The STEF05D is an integrated electronic fuse optimized for monitoring output current and input voltage. Connected in series to a 5 V rail, it is capable of protecting the electronic circuitry on its output from overcurrent and overvoltage. The device has a controlled delay and turn-on time. When an overload condition occurs, the STEF05D limits the output current to a predefined safe value. If the anomalous overload condition. persists, it goes into an open state, disconnecting the load from the power supply. If a continuous short-circuit is present on the board, when power is re-applied the E-fuse initially limits the output current to a safe value, and then again goes into an open state.
The device is equipped with a thermal protection circuit. The intervention of the thermal protection is signal led to the board monitoring circuits through a signal on the Fault pin.
Unlike mechanical fuses, which must be physically replaced after a single event, the E-fuse does not degrade in its performance after short-circuit/thermal protection interventions and it is reset either by recycling the supply voltage or using the Enable pin.
The companion chip for 12 V power rails is also available with part number STEF12.