用失效捕捉法测试AC参数

本文介绍了数字集成电路测试系统的工作原理,提出了两种AC参数的定量测试方法：二分步长测试和on the fly测试。通过预先设置驱动/比较时间和测试向量、执行功能测试、从结果存储器获取“通过/失效”结果,可以计算出AC参数的量值。测试一个AC参数,二分步长测试方法需多次执行测试向量,on the fly测试法仅需执行一次测试,但要求测试系统具备on the fly资源。两种方法的测试精度相同,均能有效解决AC参数的定量测试,后者更适于高速器件的测试。文中介绍的方法在BC3192集成电路测试系统上对MAX488器件进行测试,在250 kHz的测试频率下,两种方法测得的tSKEW参数结果近似相等,具有很好的一致性。

AC parameters test by failure capture methods

This paper introduces the principle of digital IC test system, and develops two quantitative methods to test AC parameters： step-dichotomy test and on the fly test. By presetting the driving/comparing time and vectors, then starting with the IC functional testing, the value of AC parameters can be figured through acquiring the PASS/FAIL results from the capture memory. It needs multi-executions of vectors to test an AC parameter by step-dichotomy test method, but only one execution by on the fly test, which requires test system with on the fly resources. They have the same test accuracy and can be an effective solution to AC quantitative test, and the later is more suitable for high-speed device test. The two methods have been applied to MAX488 in BC3192 IC test system with 250 kHz testing frequency, the test results of tSKEW parameter are approximately equal and have good consistency.