Schurter's RTS thermal fuse, successfully launched in 2018, gets a new variant with a tripping temperature of >175°C. The RTS is a particularly compact over temperature protection device for power semiconductors in SMD technology for highest demands.

RTS stands for Reflowable Thermal Switch. It was developed to protect highly integrated power semiconductors from overheating. Prior to mechanical activation, the new thermal fuse can be soldered on conventional reflow soldering machines with profiles up to 260°C.

Protection against thermal runaway

Thermal runaway refers to the overheating of a power semiconductor due to a self-reinforcing, heat-producing process. One of the reasons is the trend towards increasing power density and miniaturisation of electronic circuits. The RTS protects these power semiconductors against thermal runaway. In such an event, the thermal fuse acts as a fail-safe device and reliably interrupts the circuit from as early as 175°C and thus addresses the operating temperatures of common power semiconductors even better.

Minimal footprint

The new overtemperature protection device comes in the same minimal dimensions and maximum breaking capacity despite its additional shunt functionality. On its small 6.6 x 8.8 mm footprint the RTS can handle operating currents of up to 130 A and rated voltages of up to 60 VDC.

Integrated current measuring sensor (shunt)

The shunt version has an integrated resistance with particularly low temperature dependence. This resistance, known as a shunt, enables precise current measurement and enables an additional – non-thermal – circuit protection, e.g. via a controller.