Patents Assigned to NPTest, LLP
  • Patent number: 6661836
    Abstract: A jitter measurement technique utilizing a high-bandwidth undersampling voltage measurement instrument is presented. A trigger is derived from the a signal having a repetitive signal pattern. The signal is compared with a threshold at a plurality of times relative to the trigger during multiple repetitions of the signal pattern to produce measurement samples indicative of signal level relative to the threshold. The measurement samples are used to determine the probability of signal edge states as a function of time for the multiple repetitions. The probability of signal edge states are used to determine an edge probability density as a function of time. A histogram of signal state transition times can be prepared from the edge probability density. Mean deviation of edge transitions of the signal can be estimates, and standard deviation of edge transitions of the signal can be estimated to give the root-mean-square (rms) jitter of the signal.
    Type: Grant
    Filed: October 17, 1999
    Date of Patent: December 9, 2003
    Assignee: NPTest, LLP
    Inventors: Wajih Dalal, Daniel A. Rosenthal