MHz的带宽,低频增益约为110dB,Rail-to-Rail引起的跨导变化约为15%,功耗约为10mW.A high-performance rail-to-rail corkstant gm operational amplifier is presented with UMC 0.6 μm BCD2P2M processes. The input stage consists of an NMOS and a PMOS differential pair connected in parallel, the tail current of input stage are controlled by common mode signal, in this way, the total gm of input stage is maintained as a constant arange the whole ICM. The output stage employs a classAB control circuit, and this part is shifted into the current summation to prevent the ClassAB control circuit contributm to noise and offer. IN order to optimize the low frequency gain, frequency compensation, power dissipation and reduce the harmonic distortion of the amplifer, a floating current source is employed to biases the current summation circuit. This amplifer achieved a 18MHz bandwidth with Miller compensation. The low frequency gain is about 110dB, the gm variation is about 15% from Rail-to-Rail. The power dissipation of the amplifer is about 10mW.

关 键 词：Rail—to-Rail 恒定跨导 浮动电流源 CMOS运算放大器 

分 类 号：TN432[电子电信—微电子学与固体电子学]