DEV-15046

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 E-fuse 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 E- Overload current limit fuse does not degrade in its performances Controlled output voltage ramp following short-circuit/thermal protection intervention and is reset either by re-cycling the Thermal latch (typ): 160 C supply voltage or using the appropriate Enable Uses tiny capacitors pin. The STEF033 is also available in an auto- Latching and auto-retry versions retry version; in case of thermal fault it automatically attempts to re-apply power to the Operative junction temp. - 40 C to 125 C load when the die temperature returns to a safe Available in DFN10 3x3 and Flip Chip 9 bumps value. Applications Hard disk drives Solid state drives (SSD) Hard disk and SSD arrays Computer DVD and Blu-Ray disc drivers January 2015 DocID025099 Rev 2 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 (3 x 3 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 2