SMD Fuse Combines Over-Temperature and Overcurrent Protection
Schurter’s USN 1206 offers a temperature-sensitive SMD fuse suitable for both overcurrent protection and protection against excessive ambient temperatures.
Due to the ever-increasing packing density in power electronics, it is becoming ever challenging to deal with the tighter and hotter board real-estate. Automobile manufacturers increasingly use control units in their products, including power electronics (e.g. ABS modules, annealing time control units, actuators, etc.).
The trend is to integrate as many functions as possible into the smallest possible space in a single module. The fact that such modules must be protected against overcurrent is self-evident. However, the increasing power density also entails thermal problems. For this purpose, new approaches are needed to avoid a creeping risk of overheating.
The USN 1206 has been developed as an SMD temperature protection device for power semiconductors (e.g. MOSFETs) in automotive applications. At the same time, it also provides protection against overcurrent.
The USN 1206 from Schurter has high I2t values (slow characteristic) and a rated current of 12A at 32Vdc. 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 USN 1206 from Schurter is not a pure thermal fuse. It needs a current flow to trigger. The temperature-sensitive SMD fuse is therefore reflowable at 245 °C according to IEC 60068-2-58. The epoxy glass housing makes it tight against the potting compound. Thus, the fuse is also suitable for explosion-proof applications according to ATEX / IECEx.
Due to its design, the new Schurter USN 1206 is particularly suitable for automotive applications requiring the highest reliability under particularly difficult conditions (vibration, mechanical and cyclic strength, etc.).
The production and qualification of the fuse is carried out in agreement with the customer according to the requirement profile of the desired time-current tripping characteristic as a function of the ambient temperature.
In addition, it is also used wherever temperature-critical processes occur, or even when a specific intrinsic characteristic is required, which is the case in almost all applications with power semiconductors.
- All electronics with temperature-critical components (eg MOSFET's)
- Applications where high reliability is needed
- Fail-Safe applications
- Automotive
