逻辑门电路电流测试方案的设计与应用

Design and Implementation of Current Test Scheme for Logic Gate Circuits

电流测试是逻辑门电路量产测试的重点和难点。为逻辑门电路设计了一套电流测试方案:一是构建了电流测量单元,探讨了输入缓冲电路、差分放大电路、抗混叠滤波器、偏置电路和模数转换电路等模块的协同机制;二是搭建了电流测量单元仿真模型,对直流输出、瞬态响应、输出噪声关键性能指标进行评估。以八位串入并出寄存器74HC595芯片为测试对象,对比了电流测试方案与商用自动测试设备(ATE)的静态电流、输入端口漏电流、输出驱动电流等参数,最大相对误差仅为3.26%,电流测试方案能够满足量产需求。有效解决了商用ATE在进行电流测试时资源利用不足的问题,可以在芯片生产过程中得到较好推广。

Current test is the key and difficult point of mass production test on logic gate circuits.A set of current test scheme was designed for the logic gate circuits:first,the current measurement unit was constructed,and the cooperation mechanism of modules such as input buffer circuit,differential amplifier circuit,anti-aliasing filter,bias circuit and A/D conversion circuit was discussed;secondly,the simulation model of current measurement unit was built to evaluate the key performance indexes such as DC output,transient response and output noise.Taking the 8-bit serial-in-parallel-out register 74HC595 chip as the test object,the current test scheme was compared with the static current,input port leakage current and output drive current of commercial Automatic Test Equipment(ATE).The maximum relative error is only 3.26%,so the current test scheme can meet the demand of mass production.Effectively solved is the problem of insufficient utilization of resources in current test of commercial ATE,which can be well promoted in the process of chip production.