M1 Oscilloscope Tools™: PLL Toolkit

When designing or using PLLs with intentional modulation (e.g. SSC), there are a number of important parameters that you need to understand to get the design right. If that PLL will be used in parallel with another PLL, additional parameters related to the separation between the signals become important as well.

M1 OT's PLL Toolkit was designed to quickly bring together in one place all of the most important values that you need to know about, and present them in a highly graphical manner that allows you to easily understand where each value comes from. Of course, if you need to dig deeper, at the click of a button any of the parameters can be plotted vs time so that you can explore the data with all the power that M1 OT has to offer.

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An important innovation in the PLL Toolkit is the inclusion of Constructed Separation values along with the measured values. Trying to find true worst-case separation values by direct measurement is not advisable, as you are hoping to catch the simultaneous occurrence of several rare events at once. A better method is to measure only the mean separation between the signals, and then use parameters calculated individually from each signal to construct the theoretical worst-case separation values.

When you get down to basics, there are only three pathological mechanisms that will cause a device to fail: a short cycle, a large displacement (cycle-cycle) failure, or an accumulated error failure. The Standard Critical Path Analysis (SCPA) screen of the PLL Toolkit brings these three values together in one place for easy reference, together with diagrams that show how each of the pathologies causes a failure.

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