High-Power Fuse Packs Value-Added Features

The STEF01 programmable electronic fuse from STMicroelectronics handles up to 4A continuous current over a wide operating input-voltage range of 8V to 48V, with low insertion loss thanks to a low-RDS(ON) VIPower MOSFET. When connected in series to the main power rail, the STEF01 protects the load against over-current and over-voltage. The voltage is clamped to a user-defined maximum, preset with external resistors. Excessive current is restricted to the programmed safe limit by controlling the internal power MOSFET, and folds back to a lower limit if a strong over-current or short-circuit is detected. 


The STEF01 leverages the company’s BCD8 high-voltage process to integrate value-added features, including dV/dt control to prevent excessive inrush current during startup or hot-swap insertion. This slows the output-voltage ramp-up time to at least 3 ms, which can be increased if desired by connecting an external capacitor. Programmable Under-Voltage Lockout (UVLO), also set using external components, allows the user to fine-tune the desired voltage-rail minimum value to suit the load requirements.


Other features include thermal shutdown with latching or auto-retry, maximum dissipated-power protection, a power-good indicator, and an enable/fault pin that can be used as either a status monitor or to control the device. A dedicated gate-driver output for controlling an external N-channel MOSFET simplifies implementation of reverse-current protection.


The STEF01 is available now in a 14-pin HTSSOP14 package, priced from $1 each/1,000 pieces. For further information, download the STEF01 datasheet.