Achieving Accurate Timing Measurements on TTL/CMOS Devices

Production TTL and CMOS timing measurements obtained between different test systems and between test systems and the bench setup often do not correlate or do not appear to be accurate even though the automatic test equipment system has subnanosecond accuracy. Errors of as much as 2 ns can occur with small-, medium-, and large-scale integration and with gate arrays using the new TTL and CMOS technologies. This represents a 100- percent error factor for these emerging products.