Under contract with Signetics, Mr. Thomas J. Chaney of Washington University, St. Louis tested a set of nineteen 74F786 samples (packages) to determine the metastable state recovery statistics for the circuits. The tests were conducted using a procedure described in a paper entitled “Characterization and Scaling of MOS Flip-Flop Performance”, (section IV), by T. Chaney and F. Rosenberger, presented at the CalTech Conference on VLSI, January 1979. The general test procedure was to test all 19 packages under one condition, then test the best, worst, and an average package in more detail. According to Mr. Chaney, the test results from the 19 packages formed one of the tightest groupings that he has ever seen. As the parts were numbered, package No. 7 had the fastest resolving times, No. 11 produced some of the slowest resolving times, and No. 1 had resolving times near the middle of the test results. This ranking of the test results from 3 packages remained the same throughout the balance of the test program, which supports the complete testing of only 3 packages. In general, the poorest performance resulted when the packages were heated to near 75°C with VCC = 4.5VDC and the best performance resulted when the packages were cooled to near 0°C with VCC = 5.5VDC. The variation within one package caused by the temperature and VCC changes was greater than the variation from package to package. It must be noted that none of the packages tested even approached the data sheet input to output worst case propagation delay of 10.5ns. All the packages tested for a single active output, had propagation delays of about 6ns. Typically, the parts with longer propagation delays also have slower resolving times. Thus, one would expect that the delay time needed to have only one failure in 32 years using a 10ns propagation delay part would be much longer than a value derived from just adding 10–6 = 4ns to the above calculations. thus it appears that the poorest performance measured in this study should be considered a measurement at the edge of the typical range for 74F786 parts. It must also be noted that the tight grouping of this set of packages means that, when comparing differences between these test results, the measured error, as outlined in “Measured Flip-Flop Responses to Marginal Triggering”, IEETC, December 1983, is significant. This is illustrated in association with Table 5.