Measuring the upset of CMOS and TTL due to HPM-signals

摘要

To measure the performance of electronic componentswhen stressed by High Power Microwave signals asetup was designed and tested which allows a well-definedvoltage signal to enter the component during normal operation,and to discriminate its effect on the component. style="line-height: 20px;">The microwave signal is fed to the outside conductor of acoaxial cable and couples into the inner signal line connectedto the device under test (DUT). The disturbing HF-signal istransferred almost independent from frequency to maintainthe pulse shape in the time domain. The configuration designedto perform a TEM-coupling within a 50 Ohm systemprevents the secondary system from feeding back to the primarysystem and, due to the geometrical parameters chosen,the coupling efficiency is as high as 50–90%. Linear dimensionsand terminations applied allow for pulses up to a widthof 12ns and up to a voltage level of 4–5 kV on the outsideconductor. These pulse parameters proved to be sufficient toupset the DUTs tested so far. style="line-height: 20px;">In more than 400 measurements a rectangular pulse ofincreasing voltage level was applied to different types ofCMOS and TTL until the individual DUT was damaged. Aswell the pulse width (3, 6 or 12 ns) and its polarity were variedin single-shot or repetitive-shot experiments (500 shotsper voltage at a repetition rate of 3 Hz). The state of the DUTwas continuously monitored by measuring both the currentof the DUT circuit and that of the oscillator providing theoperating signal for the DUT. style="line-height: 20px;">The results show a very good reproducibility within a setof identical samples, remarkable differences between manufacturersand lower thresholds for repetitive testing, whichindicates a memory effect of the DUT to exist for voltagelevels significantly below the single-shot threshold.