一种适用于高速高精度流水线ADC的放大器  

An Amplifier for High Speed High Accuracy Pipelined ADC

作　　者：黄显洋[1] 李树荣[1] 姚素英[1] 

机构地区：[1]天津大学电子信息工程学院,天津300072

出　　处：《电子学报》2006年第1期131-134,共4页Acta Electronica Sinica

摘　　要：本文提出了一种新颖的放大器结构.它由两部分组成:前面为跨导放大器,后面则是由电阻反馈形成的跨阻放大器,两种放大器的组合构成了具有高输入阻抗、低输出阻抗的电压放大器.与普通放大器不同的是,在我们设计的工作条件下,它输出端的极点几乎不受负载电容的影响.用该放大器作为预放大级,驱动一单级主放大器所构成的两级运放在负载电容为4pf的情况下实现了超过1GHz的增益带宽积,瞬态分析的结果表明它可以在10ns内达到0.01%的精度(闭环增益为8),而功耗仅有25mW,远低于同性能其他结构的放大器,非常适合作为高速高精度流水线模数转换器中的首级余量放大器使用.An amplifier with novel configuration is presented. It consists of two parts： a transconductance amplifier and a transresistance amplifier formed by resistor feedback. The combination of these two amplifier forms a voltage amplifier with low output impedance, and the pole at the output node is hardly affected by the loading capacitor. It is used as preamplifier to drive a single stage amplifier and thus a two stage operational amplifier is implemented. Simulation results show that more than 1GHz gain bandwidth product is achieved（4-pfload） with a power consumption of 25mW only. Transient simulation indicates a settling time of less than 10ns for 0.01% accuracy with a close loop gain of 8. This two stage operational amplifier is appropriate to be used in high speed high accuracy pipelined analog to digital converters.

关 键 词：放大器 增益带宽积 流水线模数转换器 

分 类 号：TN722[电子电信—电路与系统]