Features
• Continuous current typ. 3.6 A
• N-channel on-resistance typ. 45 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 (3x3 mm) package
• UL2367 Recognized - File N. E468771

Applications
• Hard disk drives
• Solid state drives (SSD)
• Hard disk and SSD arrays
• Set-top boxes
• DVD and Blu-ray disc drivers

Description
The STEF12E 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
STEF12E 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.