NBTI机制下运算放大器的性能退化分析及其可靠性设计

Analysis of Operational Amplifier Performance Degradation under NBTI Mechanisim and Its Reliable Design

随着CMOS器件尺寸的不断缩小,集成电路设计阶段的可靠性问题变得愈加重要,NBTI效应作为重要的可靠性问题之一得到了大量的研究,并从电路级对其提出了改进。采用等效电路模型表征NBTI退化对模拟电路的影响,研究了两级运算放大器在NBTI效应影响下电路参数的退化,分析并确定了影响传统两级运算放大器性能的关键器件。在此基础上,对传统运放结构进行改进,引入反馈,使-3 d B带宽的退化量由27%降到了1%左右,从而减小NBTI退化对电路性能的影响。

With the scaling-down of CMOS device,reliability become increasingly significant in the stage of integrat-edcircuit design.NBTI effect has received lots of researches as one of the key reliability problems,and some improve-ment methods has been put forward from the circuit level.Afailure-equivalent model for NBTI degradation on the cir-cuit has been proposed.Degradation affected by NBTI of two-stage operational amplifierhas beenstudied,we analyze and identify the key components of the traditional two-stage operational amplifier. Based on this,the structure of the conventional operational amplifier is improved by the introduction of feedback. The degradation of-3 dB bandwidth is optimized from 27%to about 1%,thereby the NBTI effect on conventional operational amplifier is reduced.