Predicting Statistical Characteristics of Jitter Due to Simultaneous Switching Noise

Abstract

Switching of logic gates is often responsible for significant power supply noise. Predicting the jitter resulting from the power supply noise can be critical to analyze the proper operation of high-speed devices. The statistical characteristics of jitter, such as the mean standard deviation of jitter, can be used to place a meaningful bound on the worst-case timing margin and to estimate the bit error rate. While the statistical characteristics of the noise can be found through simulations of many input logic vectors, such simulations require significant computational effort and require methods for choosing suitable data vectors. Vectorless methods allow rapid analysis of switching without using predefined input data and can be used to understand which portions of the logic circuit contribute most to the noise. In this paper, methods using vectorless techniques are presented to predict the mean and standard deviation of the power supply noise on the printed circuit board (PCB), and the mean and standard deviation of the resulting peak-to-peak jitter in a driver on the same PCB. In experiments, the techniques were able to predict the average and standard deviation of the peak power supply noise on the PCB with 2% and 8% error, respectively, and of the peak-to-peak jitter with 21% error, which is sufficient for predicting how a specific logic design might impact jitter, and for proposing means to minimize that impact.