Patent ID: 6377644
Filing Date: 2002-04-23
Classification: G01R

Abstract:
A method for determining the jitter of a periodic digital signal, including the steps of:defining a measurement period such that the ratio between the measurement period and the period of the digital signal is a ratio of integers, selecting a set of measurement periods in which the digital signal substantially has the same phase, defining a measurement time having a same position in each measurement period of the set, storing the value of the digital signal at each measurement time, shifting the measurement time by a predetermined pitch smaller than one measurement period; repeating the two preceding steps until the measurement time of each measurement period has scanned a predetermined portion of the measurement period in a vicinity of an edge of the digital signal, and comparing the stored values with an expected value, storing in a table the number of inequations resulting from these comparisons for each position of a measurement time, calculating the time derivative of the succession of numbers contained in this table, and using this derivative to calculate the jitter of the digital signal.