■ Continuous current (typ): 3.6 A

■ N-channel on-resistance (typ): 53 mΩ

■ Enable/Fault functions

■ Output clamp voltage (typ):15 V

■ Undervoltage lockout

■ Short-circuit limit

■ Overload current limit

■ Controlled output voltage ramp

■ Thermal latch (typ): 165 °C

■ Uses tiny capacitors

■ Operating junction temp. - 40 °C to 125 °C

■ Available in DFN10 (3 x 3 mm) package

■ Hard disk drives

■ Solid state drives (SSD)

■ Hard disk and SSD arrays

■ Set-top boxes

■ DVD and Blu-Ray disc drivers

The STEF12 is an integrated electronic fuse optimized for monitoring output current and input voltage. Connected in series to a 12 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 STEF12 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 signalled to the board monitoring circuits through a signal on the Fault pin. Unlike the mechanical fuses, which must be physically replaced after a single event, the Efuse 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 the 5 V power rails is also available with part number STEF05.