Patent ID: 7480581

Claim:
A method of calibrating automatic test equipment(ATE), comprising: adding jitter to a test signal to produce a jittered signal; sampling the jittered signal to produce digital values, wherein sampling is performed using an under-sampling technique that samples the jittered signal in multiple cycles, and wherein, in a current sampling cycle, sampling is performed at substantially regular offsets relative to sampling performed in a previous sampling cycle such that different parts of the jittered signal are sampled in different cycles; generating a reconstructed jittered signal from the digital values; determining an amount of jitter in the reconstructed jittered signal,wherein determining the amount of jitter in the reconstructed signal comprises obtaining a difference between a maximum edge time and minimum edge time in the reconstructed jittered signal; wherein the amount of jitter in the reconstructed jittered signal includes jitter introduced by two or more hardware elements; wherein an amount of jitter added to produce the jittered signal is predicted and an amount of jitter introduced by the two or more hardware elements is unexpected; and calibrating the ATE based on the amount of jitter in the reconstructed jittered signal.