CMOS电路瞬态电流测试及其解析模型研究

Test and Analytical Model Research on Transient Current of CMOS Circuit

CMOS电路瞬态电流(IDDT)测试技术,在超高速高可靠芯片故障诊断领域有着良好的应用前景。由于芯片的集成度和工作速度越来越高,IDDT迅速增长,降低了其性能和可靠性,研究IDDT快速准确计算方法具有较强的应用需求。介绍了CMOS电路IDDT测试技术的发展及其基本原理和方法,深入分析了CMOS电路电流成份和特性,利用PSPICE及MOSFET仿真模型,建立了具有较高精度的瞬态电流解析模型。提出撬杠电流("crow-bar")相对于电容充电电流,在高速下不仅不小,甚至可能更大,在电流分析时不可忽略。

IDDT test of CMOS IC is a promising technique in fault diagnosis area of super high speed and high reliability IC. Transient current of CMOS circuit makes chip of CMOS circuit suffer from operation temperature increase, which may lower the circuit＇s performance and reliability. Thus it is very important to estimate the transient current quickly and accurately. The basic theory and development of IDDT test is introduced,the composing and characteristic of current of CMOS IC is analyzed,and an analytical model of transient current with high accuracy is built by using PSPICE and MOSFET simulation model. At high speed the＂ crowbar＂ part is not less than the capacitor charge part of transient current, the former may even bigger than the latter,so shouldnt ignore the＂crowbar＂current during current analysis.