STEF033 Electronic fuse for 3.3 V line Datasheet - production data Description The STEF033 is an integrated electronic fuse optimized for monitoring output current and the input voltage. Connected in series to the 3.3 V rail, it is able to protect the electronic circuitry on its output from overcurrent and overvoltage. The STEF033 has controlled delay and turn-on time. DFN10 (3 x 3 mm) Flip Chip 9 When an overload condition occurs, the device 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 Features short-circuit is present on the board, when the power is re-applied the eFuse initially limits the Continuous current typ.: 3.6 A (DFN), 2.5 A output current to a safe value and then goes (Flip Chip) again into the open state. The voltage clamping N-channel on resistance (typ): 40 m (DFN), circuit prevents the output voltage from exceeding 25 m (Flip Chip) a fixed value, if the input voltage goes beyond this threshold. The device is equipped with a thermal Enable/Fault functions protection circuit. Intervention of thermal Output clamp voltage (typ): 4.5 V protection is signaled to the board-monitoring Undervoltage lockout circuits through an appropriate signal on the Fault pin. Unlike mechanical fuses, which must be Short-circuit limit physically replaced after a single event, the eFuse Overload current limit does not degrade in its performances following Controlled output voltage ramp short-circuit/thermal protection intervention and is reset either by re-cycling the supply voltage or Thermal latch (typ): 160 C using the appropriate Enable pin. The STEF033 Uses tiny capacitors is also available in an auto-retry version in case Latching and auto-retry versions of thermal fault it automatically attempts to re- apply power to the load when the die temperature Operative junction temp. - 40 C to 125 C returns to a safe value. Available in DFN10 3x3 and Flip Chip 9 bumps Applications Hard disk drives Solid state drives (SSD) Hard disk and SSD arrays Computer DVD and Blu-Ray disc drivers November 2020 DocID025099 Rev 4 1/25 This is information on a product in full production. www.st.comContents STEF033 Contents 1 Device block diagram 3 2 Pin configuration 4 3 Maximum ratings 5 4 Electrical characteristics . 7 5 Typical application 9 5.1 Operating modes 9 5.1.1 Turn-on 9 5.1.2 Normal operating condition 10 5.1.3 Output voltage clamp . 10 5.1.4 Current limiting 10 5.1.5 Thermal shutdown and Auto-retry function 10 5.2 R calculation 10 Limit 5.3 C calculation .11 dv/dt 5.4 Enable-Fault pin .11 6 Typical performance characteristics . 13 7 Package information 16 7.1 DFN10 (3x3 mm) package information 17 7.2 QFNxx/DFNxx (3x3 mm) packing information . 20 7.3 Flip Chip 9 package information 21 8 Order codes . 23 9 Revision history . 24 2/25 DocID025099 Rev 4