STEF05 Electronic fuse for 5 V line Datasheet production data Features Continuous current (typ): 3.6 A N-channel on-resistance (typ): 40 m Enable/Fault functions Output clamp voltage (typ): 6.65 V Undervoltage lockout Short-circuit limit Overload current limit DFN10 (3x3 mm) Controlled output voltage ramp Thermal latch (typ): 165 C Uses tiny capacitors Operating junction temp. - 40 C to 125 C persists, it goes into an open state, disconnecting the load from the power supply. If a continuous Available in DFN10 (3x3 mm) package short-circuit is present on the board, when power is re-applied the E-fuse initially limits the output Applications current to a safe value, and then again goes into an open state. The device is equipped with a Hard disk drives thermal protection circuit. The intervention of the Solid state drives (SSD) thermal protection is signalled to the board Hard disk and SSD arrays monitoring circuits through a signal on the Fault pin. Unlike mechanical fuses, which must be Set-top boxes physically replaced after a single event, the E- DVD and Blu-ray disc drivers fuse does not degrade in its performance after short-circuit/thermal protection interventions and Description it is reset either by recycling the supply voltage or using the Enable pin. The companion chip for The STEF05 is an integrated electronic fuse 12 V power rails is also available with part number optimized for monitoring output current and input STEF12. voltage. Connected in series to a 5 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 STEF05 limits the output current to a predefined safe value. If the anomalous overload condition Table 1. Device summary Order code Package Packaging STEF05PUR DFN10 (3x3 mm) Tape and reel January 2013 Doc ID 019055 Rev 5 1/20 This is information on a product in full production. www.st.com 20Contents STEF05 Contents 1 Device block diagram 3 2 Pin configuration 4 3 Maximum ratings 5 4 Electrical characteristics . 6 5 Typical application 8 5.1 Operating modes 8 5.1.1 Turn-on . 8 5.1.2 Normal operating condition . 9 5.1.3 Output voltage clamp 9 5.1.4 Current limiting . 9 5.1.5 Thermal shutdown 9 5.2 R limit calculation 9 5.3 Cdv/dt calculation 9 5.4 Enable/Fault pin 10 6 Typical performance characteristics . 12 7 Package mechanical data 15 8 Revision history . 19 2/20 Doc ID 019055 Rev 5