Challenges and Solutions for Multi-Gigahertz Testing

The title of a paper presented at ITC in 1998 posed an interesting question: “High Speed TestingHave the laws of Physics finally caught up with us?” [1]. At say 10 GHz clock rates, the period is only 100ps and accurate testing may require control of logic transitions with picosecond accuracy. Indeed it seems as though we are quickly running out of spare picoseconds. The job of producing and measuring such signals is hard enough. Yet some of the toughest problems have to do with simply getting the signals to and from the device-under-test. Signal integrity and interfacing issues are usually critical to the success of a multigigahertz test. Add to these electrical performance challenges the ever-present pressure to reduce costs, and we have a problem that involves careful trade-offs between technical needs and economic demands.