Inventors:
Willard MacDonald - San Francisco CA
Mark J. Woodward - Santa Rosa CA
Stephen W. Hinch - Santa Rosa CA
Assignee:
Agilent Technologies Inc. - Palo Alto CA
International Classification:
H03M 112
Abstract:
An internally triggered equivalent-time sampling system characterizes high-speed data signals having a predetermined nominal data rate by using an internal oscillator that runs independent of a synchronous trigger signal. The sampling system acquires samples of the data signal at a strobe rate, set by the oscillator, which is lower than the nominal data rate of the data signal. The samples, the strobe rate, and the nominal data rate are communicated to a quality optimizer which compensates for static rate deviations between the nominal data rate and the actual data rate of the data signal to establish timing correspondence between the acquired samples. The timing correspondence establishes the time placement of the acquired samples when characterizing the data signal on a display or other output device. When the oscillator has high timing stability relative to the data signal, jitter and other attributes of the data signal are accurately characterized.
