Reliability Analysis of Transient Voltage Suppression Diodes Under Direct Current Switching Surge Stress

This study examined the dependability of Transient Voltage Suppression (TVS) diodes under direct current (DC) switching surge stress from several manufacturers with identical electrical requirements. To prevent thermal damage, we applied a standard 3 ms DC switching surge and increased the surge voltage in increments of 0.1 V with intervals between surges. The breakdown voltage (VBR) was measured after each DC switching surge to verify functionality. To find the maximum surge current and power level that each device could withstand before failing to clamp surge voltage at a defined VBR level, three separate manufacturers’ TVS diode (VBR = 6.8 V) samples were examined. There were significant variations in the computed maximum average surge current and power level between manufacturers’ samples determined by statistical analysis. Prior to failure, the average surge power was 202 W, 321 W, and 357 W, while the maximum average surge current was 29.0 A, 46.9 A, and 51.8 A, respectively. Computed 95% confidence interval ranges between manufacturers of TVS diodes revealed significant population reliability differences under DC switching surge stress. Therefore, an efficient TVS diode reliability metric for DC switching surge stress is the maximum average surge current and power immediately before device failure.