FUSE BURNOUT DUE TO GATE DRIVE CIRCUIT PARASITIC RINGING IN DC/DC CONVERTERS

摘要

DC/DC converters sometimes suffer failures. Some of these failures are related to components or assemblies, such as burned MOSFETs, cracked packages, ferrite core cracks, and broken capacitors. These failures are commonly attributed to overstress from electrical, thermal, or environmental sources. Much attention is given to these reliability problems. However, other failures are more subtle. One example is the burnout of a subsidiary input line fuse, resulting in no output from the DC/DC converter. This failure generally occurs at power-up and possibly more often when a converter is powered up a short time after the last power-off. If the failed fuse is repaired, the DC/DC converter returns to normal and can continue to work. The root cause of this failure is difficult to analyze - and the corresponding waveform is hard to capture - because it occurs in an instant, and the fuse will commonly protect DC/DC converters from further failures. This failure is most often associated with the design robustness of DC/DC converters. Yet, thus far, failure analysts have paid little attention to this problem.