STEF12 Datasheet Electronic fuse for 12 V line Features Continuous current (typ): 3.6 A N-channel on-resistance (typ): 53 m Enable/Fault functions Output clamp voltage (typ): 15 V DFN10L (3x3 mm) Undervoltage lockout Short-circuit limit Overload current limit Controlled output voltage ramp Thermal latch (typ): 165 C Operating junction temp. - 40 C to 125 C Available in DFN10 (3x3 mm) package Applications Hard disk drives Solid state drives (SSD) Hard disk and SSD arrays Set-top boxes DVD and Blu-ray disc drivers Maturity status link Description STEF12 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 signal led 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. DS7315 - Rev 7 - February 2020 www.st.com For further information contact your local STMicroelectronics sales office.STEF12 Device block diagram 1 Device block diagram Figure 1. Block diagram DS7315 - Rev 7 page 2/21