A new chip fuse offers temperature-sensitivity suitable for both over-current protection and protection against excessive ambient temperatures.
The USN 1206 from Schurter is not a pure thermal fuse, per se. It requires a current flow to blow, thus providing protection against over-current, just as well as any conventional fuse. In addition, it is also designed to protect power semiconductors in automotive applications against over-temperature. The fuse has a current-time characteristic which shifts as a function of the ambient temperature. As a result, a specific trigger at a certain threshold value can be achieved with rising temperature. The 12-A current-rated USN 1206 has high I2
t values at 32 Vdc and a slow blowing characteristic. It has a breaking capacity of 80 A at 32 Vdc and 170 A at 16 Vdc with an operating temperature range of a -40 to a +125°C.
The Schurter USN 1206 meets the AEC-Q200 standard making it suitable for automotive applications requiring the highest reliability under particularly difficult conditions (heat, vibration, mechanical and cyclic strength). Qualification is according to each unique customer requirement on request. The production and qualification of the fuse takes place in agreement with the customer according to the requirement profile of the desired time-current tripping characteristic as a function of the ambient temperature.
Additionally, the USN 1206 is a good choice wherever temperature-critical processes arise, or even when a specific intrinsic characteristic is required. The temperature-sensitive SMD fuse is reflowable at 245°C according to IEC 60068-2-58. The epoxy glass housing makes it tight against the potting compound, thus making the fuse suitable for explosion-proof applications according to ATEX / IECEx as well. UL approval can be obtained.
Pricing for the USN 1206 series starts at under $0.50 each in 500 piece quantities. Packaging is 100 pieces.