Temperature-Sensitive SMD Fuse

September 24, 2017

Jennifer Shuttleworth

Schurter’s (Santa Rosa, CA) USN 1206 chip fuse offers temperature sensitivity suitable for both overcurrent protection and protection against excessive ambient temperatures. According to Schurter, the USN 1206 is not a pure thermal fuse, per se. The company claims it requires a current flow to blow, thus providing protection against overcurrent just as well as any conventional fuse. It is also designed to protect power semiconductors in automotive applications against over-temperature. The fuse has a current-time characteristic that shifts as a function of the ambient temperature. As a result, a specific trigger at a certain threshold value can be achieved with increasing temperature. The 12-A current rated USN 1206 has high I2t values at 32-V dc.