STMicroelectronics STEF4S
The STEF4S is an integrated electronic fuse optimized for monitoring the output current and the input voltage. It can be connected in series to 3.3 V or 5 V rails, protecting the electronic circuitry on its output from overcurrent and overvoltage. The operating mode (5 V or 3.3 V) can be selected by a dedicated pin.FEATURES
● Power MOSFET on-resistance (typ.): 40 mΩ● Enable function
● Output clamp voltage (typ.): 5.7 V in 5 V mode, and 3.8 V in 3.3 V mode
● Undervoltage lockout
● Short-circuit limit
● Overload foldback current limit
● Controlled soft-start
● Thermal auto-retry
● Internal sensing FET
● Operative temp. range: - 40 °C to 85 °C
● Available in DFN 3x3 10L package
DESCRIPTION
The STEF4S has a controlled turn-on time, adjustable by an external capacitor. When an overload condition occurs the device limits the output current to a Datasheet - production data 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, the E-fuse limits the output current to a safe value. In case of overvoltage on the input, the device clamps the output voltage to a predefined value and protects the load. If the anomalous fault condition persists, the internal thermal protection circuit shuts down the device and then automatically attempts to resupply the load until the fault condition is removed.