Due to the ever-increasing packing density in power electronics, thermal problems must be considered when protection features are designed. USN 1206 has been developed as an SMD temperature protection device for power semiconductors in automotive applications. At the same time, it also provides protection against overcurrent. It offers I2t values (slow characteristic) and a rated current of 12A at 32 VDC. The fuse has a current-time characteristic which shifts as a function of the ambient temperature. As a result, a specific opening at a certain threshold value can be achieved with increasing temperature. The device is not a pure thermal fuse, requiring a current flow to trigger, so despite being temperature-sensitive it is reflowable at 245C according to IEC 60068-2-58. The epoxy glass housing seals it against potting compound. The fuse is therfore suitable for explosion-proof applications according to ATEX / IECEx.
The device is suitable for automotive applications requiring the highest reliability under particularly difficult conditions (vibration, mechanical and cyclic strength, etc.) and can be qualified to AEC-Q200 on request. Specific profiles of the desired time-current tripping characteristic as a function of the ambient temperature can be defined.