Novel crosstalk evaluation method for high-density signal traces using clock waveform conversion technique

Abstract

Today, as LSI devices are increasingly more integrated resulting in larger number of package pins, high speed signal lines are more easily coupled to each other. Additionally, since multisite testing is required to reduce the cost of test, the transmission lines connecting these pins become even more concentrated. To measure these LSI devices, a huge number of high-speed transmission lines are required in the test board. Therefore minimizing crosstalk is very important. Furthermore, since the number of channels have reached more than ten thousand in recent evaluation systems, it is strongly required that the crosstalk from all channels be measured. With so many channels, measuring crosstalk with traditional methods will at best be very time-consuming or at worse, completely impractical, as it requires either a large number of pulse generators or physical reconnections depending on measurement type. In this paper, we propose a very fast and low cost crosstalk measurement method, which can acquire results very quickly and with high frequency resolution. Only a single measurement makes it possible to evaluate the crosstalk over a wide frequency band without the repetition of manually measuring at each frequency. This method is highly beneficial to the automatic test equipment (ATE) environment with high density transmission lines on the performance boards or load boards.